BONUS PROJECTS' BLOGS
Below are the most recent entries in the BONUS projects' blogs. To read the entries of your favorite project, select it from the list on the left.
01.08.2017 22:23Equipment explained: part IV - the HAPS corer (Sources & Sinks: A Tale of Coastal Biogeochemistry - BONUS COCOA)
This post might as well be entitled “Ode to HAPS”. For one thing, the HAPS corer is by far my favorite sediment sampler, clearly deserving of being sung about. For another thing, it already has been (cruise internally) sung about, showing that not only I have a personal affection for it, but that it is popular among several COCOA people (aka the HAPS gang).
So what is this HAPS sampler and what is so special about it?
The HAPS is a sediment corer for coarse sediments, i.e. sands. The tricky parts with sand sediments are that they are quite hard and sturdy, and that they have big pores, which impose only weak cohesive forces onto the pore water. This can result in water actually flowing through the pore space of sand (advective pore water flow), which has everyone experienced who ever saw a wave washing up a beach…and then disappearing into the sand under the own feet.
Pore water flow has huge implications for organic matter turnover, sediment biogeochemistry, and general elemental cycling- however, in terms of sampling, it means particularly one thing: how not to lose the pore water during core retrieval, if it´s so mobile? (In more plain words: pore water flow in sand is scientifically and ecologically really cool stuff, but it does add a challenging element to undisturbed sampling of sand sediments).
Luckily, there is the HAPS!
We wondered for years, what its name stands for (maybe “happy and prosperous sampling”?!), until getting the answer from the inventors themselves (Kanneworff & Nicolaisen 1973): apparently, “haps” is a Danish exclamation used when something is grasped very quickly. And that´s exactly what the HAPS does: after coring, a tight top lid keeps the sediment in the core, and during core retrieval, a super sharp, quick and tight shovel cuts immediately under the sediment core, so that pore waters are kept where they belong- in the sediment. However, never forget to use the core lid, otherwise also the super quick shovel does not help in holding any sample (*learned from experience*).
This sounds like basic sediment coring theory. Yet, the difference of the HAPS to e.g. the GEMAX corer is its weight, its stability and the speed of its closing mechanism.
Like the GEMAX (Equipment explained: part II - the GEMAX / GEMINI corer), HAPS is basically a gravity corer, i.e. it cuts into the sediment based on its own weight. But even if GEMAX does feel heavy when loading it onto the ship, it is too light to be able to cut into sand sediment. Plus, sands are usually located in high energy environments (too turbulent for finer particles to settle), where samplers need to be heavy to go down the water column and onto the sediment surface without being drifted away. The net weight of a HAPS corer is ~ 100 kg, which can be added up by additional 60 kg of lead weights, and a square bottom frame supports high stability at the sea floor. It is made out of stainless steel, including the core barrel and the closing shovel, which are both sharpened for uncompromising sediment penetration. If the weight of a fully loaded sampler should still be too light to penetrate the sediment, it can be equipped with a powerful vibrator unit. Insider tip: don´t drive it for too long, you might anchor yourself in the seafloor.
Undisturbed samples are easily to be seen in the clear water phase on top of the sediment, which during our sampling at the Finnish coast sometimes also included Saduria sp., having been surprised by the quick sampling (Killing in the name of).
Well, HAPS got its name for a reason.
20.07.2017 12:00EAERE 2017 (BONUS BALTICAPP - Race Against Eutrophication Blog)
In this blog I will tell about the EAERE conference held in Athens. First I must emphasize that it was really hot out there. I have never experienced such a hot temperatures (35-45 degrees) in my life before. Luckily the air conditioning worked just well in the conference places and all the other facilities were also very well handled. Overall the conference was a good and learning experience. I witnessed some great presentations and speeches. I guess that the best presentations (among those I saw) focused on micro-econometric data analysis and intertemporal optimization. I guess that it was particularly beneficial to see the overall level and current trends in environmental economics. It appears that macro models and everything related to climate change is now cool. Also behavioral and network economics appear to be very hot fields right now. My subject of interest, namely empirical agricultural production analysis and agri-environmental modelling seems rather uninteresting subject currently, to say at least. But that’s ok, I keep calm and continue working with my PhD anyway. At least I am still excited about it (now that I’m working with the second paper)!
There was also one very good plenary speech, which handled multiple layers of uncertainty, including model selection uncertainty. I found this particularly interesting, of course, because I have been struggling with uncertainty (regarding particularly model selection) issues for so long time now. I actually started to loose my interest in structural uncertainty entirely. But now it seems that it might actually be the key to get my first paper published. I got this idea that perhaps I should reframe the problem so that the focus is, again, shifted to these structural uncertainty issues within the optimization problem. It would be absolutely perfect if I could find a way to formulate the profit maximization problem analytically so that the parametric and model selection uncertainty would be taken into account explicitly. This, however, might be very challenging and perhaps beyond my abilities, given the time limits at least. But in any case, I should stress the structural uncertainty, because it appears to be generally interesting topic after all; for a moment I thought I was the last person on earth interested in it.
My presentation in the conference went just fine. Needless to say I was very nervous about it. The audience wasn’t large, which was just fine. One reason for the lack of audience, among the fact that nobody is generally interest in empirically bio-economic modelling in the context of agriculture (or fertilizers (!)), might have been that it was a last parallel session before the dinner and the busses started to leave just after the session. I guess most of the people went to hotel to rest and get ready for the evening. Anyway, I got some comments for some Chinese senior researcher, which was very nice, although I couldn’t understand her comments at the moment, because of the very challenging accent. However, after reprocessing the echoes in my ears for a while I understood what she said. Anyway, the comments were very trivial and I’m a little bit upset that I couldn’t respond to those at the moment, but better luck next time perhaps. I also was a discussant for a one presentation in our session. I think it went well and the situation resolved rather nicely in the end. The dinner, by the way, was great and we had very good time. Even the head master of the Greek bank was there to give his speech, which was super funny (the speech I mean).
I must say that I didn’t seize the opportunity to network with foreign people at all, which was a little bit unfortunate. The thing is that there was such a huge amount of Finnish environmental economists there that most of the time we just chatted with each other in some isolated corner. And during the dinner we also had Finnish tables. Luckily some German researches shared a table with us in the end. Thus, some international communications did take place, but not much. Anyway, it was a very nice event and all. I really hope that I could participate the next one also (which will be held in Gothenburg), but it will be much more unlikely because it will be a world conference so the competition will be much tougher. I know for a fact that the second paper will be much more interesting in terms of environmental economics than the first one, but will it be enough, remains to be seen. It would be nice to see the Gothenburg because it is capital if Scandinavian Heavy Metal!
Thus, Rock on and see you next month!
Bets regards: Matti Sihvonen
05.07.2017 15:03How can Sweden help bridge the gap between innovation and commercialisation in the Baltics? (BONUS RETURN)
04.07.2017 21:57An affair of the heart (Sources & Sinks: A Tale of Coastal Biogeochemistry - BONUS COCOA)
And here it comes: my drawing turned out to be dominated by hearts. Hearts around N2. In relationship with a gas? Well, that does solve the problem of “plus avec” invitations via “take a breath of air”, but of course there was also a deeper meaning in using the symbols. Take a look at the drawing / bar-scribble, for better understanding re-coloured:
The 30 sec explanatory
talk went somewhere along the lines of....
“The Baltic Sea in northern Europe has too
many nutrients, mostly nitrate, which leads to algae blooms (--> green scribble) and oxygen
deficiency, so the sea is in bad ecological condition (--> sad smiley). The only way to remove
nitrogen from an aquatic ecosystem is via denitrification and anammox, which
results in N2 that goes into the air (--> that´s good *at least in a
eutrophic system* --> HEARTS). Estuaries are recognized as potential
hot spots of nitrogen removal and these are the 3 estuaries I looked at.“ FULL
STOP and a deep breath.
Don´t put me down on scientific spotless accuracy, but nevertheless, my piece of art & speech was convincing enough to score second place. Now I am proud owner of a new coffee cup.
The conference was rounded up by a hike in the national park Bic at the St. Lawrence Stream on World Ocean Day, strengthening our attachment to the biggest estuary of the world.
Thanks UQAR for organizing such an interesting symposium!
29.06.2017 12:36Engaging cities and municipalities to clean up the Baltic Sea (BONUS RETURN)
26.06.2017 20:10Most of the Baltic zooplankton is specialized on small food (The view of a data scientist - BONUS BIO-C3 & BONUS INSPIRE)
22.06.2017 16:09Keep calm and listening the Kocinka (Storm in a teacup - water is everywhere BONUS SOILS2SEA)
Hi to all very busy people,
swiming aginst main stream of life in neverending haste, I want to invite you to relax on the Kocinka side.
It takes ONLY one minute...
Pictures from last field trip - June 2017:
20.06.2017 10:45BONUS RETURN kicks off (BONUS RETURN)
A new EU funded project aimed at turning waste into profit officially kicked off in Sweden with a conference on 19th and 20th June at Sånga Säby. Members from Sweden, Finland and Poland, gathered in the north of Stockholm to set strategies for the three-year long project.
05.06.2017 09:26Upsides and downsides, mostly downsides.. (BONUS BALTICAPP - Race Against Eutrophication Blog)
We had a very interesting PhD course on econometrics in Bergen Norway. We were introduced to modern methods of empirical data analysis including instrumental variables, differences-in-differences and regression discontinuity. The topics of the examples were from environmental and resource economics and included themes such as relationships between conflicts and resource discoveries, price shocks and civil conflicts, the political resource curses and environmental speed limits in Oslo. The course took three days. During the visit in Bergen we also got an opportunity to explore the beautiful city (or village). The surrounding mountains were particularly impressive. It also became apparent that the Bergen is a rather rainy place; there is approx. 300 rainy days a year, we were told. It also became clear that Norway is a very expensive country. The oil money seems to increase the prices beyond the level that at least we Finnish people would consider reasonable. The get the points from the course we have to hand in a home assignment by the end of the September. In this assignment we are asked to get some data related to our PhD research and to explore the data via some method introduced in the course. Then we are asked to write a paper about the data, method applied and the results. Thus, if data are good, one could expand this home assignment to a real paper. This is of course what I am planning to do if I get good data. Therefore the quest for data is now one of the priorities during the summer. I was thinking about data regarding some policy or regional shift. Thus, for example, data could be about an effect of a subsidy policy on different agricultural regions. Then I could apply regression discontinuity method for the data analysis.
We also had another PhD course, namely a project management course. However, although the lecturer was very good and inspirational person, I did not found the course very useful. I took it mostly as a language improving exercise than anything else since I have no interests in project management or managing in general. Of course it is useful to be able to manage ones own work but I don’t think that getting a course on that is very useful. Anyway, I’m sure that some participants did found the course useful and we did have some delightful conversations during the course.
There was also a third PhD course, namely Economic Growth and Natural Resources. We had to hand in some home assignments and then there was an exam. This was very interesting course because the topic was in the field of macroeconomics, which I am not familiar with. Therefore it was good introduction to the unexamined territory. Macroeconomics is good for environmental economist because most of the macroeconomic analysis is dynamic. Therefore I might take another macro course in September, which focuses on dynamic optimisation methods. I think it might be particularly useful for me.
It has also become clear that to publish a paper is rather hard task. We got a refusal from a first journal because “the article did not fit the scope of the journal”. The refusal, however, might have been a fortunate thing because the journal, namely the Environmental modelling and software, was probably not a good journal for the article because in the first paper we did not model any environmental aspects. The first paper discussed simply agricultural system consisting of nitrogen and phosphorus yield responses and the development of soil phosphorus. Therefore the scope of the article is clearly agriculture and not environment, although those two scopes are quite related. Only after the refusal I started to understand that the scope of the journal is rather important thing. I started to examine the potential journals for our paper. During this examination I realised that our paper is kind of a weird mixture of data analysis and optimisation. Therefore it might be difficult to find a journal that would consider the paper a good fit for the scope. Anyway, I did submit the paper for another journal and I am now waiting for a refusal or some other answer. I just hope that it will be accepted to some journal since the second paper is a direct extension for the first paper.
The refusal also reminded me of the saying of Hannu Vartiainen after the first Microeconomic lecture: “the PhD work consists of upsides and downsides, mostly downsides”. It certainly is so that the work has been mostly downsides and there have been times when I have considered calling my model a setback-model because there have been so many setbacks down the road.
The second, and actually the most important priority during this summer, is to get a second paper ready. I have been working on it now rather intensively and I think it is coming together quite nicely. So far the analysis has been theoretical, which is a nice change from a mainly empirical and numerical analysis carried out in previous paper. However, the next step is to include leaching functions for nitrogen and phosphorus into the numerical analysis. Therefore the scope is wider in this paper since it will discuss agricultural and environmental aspects via bio-economic modelling. As such the second paper will most likely be easier to sell to journal (compared to the first paper). But, it remains to be seen.
Meanwhile, we still wait for the summer to start here in Finland.
See you next time,
Best regards: Matti Sihvonen
18.05.2017 10:42Full of the joys of spring and springs (Storm in a teacup - water is everywhere BONUS SOILS2SEA)
In the fieldwork the most important is ... smile, thermos and Occupational Health and Safety :)
15.05.2017 16:20BONUS BaltCoast Summer School 2017: Call for applications is now open! (BONUS BALTCOAST blog)
This is the 2nd Summer School organized by BONUS BaltCoast project and after a successful run in 2016 at Klaipeda University (Lithuania) it will take place now in Latvia, coordinated by University of Latvia.
06.05.2017 11:01Equipment explained- part III: the t-brush (Sources & Sinks: A Tale of Coastal Biogeochemistry - BONUS COCOA)
Last time in EE II you learned all about soft sediment coring with a GEMINI/GEMAX corer. Muddy soft sediments are generally sticky, often stinky, and sampling them will most likely make you look like a little piglet that enjoyed a decent roll in its favorite pit. That´s why we wrap us in orange rubber and simply accept the mud stains on everything uncovered, such as… the face.
A bucket full of black mud from the seafloor. Everything not in the bucket can be found on Anni and me, though the picture shows a rather clean state of us (pictures: Ines Bartl, IOW).
But what about the core sleeves that hold our samples, what degree of mud stain is acceptable there?
Very simple: none.
One of the most crucial points in getting reliable data are undisturbed and uncontaminated samples. When working with sediment, a fast track to destroy your sample directly onboard is to get sediments from deeper layers onto the top surface and the water overlying the surface, mixing totally different element compositions and concentrations.
This points a big finger to constant cleaning: fingers, top lids, sub sampling gear and the core sleeves. And with a sleeve diameter of 8-9 cm which tool would be better suited for that job than a t(oilet) brush?Clean core sleeves thanks to lots of water and a t(oilet) brush (picture: Franziska Thoms, IOW).
totally serious about this: a toilet brush is one of the essential key tools in
And so romantic in the sunset (picture: Franziska Thoms, IOW).
03.05.2017 12:19Being the last and the first at the same time... (Benthosphere - BONUS COCOA)
Our project-colleague Halina Kendzierska from the University of Gdańsk has defended her PhD thesis and tells us about her experiences. Congratulations and The Benthosphare wish you all the best in your future projects!
14.04.2017 11:50The lost art of writing (and speaking) (BONUS BALTICAPP - Race Against Eutrophication Blog)
Things have been moving quite nicely in recent times. First of all, we got the first article ready and it’s now submitted to a journal. I must say that it was rather challenge for me. The actual writing process proved to be very difficult in the end. I had some real difficulties to put a discussion, conclusions and abstract sections together. This may be due to the fact that we, students in economics, can graduate with surprisingly little amount of reading and writing, since most of our focus is on the mathematical side of things. Most of my studies were about formulating optimization problems and solving them mathematically. Typically the exams required no excessive amount of reading, whereas the problem sets and mathematical examples are important to learn. As a result, one can graduate with flying colors without being very impressive writer (or reader).
Anyway, I participated a scientific writing course, which turned out to be very helpful at this point. Only now have I really started to understand how important it is to actually learn to clearly express your ideas. I think that in mathematically oriented fields it’s rather common to ignore the importance of writing skills. One learns the true value of such skills just when one really needs to publish something. In addition to scientific writing course, I also attended a statistic modelling with R course. This course has also been a very informative one and I’ve learned a lot of important things. I think that statistical modelling is a next step from the basics of statistics. It has also been a very nice course for me because it takes a more practical approach as it focuses on examining the models through examples that are solved with R. In addition, the course is an online course and all the lectures are just in Internet. In addition to theses courses, we have the PhD level course “Economic growth and environmental resources”, which is basically a macroeconomics course. We have to hand in the exercise sets by the end of this month. There require a lot of attention and it’s hard work because I’m not familiar with macroeconomic models. Nevertheless, I’m familiar with the dynamic optimization, which appears to be a primary tool in solving the macroeconomic problems. Therefore the course is very useful for me, because I have to keep practicing all kinds of dynamic analyses. It’s also good to get basic understanding of the most important macro models although I wouldn’t ever do macroeconomic analysis within my work.
We also had a project meeting Stockholm. I gave a presentation of our paper there. I thought it went better than my previous presentations since my English speaking has improved quite a bit since I started and also because the work is now ready. Despite of those improvements, I was still very nervous and I talked very quickly so that no one could interrupt me. As a result, my presentation was too difficult to follow at that point of a day; I realized that I used only abbreviation of the soil phosphorus and I didn’t explain it at any point during the presentation. Thus, I may have lost the audience right in the beginning. Thus, the take-home-message from Stockholm is that I must learn to give clearer and simpler presentations in the future. This will be particularly important, because the paper of ours got accepted to EAERE (European annual environmental and resource economics) 2017 conference. This was very good news and it made me very happy. The conference will be held in Greece (I have never been so far a way from home before). Thus, it will be exciting both professionally and also as an adventure. I look forward to it. At the mean time, I must learn the art of giving presentations. In addition, I must make really rabid progress with the second paper, if I want to graduate in time. Thus, the spring and the summer will be busy, but also exciting time.
See you next time!
Best regards: Matti Sihvonen
01.04.2017 17:56Equipment explained: part II - the GEMAX / GEMINI corer (Sources & Sinks: A Tale of Coastal Biogeochemistry - BONUS COCOA)
Yet, with increasing water depth and subsequently decreasing light, sampling via diving becomes complicated. On the dark side of the sea floor we therefore use sediment corers operated from ships. As corers have no eyes, we work virtually blindfolded which can often feel like gambling (and thus holds a certain kick). Sediment maps are helpful for giving directions, especially in early planning phases; however, often they are extrapolated or outdated and when looking at the first sample coming on deck, you might find that the sediment type has changed over the years, e.g. due to a change of current regime or deposition environment.
Surprises for free, excitement guaranteed- that´s sediment coring!
retrieval of a sediment sample from the sea floor depends largely on the right
corer. Sediment types vary in sturdiness, resp. softness, e.g. comparing sturdy
sand sediment with soft mud sediment; consequently, you have special corers for
each type. If you have followed this blog for some time, you will have heard
about MUC, HAPS, GEMAX, GEMINI, BOX – over the last 3 years, we have had them
Today you will meet the GEMAX/GEMINI corer, which is according to an essay by Boris Winterhalter the “ultimate corer for soft sediment”. Do I need to say more?
The GEMAX /
GEMINI corers are twin gravity corers for soft sediments. They base on the
original Niemistö corer (Niemistö, 1974), which was highly successful with the
only offset of a too small sample size. By doubling the core barrels a twin
corer was born, self-evidently baptized GEMINI. Sample quality was further improved
by increasing the diameter of the core barrels, which created the GEMAX.
Today, both GEMINI and GEMAX are standard corers all along the Baltic Sea coast. They consist of a stainless steel housing which is fitted by acryl core liners with sharpened steel cutters at their ends; those, as the name says, are capable to cut through the sediment. In the end, the core liners will hold the sediment sample. Both corers might look alike, but do not underestimate their difference: even 1 cm variation in core diameter makes a huge difference when trying to fit in a wrong inner core liner. From experience I can say: no, they don´t fit and no, they also cannot be squeezed in. Acryl is a quite solid material.
The corer penetrates soft sediments vertically based on its own weight and the lowering speed of the winch. Upon upwards pull a closing mechanism is triggered that locks the sediment securely in the core liners, creating a nice sediment core of ~ 30-40 cm.
And action: Laetitia, Wytze and Mathias while retrieving the full core liners. Requirements here: be quick, put the plug tight and don´t be afraid of getting muddy (left). My house, my car, my....sediment core: happy mood while subsampling a fresh core (right). (pictures: Ines Bartl, IOW)
Some care needs to be taken for the core liners, which somehow have a tendency to roll over board. Your only solution if you want to have them back: diving- and the circle closes.
Next time in equipment explained: why a toilet brush is an essential tool in sediment coring.
28.02.2017 18:16How stakeholders help to bring results to perfection – Or: One step back, two steps forward. (MIRACLE)
The 4th workshop in Germany, one of the four case study areas of the MIRACLE project, was held on 24th February 2017. Project members and various stakeholders, such as members of farming unions and governmental representatives with an agricultural, environmental or water management background gathered in Magdeburg, Germany, to continue the discussions about various issues connected to the project's aims and subjects.
Besides of following up on the last workshop, discussing the updated hydro-modelling results, and looking at the way forward, a major part of the meeting took the presentation, discussion and verification of the cost structures of the different measures, and the preliminary Cost-Benefit Analysis (CBA) results. Stakeholders could for instance verify “our” average gross margin in the Selke river area (can be used as an estimate of farmers’ lost income due to implementing a certain measure), or our approach to define “contour ploughing” as cost-neutral. Other potential measures were identified as redundant, e.g. due to being implemented anyway, or due to being no longer supported by the CAP in this specific area. Furthermore, stakeholders offered to provide more specific cost data of some very specific measures (such as the “ventilation and treatment of mine water and mine water retention” or the “dismantling of transverse structures”).
While the CBA results are still broad and based on many assumptions, every stakeholder verification, comment or correction makes it possible to fill more and more gaps, and therefore generate results closer to reality - one step back, two steps forward.
26.02.2017 14:11Equipment explained: part I – the scientific knitting needles (Sources & Sinks: A Tale of Coastal Biogeochemistry - BONUS COCOA)
While writing up the materials & methods part of my work, I came to realize how often ordinary household items find a permanent place in the scientific tool box. So far, during field and lab work I have been using tooth picks, pressure cookers, flip-top beer bottles, knitting needles, toilet brushes and not to forget the number one all-purpose item, the bucket (water sampler, sample and waste container, water bath and chair all at once) – all for scientific purposes.
Yes, this is scientific equipment: flip-top beer bottles used for salinity sample storage (advantage: tight closing), a cup as support item, and two household pressure cookers used as autoclaves, e.g. for divers biogeochemical analysis.
In this new series you will get to know everything you ever wanted to know about our equipment – ALL our equipment.
Part 1: the scientific knitting needles
When measuring sediment denitrification, I add isotopically labeled nitrate (15NO3-) to intact sediment cores. This nitrate will be reduced by the denitrifying bacteria to as well labeled N2, from which the genuine denitrification rate can be calculated (a very rough and simplified description of the isotope pairing technique, Nielsen 1992). To stop the process after a certain incubation time, I carefully mix the sediment, create a sediment-water slurry and thus stop the anaerobic reaction by introducing oxygen.
Mixing a soft, muddy sediment is easy:
Mixing a coarse
sandy sediment is somewhat more challenging, as it is usually compact, sturdy
and thus utterly unwilling to be mixed:
That´s how the knitting needles found
their place in my sand work equipment: being similarly sturdy, sharpened
and slim, they proved to be the perfect tool for creating a careful sand-water
slurry. Beyond that, if you should have time off during your incubation waiting time...na, kidding. There´s no time off. Never :-)
Next time in "equipment explained": the Gemini / Gemax twin corer!
20.02.2017 14:01One-way ticket from Matlab to R, and back! (BONUS BALTICAPP - Race Against Eutrophication Blog)
Hi everybody!I’ve decided to write this somewhat monthly blog post in somewhat more technical fashion compared to my previous posts, which are written in very general fashion. The methods that I’ve been using so far in writing my first two articles have been non-linear weighted OLS estimation and dynamic programming. I’ve used Matlab for both of these. Matlab is a great program for many things, particularly optimizing, as far as my experiences are considered. However, I’ve started to question the reliability of the estimation results that Matlab provides. In addition, I haven’t been able to get all the statistics that I would need for the proper analysis. These statistics include the basics standard errors, t-values and p-values for the estimates. I also can’t reproduce the goodness-of-fit statistics by basics calculations myself. I noticed that the 95 % confidence intervals that Matlab gives for the estimated parameters are very wide. Those even go beyond the range were the function is determined, which I found very suspicious. Thus, I turned to R, which is very much-applied program for statistical analysis. I learned to do the weighted non-linear estimation in R and I finally got all the statistics that I needed. In addition, I understand the statistics it provides and there’s nothing mysterious going on, which I found very important when the actual research work is considered; one has to know where all the numbers have come from.
to say, I had to reconsider some models and results. However, although I found
R more suitable for statistical analysis than Matlab, the issue with non-linear
estimation in R is the starting values for the estimates. It seems that those
have to be very close to final values so that the program will be able to do the fitting. So
how do you get to those starting values? I used Matlab for those. Matlab’s
curve fitting toolbox, although I don’t trust in the statistics it provides, is
very useful, as it illustrates the curve and the residuals right away. It also
is very successful in fitting the curve or surface even with the default starting
values, once the iteration account is set high enough. This might be related to
Matlab’s good optimization abilities, as it is matrix-based program, and
estimation is optimization, after all. Thus, I used Matlab for initial
examination for a particular functional form and to get the starting values.
Then I inserted the functional form and the starting values into R to get the
final estimates for the parameters as well as the associated statistics. Then I
used Matlab again for drawing illustrative simulation figures and for the economic
optimization. I must say that for those purposes the Matlab is superior
compared to R, at least as far as my very limited programming skills are
considered. All the figures in my work are drawn with Matlab, with the
exception of one schematic diagram.
now that I’ve been shifting back and forth between Matlab and R a couple of
weeks, I believe that the first article is finally ready and it’s time to
continue the work with the second article, which focuses entirely on
optimization. In first work we
concentrated on model derivation and examination of the structural and
parameter uncertainty. In the next paper we will examine analytically and
numerically the private optimums a bit further and then we move to examine the
social optimum, where also the environmental externalities are considered. I
will write more about those in the upcoming blog posts. I guess my main tool when doing the second article will be Matlab again, because at least currently is seems that no statistical analysis will be involved.
Thus, see you next time!
Best regards: Matti Sihvonen
14.02.2017 11:39BONUS BaltCoast 2nd Stakeholder Meeting (BONUS BALTCOAST blog)
The Second BONUS BaltCoast project Stakeholder meeting was held on the 7th of February 2017, at Nida Art Colony (Taikos str. 43, Nida, Lithuania) to discuss the issue of opening a new bathing place in the Curonian Lagoon at Nida. Stakeholders were pleasantly surprised by our accomplishments and have expressed gratitude, because our studies will benefit the decision making process greatly.