• Progress in Medical Physics
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• v.21 no.3
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• pp.304-310
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• 2010

Less execution of the electron arc treatment could in large part be attributed to the lack of an adequate planning system. Unlike most linear accelerators providing the electron arc mode, no commercial planning systems for the electron arc plan are available at this time. In this work, with the expectation that an easily accessible planning system could promote electron arc therapy, a commercial planning system was commissioned and evaluated for the electron arc plan. For the electron arc plan with use of a Varian 21-EX, Pinnacle3 (ver. 7.4f), with an electron pencil beam algorithm, was commissioned in which the arc consisted of multiple static fields with a fixed beam opening. Film dosimetry and point measurements were executed for the evaluation of the computation. Beam modeling was not satisfactory with the calculation of lateral profiles. Contrary to good agreement within 1% of the calculated and measured depth profiles, the calculated lateral profiles showed underestimation compared with measurements, such that the distance-to-agreement (DTA) was 5.1 mm at a 50% dose level for 6 MeV and 6.7 mm for 12 MeV with similar results for the measured depths. Point and film measurements for the humanoid phantom revealed that the delivered dose was more than the calculation by approximately 10%. The electron arc plan, based on the pencil beam algorithm, provides qualitative information for the dose distribution. Dose verification before the treatment should be mandatory.

• Microbiology and Biotechnology Letters
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• v.37 no.3
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• pp.248-257
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• 2009

The inhibitors against Vibrio harveyi quorum sensing (QS) signaling were developed by modifying the molecular structure of the major signal, N-3-hydroxybutanoyl-L-homoserine lactone (3-OH-$C_4$-HSL). A series of structural derivatives, N-(3-hydroxysulfonyl)-L-homoserine lactones (HSHLs) were synthesized by the solid-phase organic synthesis method. The in vivo QS inhibition by these compounds was measured by a bioassay system using the V. harveyi bioluminescence, and all showed significant inhibitory effects. To analyze the interaction between these compounds and LuxN, a 3-OH-$C_4$-HSL receptor protein of V. harveyi, we tentatively determined the putative signal binding domain of LuxN based on the sequence homology with other acyl-HSL binding proteins, and predicted the partial 3-D structure of the putative signal binding domain of LuxN by using ORCHESTRA program, and further estimated the binding poses and energies (docking scores) of 3-OH-$C_4$-HSL and HSHLs within the domain. In comparison of the result from this modeling study with that of in vivo bioassay, we suggest that the in silica interpretation of the interaction between ligands and their receptor proteins can be a valuable way to develop better competitive inhibitors, especially in the case that the structural information of the protein is limited.

• Journal of the Korean earth science society
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• v.28 no.1
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• pp.64-74
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• 2007

The marine seismic prospecting using a research vessel in the shallow sea near the coastal area has certain limits according to the water depth and survey environment. Also, for the electrical resistivity survey at seashore area, one may need a specially designed high-voltage source to penetrate the very conductive surface layer. Therefore, we have conducted a feasibility study on the application of magnetotelluric method (MT), a passive geophysical method, on investigating of shallow marine environment geology. Our study involves both theoretical modeling and field survey at the tidal flat area which represent the very shallow marine environment. We have applied the audio-frequency magnetotelluric (AMT) method to the intertidal deposits of Gunhung Bay, west coast of Korea, and analysed the field data both qualitatively and quantitatively to investigate the morphology and sedimentary stratigraphy of the tidal flat. The inversion of AMT data well reveals the upper sedimentary layer of Holocene intertidal sediments having a range of 13-20 m thickness and the erosional patterns at the unconformable contact boundary. However, the AMT inversion results tend to overestimate the depth of basement (30-50 m) when compared with the seismic section (27-33 m). Since MT responses are not significantly sensitive to the resistivity of middle layer or the depth of basement, the AMT inversion result for basement may have to be adjusted using the comparison with other geophysical information like seismic section or logging data if possible. But, the AMT method can be an effective alternative choice for investigating the seashore area to get important basic informations such as the depositional environment of the tidal flat, sea-water intrusion and the basement structure near the sea shore.

• Journal of forensic and investigative science
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• v.1 no.2
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• pp.5-19
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• 2006

Data mining is an information extraction activity to discover hidden facts contained in databases. Using a combination of machine learning, statistical analysis, modeling techniques and database technology, data mining finds patterns and subtle relationships in data and infers rules that allow the prediction of future results. Typical applications include market segmentation, customer profiling, fraud detection, evaluation of retail promotions, and credit risk analysis. Law enforcement agencies deal with mass data to investigate the crime and its amount is increasing due to the development of processing the data by using computer. Now new challenge to discover knowledge in that data is confronted to us. It can be applied in criminal investigation to find offenders by analysis of complex and relational data structures and free texts using their criminal records or statement texts. This study was aimed to evaluate possibile application of data mining and its limitation in practical criminal investigation. Clustering of the criminal cases will be possible in habitual crimes such as fraud and burglary when using data mining to identify the crime pattern. Neural network modelling, one of tools in data mining, can be applied to differentiating suspect's photograph or handwriting with that of convict or criminal profiling. A case study of in practical insurance fraud showed that data mining was useful in organized crimes such as gang, terrorism and money laundering. But the products of data mining in criminal investigation should be cautious for evaluating because data mining just offer a clue instead of conclusion. The legal regulation is needed to control the abuse of law enforcement agencies and to protect personal privacy or human rights.

• Journal of Distribution Research
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• v.15 no.1
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• pp.25-47
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• 2010

CS is one of the major concerns of managers in the world because it is well known to be a key medium construct for firms' superior outcome. One of the major agents for CS management is retailers. Firms try to manage not only employees but also retailers to promote CS behaviors. And so diverse incentives are used to promote their CS behaviors under diverse channel setting such as multi-channel. However in spite of the rising needs there has been scarce studies on the optimal incentive structure for a manufacturer to offer competing retailers at the multi-channel. In this paper, we try to find better way for a manufacturer to promote the competing retailers' CS behaviors. We investigated how to promote the retailers' CS behavior via game-theoretic modeling. Especially, we focus on the possible incentive, CS bonus type reward introduced in the studies of Hauser, Simester, and Wernerfelt(1994) and Chu and Desai(1995). We build up a multi stage complete information game and derive a subgame perfect equilibrium using backward induction. Stages of the game are as following. (Stage 1) Manufacturer sets wholesale price(w) and CS bonus($\eta$). (Stage 2) Both retailers in competition set CS effort level($e_i$) and retail price($p_i$) simultaneously. (Stage 3) Consumers make purchasing decisions based on the manufacturer's initial reputation and retailers' CS efforts.

• Knowledge Management Research
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• v.21 no.3
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• pp.249-269
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• 2020

Recently, as the online market has matured, it is facing many problems to prevent the growth. The most common problem is the homogenization of online products, which fails to increase the number of customers any more. Moreover, although the portion of the online market has increased significantly, it now becomes essential to expand offline for further development. In response, many online firms have recently sought to expand their businesses and marketing channels by securing offline spaces that can complement the limitations of online platforms, on top of their existing advantages of online channels. Based on their competitive advantage in terms of analyzing large volumes of customer data utilizing information technologies (e.g., big data and artificial intelligence), they are reinforcing their offline influence as well through this online for offline (O4O) business model. On the other hand, most of the existing research has primarily focused on online to offline (O2O) business model, and there is still a lack of research on O4O business models, which have been actively attempted in various industrial fields in recent years. Since a few of O4O-related studies have been conducted only in an experience marketing setting following a case study method, it is critical to conduct an empirical study on O4O selection attributes and their impact on customer satisfaction and loyalty. Therefore, focusing on China's representative O4O business model, 'Fresh Hema,' this study attempts to identify some key selection attributes specialized for O4O services from the customers' viewpoint and examine the impact of these attributes on customer satisfaction and loyalty. The results of the structural equation modeling (SEM) with 300 O4O (Fresh Hema) experienced customers, reveal that, out of seven O4O selection attributes, four (mobile app quality, mobile payment, product quality, and store facilities) have an impact on customer satisfaction, which also leads to customer loyalty (reuse intention, recommendation intention, and brand attachment). This study would help managers in an O4O area well adapt to rapidly changing customer needs and provide them with some guidelines for enhancing both customer satisfaction and loyalty by allocating more resources to more significant selection attributes, rather than less significant ones.

• Korean Journal of Agricultural and Forest Meteorology
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• v.20 no.2
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• pp.190-204
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• 2018

The probability of safe cropping and the major phenological stages in rice were assessed using daily mean temperature data from 1981 to 2016 at 27 sites in North Korea. The threshold temperatures for early marginal transplanting date (EMTD), marginal harvesting date (MHVD), safe marginal heading date (SMHD), and cumulative temperature-based heading date (CTHD) were set to be $14^{\circ}C$, $13^{\circ}C$, $22^{\circ}C$ for 40 days after heading, and cumulative temperature of $1200^{\circ}C$ to MHVD, respectively. The safe heading date (SHD) was assumed to be either SMHD or CTHD whichever was earlier. It was also assumed that the minimum requirement for the suitability of safe rice cropping was met when both SMHD and CTHD appeared along with the time period of 60 days or more from EMTD to SHD. It was analyzed that 17 sites (Kaesong, Haeju, Yongyon, Singye, Sariwon, Nampo, Pyongyang, Anju, Kusong, Sinuiju, Changjon, Wonsan, Hamhung, Pyonggang, Huichon, Supung, Kanggye) had 90% or higher probability, two sites (Yangdok, Sinpo) had 80-90% probability, and eight sites (Kimchaek, Chunggang, Chongjin, Sonbong, Changjin, Pungsan, Hyesan, Samjiyon) had less than 80% probability of the safe rice cropping. For each region, the representative EMTD, SHD, and MHVD were analyzed using the 80 percentile of total years tested. The ranges for EMTD, SHD, and MHVD were May 4 in Sariwon~May 24 in Sinpo, June 21 in Kanggye~August 11 in Haeju, and September 17 in Kanggye~October 16 in Haeju and Changjon, respectively. Time durations from EMTD to SHD and from SHD to MHVD were 67~97 days and 57~72 days, respectively, depending on the regions. This study would facilitate modeling efforts for rice yield simulation in future studies. Our results would also provide basic information for practical researches on the rice cropping system in North Korea.

• Journal of Animal Science and Technology
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• v.46 no.4
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• pp.509-516
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• 2004

This study is to investigate the amount of biased estimates for heritability and genetic correlation according to data structure on marbling scores in Korean cattle. Breeding population with 5 generations were simulated by way of selection for carcass weight, Longissimus muscle area and latent values of marbling scores and random mating. Latent variables of marbling scores were categorized into five by the thresholds of 0, I, 2, and 3 SD(DSI) or seven by the thresholds of -2, -1, 0,1I, 2, and 3 SD(DS2). Variance components and genetic pararneters(Heritabilities and Genetic correlations) were estimated by restricted maximum likelihood on multivariate linear mixed animal models and by Gibbs sampling algorithms on multivariate threshold mixed animal models in DS1 and DS2. Simulation was performed for 10 replicates and averages and empirical standard deviation were calculated. Using REML, heritabilitis of marbling score were under-estimated as 0.315 and 0.462 on DS1 and DS2, respectively, with comparison of the pararneter(0.500). Otherwise, using Gibbs sampling in the multivariate threshold animal models, these estimates did not significantly differ to the parameter. Residual correlations of marbling score to other traits were reduced with comparing the parameters when using REML algorithm with assuming linear and normal distribution. This would be due to loss of information and therefore, reduced variation on marbling score. As concluding, genetic variation of marbling would be well defined if liability concepts were adopted on marbling score and implemented threshold mixed model on genetic parameter estimation in Korean cattle.

• Nuclear Engineering and Technology
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• v.39 no.5
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• pp.603-616
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• 2007

Roy Huddle, having invented the coated particle in Harwell 1957, stated in the early 1970s that we know now everything about particles and coatings and should be going over to deal with other problems. This was on the occasion of the Dragon fuel performance information meeting London 1973: How wrong a genius be! It took until 1978 that really good particles were made in Germany, then during the Japanese HTTR production in the 1990s and finally the Chinese 2000-2001 campaign for HTR-10. Here, we present a review of history and present status. Today, good fuel is measured by different standards from the seventies: where $9*10^{-4}$ initial free heavy metal fraction was typical for early AVR carbide fuel and $3*10^{-4}$ initial free heavy metal fraction was acceptable for oxide fuel in THTR, we insist on values more than an order of magnitude below this value today. Half a percent of particle failure at the end-of-irradiation, another ancient standard, is not even acceptable today, even for the most severe accidents. While legislation and licensing has not changed, one of the reasons we insist on these improvements is the preference for passive systems rather than active controls of earlier times. After renewed HTGR interest, we are reporting about the start of new or reactivated coated particle work in several parts of the world, considering the aspects of designs/ traditional and new materials, manufacturing technologies/ quality control quality assurance, irradiation and accident performance, modeling and performance predictions, and fuel cycle aspects and spent fuel treatment. In very general terms, the coated particle should be strong, reliable, retentive, and affordable. These properties have to be quantified and will be eventually optimized for a specific application system. Results obtained so far indicate that the same particle can be used for steam cycle applications with $700-750^{\circ}C$ helium coolant gas exit, for gas turbine applications at $850-900^{\circ}C$ and for process heat/hydrogen generation applications with $950^{\circ}C$ outlet temperatures. There is a clear set of standards for modem high quality fuel in terms of low levels of heavy metal contamination, manufacture-induced particle defects during fuel body and fuel element making, irradiation/accident induced particle failures and limits on fission product release from intact particles. While gas-cooled reactor design is still open-ended with blocks for the prismatic and spherical fuel elements for the pebble-bed design, there is near worldwide agreement on high quality fuel: a $500{\mu}m$ diameter $UO_2$ kernel of 10% enrichment is surrounded by a $100{\mu}m$ thick sacrificial buffer layer to be followed by a dense inner pyrocarbon layer, a high quality silicon carbide layer of $35{\mu}m$ thickness and theoretical density and another outer pyrocarbon layer. Good performance has been demonstrated both under operational and under accident conditions, i.e. to 10% FIMA and maximum $1600^{\circ}C$ afterwards. And it is the wide-ranging demonstration experience that makes this particle superior. Recommendations are made for further work: 1. Generation of data for presently manufactured materials, e.g. SiC strength and strength distribution, PyC creep and shrinkage and many more material data sets. 2. Renewed start of irradiation and accident testing of modem coated particle fuel. 3. Analysis of existing and newly created data with a view to demonstrate satisfactory performance at burnups beyond 10% FIMA and complete fission product retention even in accidents that go beyond $1600^{\circ}C$ for a short period of time. This work should proceed at both national and international level.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.41 no.2
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• pp.23-34
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• 2004

Video camera can be a useful tool to capture images for use in colorimeter. However the RGB signals generated by different video camera are not equal for the same scene. The video camera for use in colorimeter is characterized based on the CIE standard colorimetric observer. One method of deriving a colorimetric characterization matrix between camera RGB output signals and CIE XYZ tristimulus values is least squares polynomial modeling. However it needs tedious experiments to obtain camera transfer matrix under various white balance point for the same camera. In this paper, a new method to obtain camera transfer matrix under different white balance by using 3${\times}$3 camera transfer matrix under a certain white balance point is proposed. According to the proposed method camera transfer matrix under any other white balance could be obtained by using colorimetric coordinates of phosphor derived from 3${\times}$3 linear transfer matrix under the certain white balance point. In experimental results, it is demonstrated that proposed method allow 3${\times}$3 linear transfer matrix under any other white balance having a reasonable degree of accuracy compared with the transfer matrix obtained by experiments.