• Environmental and Resource Economics Review
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• v.27 no.3
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• pp.569-611
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• 2018

Rapid economic growth, urbanization, and industrialization of China have tremendously degraded the overall quality of living environments, especially the air quality, not only negatively affecting Chinese people but also impacting citizens of neighboring countries, namely Korea. The Chinese government has invested much effort to regulate the air pollution due to burning coal through introducing strict environmental monitoring policies and aggressive implementation. This paper presents an overview of Chinese air pollution prevention policy due to burning coal, and the associated trends and specifics of institutional arrangements regarding air pollutant emission regulations. It turns out that the policies have become stricter than before; some polices are geared towards enforcing extra regulation at the regional level. It is expected that the regulation will become stricter in the future. However, the actual contribution and feasibility of such policies must be analyzed based on sound science. The policies seem to care little about influencing the air quality of Korea, and this has to be improved. In order to do so, it is important to strengthen environmental cooperation between Korea and China, and better yet to research on not only the air quality but also the associated fields, such as energy, industrial technology, and global environmental governance.

• Journal of Energy Engineering
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• v.16 no.4
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• pp.170-180
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• 2007

This paper deals with the economy of scale for domestic on-site hydrogen stations fueled with natural gas and naptha. We evaluate the economic feasibility of on-site hydrogen stations with hydrogen production capacities of $30Nm^3/hr,\;100Nm^3/hr\;and\;300Nm^3/hr$. We build a classical economic feasibility model and we make some sensitivity analyses by changing the values of input factors such as the hydrogen sale price and the discount rate. The estimated hydrogen prices of steam methane reforming stations with production capacities of $30\;Nm^3/hr,\;100\;Nm^3/hr\;and\;300\;Nm^3/hr$ are 18,472 won/kg, 10,689 won/kg and 7,758 won/kg, respectively. Also, the hydrogen prices are about the same if we use naptha as a raw material for hydrogen energy instead of natural gas. It turns out that small and medium size domestic on-site hydrogen stations will not be economical in the near future. This indicates that we need to construct large scale on-site hydrogen fueling stations even for the initial phase of the hydrogen economy.

• Journal of Energy Engineering
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• v.23 no.2
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• pp.102-113
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• 2014

This study analyzes whether the value-added structure of Korean bioenergy industry exhibits a virtuous cycle through the value chain(VC) within bioenergy firms, using a regression analysis based on a survey to Korean bioenergy companies. As a result, in Korean bioenergy companies, the R&D outputs positively influence an increase in production, and a decrease in production costs positively influences an increase in profit rates per sales. However, the government's supports for R&D is analyzed neither to lead an increase in corporates' R&D investments, nor to contribute to an increase in their R&D outputs. In addition, it turns out that an increase in production does not contribute to a decrease in production costs. Besides, it is analyzed that an increase in profit rates per sales does not contribute to an increase in production or an increase in the R&D investments. The virtuous cycle of the value chain in Korean bioenergy firms is, therefore, estimated to be weak. This study has a policy implication to need further efforts to create the virtuous cycle in the VC of Korean bioenergy industry.

• Journal of Elementary Mathematics Education in Korea
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• v.12 no.1
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• pp.79-100
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• 2008

Freudenthal has advocated the reinvention method. In that method, the pupils start with a meaningful context, not ready-made concepts, and invent informative method through which he could arrive at the formative concepts progressively. In many face the reinvention method is contrary to the traditional method. In traditional method, which was named as 'concretization method' by Freudenthal, the pupils start with ready-made concepts, and applicate this concepts to various instances through which he could arrive at the understanding progressively. Through analysis, it turns out that Korea's seventh elementary mathematics textbook is based on concretization method. In this thesis, first of all, I will reconstruct probability unit of seventh elementary textbook according to Freudenthal's reinvention method. Next, I will perform teaching experiment which is ruled by new lesson design. Lastly, I analysed the effects of teaching experiment. Through this study, I obtained the following results and suggestions. First, the reinvention method is effective on the teaching of probability concept and algorithm. Second, in comparison with current textbook strand, my strand which made probability concept go ahead and combinatorics concept let behind is not deficiency. Third, tree diagram is effective matrix which contribute to formalization of combinatorics calculation. Lastly, except for fraction, diverse representation of probability, for example percentage or informal ratio expression must be introduced in teaching process.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.19 no.1
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• pp.81-96
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• 2007

Nonlinear shoaling characteristics over surf zone are numerically investigated based on spatially averaged NavierStokes equation. We also test the validity of gradient model for turbulent stresses due to wave breaking using the data acquainted during SUPERTANK LABORATORY DATA COLLECTION PROJECT(Krauss et al., 1992). It turns out that the characteristics length scale of breaking induced current is not negligible, which firmly stands against ever popular gradient model, ${\kappa}-{\varepsilon}$ model, but favors Large Eddy Simulation with finer grid. Based on these observations, we model the residual stress of spatially averaged NavierStokes equation after Lagrangian Dynamic Smagorinsky(Meneveau et al., 1996). We numerically integrate newly proposed wave equations using SPH with Gaussian kernel function. Severely deformed water surface profile, free falling water particle, queuing splash after landing of water particle on the free surface and wave finger due to structured vortex on rear side of wave crest(Narayanaswamy and Dalrymple, 2002) are successfully duplicated in the numerical simulation of wave propagation over uniform slope beach, which so far have been regarded very difficult features to mimic in the computational fluid mechanics.

• Archives of design research
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• v.17 no.3
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• pp.39-50
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• 2004

According to the survey done among the 20s of university students in Oct. 2002, the female animation characters from Korea and Japan have almost no distinction. Speaking of the features of the characters, they have big eyes, a long nose, an oval face. However, their eyes and mouths are expressed exaggeratedly, which makes them hard to get a good impression from the people. It seems that the identity of Korean female animation characters is disappearing in terms of the copycat from western animation characters. Through the research, the features of 20s of Korean and Japanese girls are compared and they were reviewed from the ideal and biological point of view. Then, the animation characters, which physiognomy has been applied, are created based on result, which I am trying to find the standard model of Korea female animation character. As an ideal point of view, it turns out that Korean has a positive reaction on the female animation characters with the cute & introspective characteristics. On the contrary, Korean has a negative reactions on the ones that were created in a biological viewpoint and has a highly sensitive and discontented characteristics. This shows that Korean do not prefer the female animation characters with highly sensitive and discontented characters. According to the survey, 73.5% of people could find the same 7 kinds of female characters which are shown frequently in the animation. This means that the oriental physiognomy is an effective way to approach to the features of the character's face depending on the characteristics of each female characters. The characters in this study are based on real face of female, but we can create the various animation characters if we apply the partial feature of distinctive each personal face.

• Magazine of the Korean Society of Agricultural Engineers
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• v.26 no.4
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• pp.52-65
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• 1984

In general precise estimation of hourly of daily distribution of the long-term run-off should be very important in a design of source of irrigation. However, there have not been a satisfying method for forecasting of stationar'y long-term run-off in Korea. Solving this problem, this study introduces unit-hydrograph method frequently used in short-term run-off analysis into the long-term run-off analysis, of which model basin was selected to be Sumgin-river catchment area. In the estimation of effective rainfall, conventional method neglects the Soil moisture condition of catchment area, but in this study, the initial discharge (qb) occurred just before rising phase of the hydrograph was selected as the index of a basin soil moisture condition and then introduced as 3rd variable in the analysis of the reationship between cumulative rainfall and cumulative loss of rainfall, which built a new type of separation method of effective rainfall. In next step, in order to normalize significant potential error included in hydrological data, especially in vast catchment area, Snyder's correlation method was applied. A key to solution in this study is multiple correlation method or multiple regressional analysis, which is primarily based on the method of least squres and which is solved by the form of systems of linear equations. And for verification of the change of characteristics of unit hydrograph according to the variation of a various kind of hydrological charateristics (for example, precipitation, tree cover, soil condition, etc),seasonal unit hydrograph models of dry season(autumn, winter), semi-dry season (spring), rainy season (summer) were made respectively. The results obtained in this study were summarized as follows; 1.During the test period of 1966-1971, effective rainfall was estimated for the total 114 run-off hydrograph. From this estimation results, relative error of estimation to the ovservation value was 6%, -which is mush smaller than 12% of the error of conventional method. 2.During the test period, daily distribution of long-term run-off discharge was estimated by the unit hydrograph model. From this estimation results, relative error of estimation by the application of standard unit hydrograph model was 12%. When estimating by each seasonal unit bydrograph model, the relative error was 14% during dry season 10% during semi-dry season and 7% during rainy season, which is much smaller than 37% of conventional method. Summing up the analysis results obtained above, it is convinced that qb-index method of this study for the estimation of effective rainfall be preciser than any other method developed before. Because even recently no method has been developed for the estimation of daily distribution of long-term run-off dicharge, therefore estimation value by unit hydrograph model was only compared with that due to kaziyama method which estimates monthly run-off discharge. However this method due to this study turns out to have high accuracy. If specially mentioned from the results of this study, there is no need to use each seasonal unit hydrograph model separately except the case of semi-dry season. The author hopes to analyze the latter case in future sudies.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.8A
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• pp.739-752
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• 2002

Recently, to utilize the limited bandwidth effectively, the concept of partial response (PR) signaling has widely been adopted in both the high-speed data transmission and high-density digital recording/playback systems such as digital microwave, digital subscriber loops, hard disk drives, digital VCR's and digital versatile recordable disks and so on. This paper is concerned with adaptive equalization of partial response channels particularly for the magnetic recording channels. Specifically we study how the PR channel equalizers work for different choices of desired or reference signals used for adjusting the equalizer weights. In doing so, we consider three different configurations that are actually implemented in the commercial products mentioned above. First of all, we show how to compute the theoretical values of the optimum Wiener solutions derived by minimizing the mean-squared error (MSE) at the equalizer output. Noting that this equalizer MSE measure cannot be used to fairly compare the three configurations, we propose to use the data MSE that is computer just before the final detector for the underlying PR system. We also express the data MSE in terms of the channel impulse response values, source data power and additive noise power, thereby making it possible to compare the performance of the configurations under study. The results of extensive computer simulation indicate that our theoretical derivation is correct with high precision. Comparing the three configurations, it also turns out that one of the three configurations needs to be further improved in performance although it has an apparent advantage over the others in terms of memory size when implemented using RAM's for the decision feedback part.

• International Journal of Highway Engineering
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• v.9 no.3
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• pp.1-12
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• 2007

Roads in Korea can be classified into four types according to their responsible authorities. For example, Motorway is constructed, managed, and operated by the Korea Highway Corporation. Ministry of Construction and Transportation is in charge of National Highway, and Province Roads are run by each province government. Urban/county Roads are run by corresponding local government. This study analyses the trends of road accidents for each road type. For this purpose, the numbers of accidents, fatalities, and injuries are compared for each road type for last 15 years. The result shows that Urban/County Roads are the most dangerous, while Motorways are the safest, when we simply compare the numbers of accidents, fatalities, and injuries. However, when we compare these numbers by dividing by total road length, National Highway becomes the most dangerous while Province Roads becomes the safest. In the case of road accidents, fatalities, and injuries per vehicle km, which is known as the most objective comparison measure, it turns out that National Highway is the most dangerous roads again. This study also developed time series models to estimate trends of fatalities for each road type. These models will be useful when we set up or evaluate targets of national road safety.

• Journal of Korean Society of Transportation
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• v.28 no.5
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• pp.17-29
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• 2010

The main objective of this study is to consider the necessity of introducing owner expenses in estimating the cost of traffic accidents, as is done in some advanced countries. It is known as "owner cost" in the U.S, "enterprise project price" in Japan, and "human cost" in the U.K. To achieve this, the seriousness and present state of post-traumatic stress disorder (PTSD) of traffic accident offenders, which is generally not observed when traffic accidents occur, are evaluated; countermeasures reflecting personal characteristics are prepared according to degree of affliction. The results could be summarized as follows. First, the present condition and seriousness of PTSD from traffic accidents that has been estimated only within the accidents offenders are evaluated through a survey. Second, a distinction analysis model is developed. 'Insomnia caused by accidents' and 'mental daunting in accident situations or similar ones during driving' are chosen as the variables of the discriminant. Third, as a result of the construction of an Ordered Probit Model to comprehend the seriousness of PTSD, the variables turns out in the order of 'seriousness of the most damaged victim, 'nightmare about the accident', 'insomnia experience', 'mental daunting during driving', 'gender', and 'major driving area'. Finally, the cures reflecting characteristics of gender and region are suggested, which are preferred for degree of seriousness of PTSD. The analysis shows that the method to minimize the damage, such as decline of work efficiency, by moving ahead the rehabilitation of the offenders would be suggested and this could minimize the direct and indirect damages that could happen to business owners for whom the drivers work.