• Environmental and Resource Economics Review
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• v.23 no.2
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• pp.187-224
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• 2014

We present key issues to consider in estimating damages from price-fixing cases and then apply the procedure addressing those issues to a transportation fuel market. Among the five methods of overcharge calculation, the regression analysis incorporating the yardstick method is the best. If the price equation relates the domestic price to the foreign price and the exchange rate as in the transportation fuel market, the functional form satisfying both logical consistency and modeling flexibility is the log-log functional form. If the data under analysis is of time series in nature, then the ARDL model should be the base model for each market and the regression analysis incorporating the yardstick method combines these ARDL equations to account for inter-market correlation and arrange constant terms and collusion-period dummies across component equations appropriately so as to identify the overcharge parameter. We propose a two-step test for the benchmarked market: (a) conduct market-by-market Spearman or Kendall test for randomness of the individual market price series first and (b) then conduct across-market Friedman test for homogeneity of the market price series. Statistical significance is the minimal requirement to establish the alleged proposition in the world of uncertainty. Between the sensitivity analysis and the model selection process for the best fitting model, the latter is far more important in the economic analysis of damage in price-fixing litigation. We applied our framework to a transportation fuel market and could not reject the null hypothesis of no overcharge.

• Korean Journal of Agricultural and Forest Meteorology
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• v.17 no.3
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• pp.191-201
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• 2015

Measuring and mapping connectivity among habitats is a key component of sustainable urban planning and design process. In this study, we examined how functional corridors connect forest bird habitats in a metropolitan area of Korea using graph theory-based techniques. High-quality forest habitat was defined as a function of forest cover, presence of residential areas, and road networks. We then constructed a network of high-quality forest habitats using the FunConn (functional connectivity) tools, and computed metrics ($T_i$) of patch importance based on the minimum ($Q_1$) and the 25th percentile ($Q_{25}$) rank least-cost distance values. We investigated the relative influence of two values of patch importance on forest bird species richness. As a result, the patch importance index based on the $Q_{25}$ effective distance threshold was most positively correlated with species richness (P < 0.001) after controlling for the area effect. Thus, using the $Q_{25}$ effective distance threshold, we mapped not only the locations of important habitat patches and functional corridors, but also the network backbone of forest bird habitats. The network developed in this study can help guide urban planning for biodiversity conservation.

• Korean Journal of Food Science and Technology
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• v.43 no.4
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• pp.469-474
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• 2011

Ginger (Zingiber officinale Rosc.) is a well known edible plant that is traditionally used to treat various illnesses related to inflammation and oxidative stress. Steam distillated ginger oil or water extract are mainly used for related products; however, it is unclear whether these fractions contain most of the bioactive compounds or the highest efficacy. This investigated the antioxidant effects of extracts prepared by supercritical fluid extraction (SFE). 6-Gingerol was the most abundant component in hexane fraction of ethanol extract from ginger. The antioxidative properties of SFE oil and Marc ethanol fractions were demonstrated using the 2,20-diphenylpicrylhydrazyl (DPPH) and 2,2'-azinobis 3-ethyl benzothiazoline-6-sulfonic acid (ABTS) radicals scavenging assays. A clear correlation was observed between total polyphenol contents and $RC_{50}$ values in the Marc ethanol fraction. These results indicate that not only SFE oil but the marc after SFE could be good sources for the food industry.

• Korean Journal of Clinical Laboratory Science
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• v.52 no.1
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• pp.1-17
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• 2020

Three-dimensional microscopic approaches in histopathology display multiplex properties that present puzzling questions for specimens as related to their comprehensive volumetric information. This information includes spatial distribution of molecules, three-dimensional co-localization, structural formation and whole data set that cannot be determined by two-dimensional section slides due to the inevitable loss of spatial information. Advancement of optical instruments such as two-photon microscopy and high performance objectives with motorized correction collars have narrowed the gap between optical theories and the actual reality of deep tissue imaging. However, the benefits gained by a prolonged working distance, two-photon laser and optimized beam alignment are inevitably diminished because of the light scattering phenomenon that is deeply related to the refractive index mismatch between each cellular component and the surrounding medium. From the first approaches with simple crude refractive index matching techniques to the recent cutting-edge integrated tissue clearing methods, an achievement of transparency without morphological denaturation and eradication of natural and fixation-induced nonspecific autofluorescence out of real signal are key factors to determine the perfection of tissue clearing and the immunofluorescent staining for high contrast images. When performing integrated laboratory workflow of tissue for processing frozen and formalin-fixed tissues, clear lipid-exchanged acrylamide-hybridized rigid imaging/immunostaining/in situ hybridization-compatible tissue hydrogel (CLARITY), an equipment-based tissue clearing method, is compatible with routine procedures in a histopathology laboratory.

• Journal of KIISE:Software and Applications
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• v.33 no.2
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• pp.201-219
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• 2006

The key to developing software with the lowest cost and highest quality is to implement or fit the software development process into a given environment. Generally, applying commercial or standard software development processes on a specific project can cause too much overhead if there is no effort to customize the given generic processes. Even though the customizing activities are done before starting the project, these activities are thoroughly dependent on the process engineers who have abundant experience and knowledge with tailoring processes. Owing to this dependence on human knowledge, it has been very difficult to explain the rationale for the results of process tailoring and it takes a long time to get the customized process that is applicable. Hence, we suggest a process tailoring method which adopts the artificial neural network based teaming theory to reduce the time consumed by process tailoring. Furthermore, we suggest the feedback loop mechanism to get higher accuracy in the neural network designed for the process tailoring. It can be done by reusing the process tailoring data results and determining its appropriateness level as sample data to the neural network. We proved the effectiveness of our process tailoring method through case studies using real historical data, which yielded abundant process tailoring results as sample data.

• The Journal of Society for e-Business Studies
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• v.13 no.2
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• pp.56-82
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• 2008

The topic on Flow is generating increased interests in e-commerce studies. Flow has been identified as a key component in e-commerce. Studies on Flow have so far focused on internet shopping mall, but scarcely looked at the Flow of Internet auction. The purpose of study is to find out which factors play a major role in building Flow on internet auction and how the built-up Flow affect Brand Equity. Therefore, the research model investigates what factors influence Flow. Furthermore, the research is designed to understand how the Flow influences Brand Equity. The antecedents of Flow classifies into three types such as personal (Challenge, Skill), IT characteristic, Internet Auction characteristic. The results of this empirical study shows that three characteristics significantly affected the flow：personal (Challenge), IT (information quality, system quality), and Internet Auction (interactivity). And also Flow has significant effect on the brand equity. This result indicates that customer's optimal experience is important to increase brand equity. That is, the flow is influenced by multi-dimensional factors and plays an important role in increasing brand equity. Finally, the finding of this study suggests that personal challenge, information quality, system quality, and interactivity should be enhanced preferentially.

• Journal of the Korea Society of Computer and Information
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• v.5 no.4
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• pp.41-47
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• 2000

In modern dynamic management environment, there is growing recognition that information & knowledge management systems are essential for CEO's efficient/effective decision making. As a key component to cope with this current, we suggest the management performance data-mining system based on IT(Information Technology). This system measures management performance that is considered with both VA(Value-Added), which represents stakeholder's point of view and EVA(Economic Value-Added), which represents shareholder's point of view. The relationship between management performance and 85 financial ratios is analyzed, and then important financial ratios are drawn out. In analyzing the relationship, we applied the explanation-based Gas(Genetic Algorithms) that consider predictability, understanability (lucidity) and reasonability factors simultaneously. To demonstrate the performance of the system, we conducted a case study using financial data over the 16-years from 1981 to 1996 of Korean automobile industry which is taken from database of KISFAS(Korea Investors Services Financial Analysis System).

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.9
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• pp.1515-1521
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• 2004

As one of the research series for the industrialization of sikhae, this study was evaluated the taste compounds present in different temperature conditions, $5^{\circ}C$, $20^{\circ}C$ and alternating temperature (stored at $5^{\circ}C$ after 10 days fermentation at $20^{\circ}C$), respectively. The changes in proximate compositions were negligible but the amounts of total sugar decreased during fermentation. The pH of sikhae products except the product fermented at $5^{\circ}C$, decreased during fermentation and was maintained at the rage of 3.8~4.4 after 10 days. The values of acidity, VBN and amino-N gradually increased with fermentation times and with increasing temperature condition in all products. Three organic acids (lactic, citric and malic acid) were disclosed as key compounds affecting the sourness in Alaska pollack sikhae. The result of taste value revealed that 6 amino acids having sweet and umami taste (aspartic acid, glutamic acid, alanine and lysine) and bitter taste (valine and methionine) as major amino acids affecting the taste of sikhae products, and increased with fermentation times. Hypoxanthine was the main component in ATP related compounds. Amino-N was comprised more over 50% of the Ex-N in sikhae products, and followed by total creatinine-N, TMAO-N and TMA-N in that order.

• Journal of The Korean Society of Agricultural Engineers
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• v.59 no.1
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• pp.81-96
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• 2017

Along with climate change, it is reported that the scale and the frequency of extreme climate events (e.g. heavy rain, typhoon, etc.) show unstable tendency of increase. In case of Korea, also, the frequency of heavy rainfall shows increasing tendency, thus causing natural disaster damage in downtown and agricultural areas by rainfall that exceeds the design criteria of hydraulic structures. In order to minimize natural disaster damage, it is necessary to analyze how extreme precipitation event changes under climate change. Therefore a new design criteria based on non-stationarity frequency analysis is needed to consider a tendency of future extreme precipitation event and to prepare countermeasures to climate change. And a quantitative and objective characteristic analysis could be a key to preparing countermeasures to climate change impact. In this study, non-stationarity frequency analysis was performed and inundation risk indices developed by 4 inundation characteristics (e.g. inundation area, inundation depth, inundation duration, and inundation radius) were assessed. The study results showed that future probable rainfall could exceed the existing design criteria of hydraulic structures (rivers of state: 100yr-200yr, river banks: 50yr-100yr) reaching over 500yr frequency probable rainfall of the past. Inundation characteristics showed higher value in the future compared to the past, especially in sections with tributary stream inflow. Also, the inundation risk indices were estimated as 0.14 for the past period of 1973-2015, and 0.25, 0.29, 1.27 for the future period of 2016-2040, 2041-2070, 2071-2100, respectively. The study findings are expected to be used as a basis to analyze future inundation damage and to establish management solutions for rivers with inundation risks.

• Journal of the Institute of Convergence Signal Processing
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• v.5 no.4
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• pp.256-262
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• 2004

A key component of an autonomous mobile robot is to localize itself and build a map of the environment simultaneously. In this paper, we propose a vision-based localization and mapping algorithm of mobile robot using fisheye lens. To acquire high-level features with scale invariance, a camera with fisheye lens facing toward to ceiling is attached to the robot. These features are used in mP building and localization. As a preprocessing, input image from fisheye lens is calibrated to remove radial distortion and then labeling and convex hull techniques are used to segment ceiling and wall region for the calibrated image. At the initial map building process, features we calculated for each segmented region and stored in map database. Features are continuously calculated for sequential input images and matched to the map. n some features are not matched, those features are added to the map. This map matching and updating process is continued until map building process is finished, Localization is used in map building process and searching the location of the robot on the map. The calculated features at the position of the robot are matched to the existing map to estimate the real position of the robot, and map building database is updated at the same time. By the proposed method, the elapsed time for map building is within 2 minutes for 50㎡ region, the positioning accuracy is ±13cm and the error about the positioning angle of the robot is ±3 degree for localization.