• Title/Summary/Keyword: Management Criteria

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Right-Turn Vehicle Supplementary Signal Improvement at Intersections (교차로 우회전 차량 보조등 개선)

  • LEE, Nam Soo;KIM, Yu Chan;LIM, Joon Beom;KIM, Youngchan
    • Journal of Korean Society of Transportation
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    • v.33 no.5
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    • pp.441-448
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    • 2015
  • This study aims to suggest a reasonable signal operation method for right-turn traffic management. It was found that the right-turn vehicle supplementary signal is currently operated without clear regulations or criteria. It was also analyzed that right-turn supplementary signals are used without consistency, there is a risk of traffic accidents due to the discordance between supplementary signals and traffic signals of forward vehicles, there is a lack of basis for prohibition of a right turn when right-turn vehicle's supplementary signal is red and the flashing red signal is used in a different sense from the law. In order to see the effect of the installed right-turn vehicle supplementary signals on traffic signal violation, a field investigation was conducted. As the result, there was a high proportion of signal violation on the approach lane with right-turn supplementary signals and this means that right-turn supplementary signals hardly influenced the reduction in proportion of signal violation during a right turn. Additionally, a survey was carried out to see if there were differences in driver's interpretation of traffic signals depending on the installation of right-turn supplementary signals. As the result of the survey, there were no differences in interpretation of traffic signals depending on the installation of right-turn supplementary signals or the types of right-turn supplementary signals. A right turn when the signal was red did not lead to serious traffic accidents, so it is thought that there should be a careful consideration of a total ban on a right turn when the signal is red, in order to prevent driver's confusion due to the change of the signal system. Unless there is a disturbance to cars and pedestrians after a temporary stop when the signal is red, there is a need to specify that vehicles must stop temporarily in the Road Traffic Act to facilitate a right turn. What this study finally suggested is to use tri-colored arrow signals for right-turn car supplementary signals to convey a signal to a driver clearly.

An Overview of Korean Sharks Listed by the IUCN and CITES (IUCN과 CITES에 등재된 한국산 상어류의 현황)

  • Jeong, Choong-Hoon;Choi, Youn;Oh, Jeong-Kyu;Kim, Min-Seop;Jeong, Seung Jin
    • Korean Journal of Ichthyology
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    • v.28 no.2
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    • pp.125-133
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    • 2016
  • Sharks (Selachii) comprising about 510 valid species worldwide. Forty-three shark species belonging to 30 genera, 19 families and 8 orders have been found in Korean coastal waters, and all these are registered at the IUCN Red List as followings: endangered (EN) 1 species (2.3%) (vs. worldwide 15 spp., 3.2%), vulnerable (VU) 11 spp. (25.6%) (vs. 48 spp., 10.3%), near threatened (NT) 10 spp. (23.3%) (vs. 67 spp., 14.4%), least concern (LC) 9 spp. (20.9%) (vs. 115 spp., 24.7%), data deficient (DD) 12 spp. (27.9%) (vs. 209 spp., 44.9%), and critically endangered (CR) absent (vs. 11 spp., 2.4%). Twelve species among 43 sharks distributing in Korean waters are assessed as Threatened in the IUCN Red List categories and criteria as followings: Sphyrna lewini (EN, A2bd+4bd), Rhincodon typus (VU, A2bd+3d), Cetorhinus maximus (VU, A2ad+3d), Carcharodon carcharias (VU, A2cd+3cd), Isurus oxyrinchus (VU, A2abd+3bd+4abd), Alopias pelagicus (VU, A2d+4d), A. vulpinus (VU, A2bd+3bd+4bd), Carcharhinus plumbeus (VU, A2bd+4bd), S. zygaena (VU, A2bd+3bd+4bd), Squalus suckleyi (VU, A2bd+3bd+4bd), Squatina japonica (VU, A2d+4d), and S. nebulosa (VU, A2d+4d). Eighteen chondrichthyan species are registered in the list of the CITES Appendices, among them five sharks are distributing in Korean waters as Appendix II, i.e., R. typus, C. maximus, C. carcharias, S. lewini and S. zygaena. The scientific name of "Gobsangeo" has been changed from Squalus acanthias of the North Pacific to S. suckleyi, and "Mojorisangeo" from S. megalops of the Northwest Pacific to brevirostris.

The Prediction of DEA based Efficiency Rating for Venture Business Using Multi-class SVM (다분류 SVM을 이용한 DEA기반 벤처기업 효율성등급 예측모형)

  • Park, Ji-Young;Hong, Tae-Ho
    • Asia pacific journal of information systems
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    • v.19 no.2
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    • pp.139-155
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    • 2009
  • For the last few decades, many studies have tried to explore and unveil venture companies' success factors and unique features in order to identify the sources of such companies' competitive advantages over their rivals. Such venture companies have shown tendency to give high returns for investors generally making the best use of information technology. For this reason, many venture companies are keen on attracting avid investors' attention. Investors generally make their investment decisions by carefully examining the evaluation criteria of the alternatives. To them, credit rating information provided by international rating agencies, such as Standard and Poor's, Moody's and Fitch is crucial source as to such pivotal concerns as companies stability, growth, and risk status. But these types of information are generated only for the companies issuing corporate bonds, not venture companies. Therefore, this study proposes a method for evaluating venture businesses by presenting our recent empirical results using financial data of Korean venture companies listed on KOSDAQ in Korea exchange. In addition, this paper used multi-class SVM for the prediction of DEA-based efficiency rating for venture businesses, which was derived from our proposed method. Our approach sheds light on ways to locate efficient companies generating high level of profits. Above all, in determining effective ways to evaluate a venture firm's efficiency, it is important to understand the major contributing factors of such efficiency. Therefore, this paper is constructed on the basis of following two ideas to classify which companies are more efficient venture companies: i) making DEA based multi-class rating for sample companies and ii) developing multi-class SVM-based efficiency prediction model for classifying all companies. First, the Data Envelopment Analysis(DEA) is a non-parametric multiple input-output efficiency technique that measures the relative efficiency of decision making units(DMUs) using a linear programming based model. It is non-parametric because it requires no assumption on the shape or parameters of the underlying production function. DEA has been already widely applied for evaluating the relative efficiency of DMUs. Recently, a number of DEA based studies have evaluated the efficiency of various types of companies, such as internet companies and venture companies. It has been also applied to corporate credit ratings. In this study we utilized DEA for sorting venture companies by efficiency based ratings. The Support Vector Machine(SVM), on the other hand, is a popular technique for solving data classification problems. In this paper, we employed SVM to classify the efficiency ratings in IT venture companies according to the results of DEA. The SVM method was first developed by Vapnik (1995). As one of many machine learning techniques, SVM is based on a statistical theory. Thus far, the method has shown good performances especially in generalizing capacity in classification tasks, resulting in numerous applications in many areas of business, SVM is basically the algorithm that finds the maximum margin hyperplane, which is the maximum separation between classes. According to this method, support vectors are the closest to the maximum margin hyperplane. If it is impossible to classify, we can use the kernel function. In the case of nonlinear class boundaries, we can transform the inputs into a high-dimensional feature space, This is the original input space and is mapped into a high-dimensional dot-product space. Many studies applied SVM to the prediction of bankruptcy, the forecast a financial time series, and the problem of estimating credit rating, In this study we employed SVM for developing data mining-based efficiency prediction model. We used the Gaussian radial function as a kernel function of SVM. In multi-class SVM, we adopted one-against-one approach between binary classification method and two all-together methods, proposed by Weston and Watkins(1999) and Crammer and Singer(2000), respectively. In this research, we used corporate information of 154 companies listed on KOSDAQ market in Korea exchange. We obtained companies' financial information of 2005 from the KIS(Korea Information Service, Inc.). Using this data, we made multi-class rating with DEA efficiency and built multi-class prediction model based data mining. Among three manners of multi-classification, the hit ratio of the Weston and Watkins method is the best in the test data set. In multi classification problems as efficiency ratings of venture business, it is very useful for investors to know the class with errors, one class difference, when it is difficult to find out the accurate class in the actual market. So we presented accuracy results within 1-class errors, and the Weston and Watkins method showed 85.7% accuracy in our test samples. We conclude that the DEA based multi-class approach in venture business generates more information than the binary classification problem, notwithstanding its efficiency level. We believe this model can help investors in decision making as it provides a reliably tool to evaluate venture companies in the financial domain. For the future research, we perceive the need to enhance such areas as the variable selection process, the parameter selection of kernel function, the generalization, and the sample size of multi-class.

The Effect of Social Network on Information Sharing in Franchise System (프랜차이즈시스템의 사회연결망 특성이 정보공유에 미치는 영향)

  • Yun, Han-Sung;Bae, Sang-Wook;Noh, Jung-Koo
    • Journal of Distribution Research
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    • v.16 no.2
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    • pp.95-118
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    • 2011
  • The purpose of this study is as follows. First, we investigate empirically the effects of social network properties such as social network density and centrality of a franchisee on its information sharing with various subjects such as the franchisor and other franchisees in the franchise system. Second, we examine exploratively if tie strength between a franchisee and its franchisor plays a moderating role on the relationship between social network properties and information sharing. The study model was established as shown in

    . We gathered 200 data from franchisees in Busan through a questionnaire survey and used 189 data for our purpose. To improve the quality of data, we selected respondents from the franchisees' owners or managers that had contacted often with their franchisor and other franchisees in the franchise system. Our data analysis began with reliability analysis, exploratory and confirmatory factor analysis, on the multi-item measures of social network density, social network centrality, tie strength, information sharing and control variables such as shared goals and ownership to assess the reliability and validity of those measures. The results were shown that the presented values satisfied the general criteria for reliability and validity. We tested our hypotheses using a hierarchical multiple regression analysis in four steps. Model 1 regressed the dependent variable(information sharing) only on control variables(shared goals, ownership). Model 2 added main effect variables(social network density, social network centrality) in Model 1. Model 3 added a moderating variable(tie strength) in Model 2. Finally, Model 4 added interaction terms between the main variables and the moderating variable in Model 3. We used a mean-centering method for the main variables and the moderating variable to minimize the multicollinearity problem due to the interaction terms in Model 4. Two important empirical findings emerge from this study. In other words, the effects of social network properties and tie strength on a franchisee's information sharing depend on subject types such as the franchisor and other franchisees in franchise system. First, social network centrality, tie strength, the interaction between social network density and tie strength and the interaction between social network centrality and tie strength all affect significantly a franchisee's information sharing with its franchisor. By the way, the interaction between social network centrality and tie strength has a negative effect on its information sharing while the interaction of social network density and tie strength has a positive effect on its information sharing. Second, both social network centrality affects significantly and directly a franchisee's information sharing with other franchisees in the franchise system. However, there does not exist the moderating role of tie strength in the second case. Finally, we suggest the implications of our findings and some avenues for future research.

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Seasonal Distribution of Bacterial Populations and Escherichia coli O157 at Hanwoo Cattle Feedlots in Gyeongsangbuk-do (경상북도 한우축사에서의 계절별 세균 및 Escherichia coli O157 분포 변화)

  • Khang, Yong-Ho;Kang, Moon-Sook
    • Korean Journal of Microbiology
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    • v.45 no.2
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    • pp.222-227
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    • 2009
  • The seasonal variation of bacterial populations in the Korean cattle (Hanwoo) feedlots dispersed in the 20 cities of Gyeongsangbuk-do, Korea, was monitored for two years (2006 and 2007) to provide quantitative criteria for good agricultural management. Outside the feedlots, the average falling bacterial populations of the air were $3{\pm}1$ CFU/$cm^2\cdot15$ min (n=63) in a year. Inside the feedlots, the average falling bacterial populations of the air were $8{\pm}1$ CFU/$cm^2\cdot15$ min (n=63) in the spring, $16{\pm}2$ CFU/$cm^2\cdot15$ min (n=69) in the summer, $7{\pm}2$ CFU/$cm^2\cdot15$ min (n=69) in the autumn, and $6{\pm}1$ CFU/$cm^2\cdot15$ min (n=70) in the winter. Without using the summer data, the average falling bacterial population of the air was $7{\pm}1$ CFU/$cm^2\cdot15$ min, which was not statistically significant (P=0.37). The average bacterial populations in the cattle drinking water of the cattle feedlots were $4,710{\pm}780$ CFU/ml (n=65) in the spring, $10,430{\pm}1170$ CFU/ml (n=65) in the summer, $4,820{\pm}700$ CFU/ml (n=64) in the autumn, and $2,510{\pm}530$ CFU/ml (n=64) in the winter. Without using the summer data, the average bacterial population of the drinking water was $4,000{\pm}400$ CFU/ml, which was statistically significant (P=0.027). The average frequency of Escherichia coli O157 inside the feedlots was 5% (n=65) in the spring, 72% (n=65) in the summer, 67% (n=66) in the autumn, and 29% (n=66) in the winter on the basis of soil samples of the year 2007. The results indicate that most of the Escherichia coli O157 strains distributed in the summer and autumn was disappeared in the spring through the cold weather of the winter.

A Study on the Lime Stabilization of Livestock Waste (축산폐기물의 안정화 처리에 대한 연구)

  • Kim, Hyun-Chul;Choi, Yong-Su
    • Analytical Science and Technology
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    • v.8 no.1
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    • pp.91-99
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    • 1995
  • One of alternative conventional technologies used for treatment of livestock wastes is composting process, and recently some mechanical composting processes are being practiced. It is, however, recognized the composting process also has its own limitations such as longer time requirement, and difficulties to estimate the degree of decomposition, etc. The incomplete compost contains potentially harmful materials to crops and public health due to instabilized organic contents and pathogenic organisms. The purpose of this investigation is to develop an innovative system whereby anxious livestock wastes are thoroughly stabilized and disinfected. Thus the overall management scheme should meet the following requirements. 1. A system should be in a cost-effective and environmentally sound manner. 2. Sludges must be chemically stabilized and bacteriologically safe. 3. Odor-free by product should be applied to crop land. 4. Sludges are sources of fertilizer nutrients and/or soil amendments to enhance crop production. 5. And they can be used as potential pH adjusting agent of the acidified soils. Overall effectiveness of the developed system is experimentally tested to satisfy the preset criteria and requirements. Major experiments are divided into four categories: they are 1. chemical stability test, 2. optimal condition test of stabilization process, 3. bacteriological examination and disinfection tests, and 4. deodorization tests The stabilization process is consisted of the stabilizing reaction process and the drying process. Stabilized wastes is dried by both sun dryer and rotary dryer. It is shown that an additive dosage of about g/kg solid in wastes with a minimum of 5-minutes reaction would be necessary for effective stabilization reaction. The stabilization process is consisted of the stabilizing reaction process and drying process. Stabilized wastes are dried by both sun dryer and rotary dryer. It is shown that an additive dosage of about 300g/kg solid in wastes with a minimum of 5-minutes reaction would be necessary for effective stabilization reaction. In the stabilization reaction process, the pH of wastes is lowered from initial values of 12.3 to 8.6. High pH prevents odor production and kills pathogenic organisms. Organic matter contents in the stabilized wastes are about 50% and the sum of contents of fertilizer elements such as total nitrogen, $P_2O_5$ and $K_2O$ are about 5.3%. The livestock wastes that are stabilized chemically and hygienically can be used as a good soil conditioner and/or organic fertilizer.

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Modified QuEChERS Multi-Residue Analysis Method for 61 pesticides in Fruits using with HPLC and GC-ECD/NPD (HPLC 및 GC-ECD/NPD를 이용한 과일 중 61종 농약의 QuEChERS 전처리 다성분 분석법 개발)

  • Lee, Ju-Young;Hong, Su-Myeong;Kim, Taek-Kyum;Min, Zaw Win;Kim, Yang-Hyeon;Song, Kyung-Ae;Kwon, Hye-Yong;Lee, Hee-Dong;Im, Geon-Jae;Kim, Doo-Ho;Kim, Jang-Eok
    • The Korean Journal of Pesticide Science
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    • v.16 no.3
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    • pp.242-256
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    • 2012
  • QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) method has been a lot of research for pesticide analysis, because it is very simple and fast. However, this method requires high sensitivity instrument such as LC-MS/MS because of the use of small sample volume and many impurities compared to the conventional method. So, QuEChERS method needs to be modified for using with HPLC and GC-ECD/NPD. The aim of this work was to study the application of the QuEChERS method as well as its modification for the extraction and preconcentration of 5 groups of 61 pesticides from 4 fruits prior to their determination by HPLC-PDA, GC-ECD/NPD, and LC-MS/MS. The method was validated using spiking levels at 0.1 mg/kg (or 0.01 mg/kg) in apple, grapes, pear and persimmon. The average recovery by QuEChERS AOAC Official 2007. 01 version using the LC-MS/MS varied from 71.1127.4% for 61 pesticides. The average recovery rates using modified QuEChERS varied from 70.9~126% for 61 pesticides by HPLC-PDA and GC-ECD/NPD. The results satisfied the criteria of multiple pesticide residue analysis, setting 70~130% for recovery rates and below 30% for CV.

Risk Factors for the Progression of Pediatric Chronic Kidney Disease-A Single Center Study (소아 만성 신질환 진행의 위험인자 분석-단일기관 연구)

  • Han, Kyoung-Hee;Lee, Sung-Ha;Lee, Hyun-Kyung;Choi, Hyun-Jin;Lee, Bum-Hee;Cho, Hee-Yeon;Cheong, Hae-Il;Choi, Yong;Ha, Il-Soo
    • Childhood Kidney Diseases
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    • v.11 no.2
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    • pp.239-246
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    • 2007
  • Purpose : The progressive deterioration of renal function in children can impose a serious and lifelong impact on their lives. The ultimate goal in the management of children with chronic kidney disease(CKD) is to prolong survival, to prevent complications, and to promote growth and neurodevelopment. The aim of this study is to investigate the risk factors for the decline of renal function in pediatric CKD patients. Methods : Data from patients who met the criteria for the Kidney Disease Outcomes Quality Initiative(K/DOQI) CKD stage 2 to 4 between August 1999 and March 2007 were retrospectively analyzed. The estimated glomerular filtration rate(eGFR) was calculated by the Schwartz formula, using serum creatinine levels and height. We calculated the annual eGFR change from the difference between the baseline eGFR and the last eGFR divided by the duration(years) of the follow-up period. We analyzed the association between the annual eGFR change and factors such as age, gender, K/DOQI stage, underlying renal disease, serum calcium, and inorganic phosphorous during the follow-up period. Results : Sixty one children(44 boys & 17 girls) were enrolled. The age at entry was $7.1{\pm}4.7$ years. The annual eGFR change was $-1.2{\pm}11.9 mL/min/1.73m^2/year$. Our study showed that older age(P=0.005). hypocalcemia(P=0.012), and hypenhosphatemia(P=0.002) were significantly related to more rapid decline in renal function. Conclusion : In pediatric CKD, older age, hypocalcemia and hyperphosphatemia are related to more rapid deterioration of renal function.

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Optimal Application Rate of Mixed Expeller Cake and Rice Straw and Impacts on Physical Properties of Soil in Organic Cultivation of Tomato (토마토 유기재배에서 혼합유박과 볏짚의 적정시용량 및 토양 물리성에 미치는 영향)

  • Lim, Tae-Jun;Park, Jin-Myeon;Lee, Seong-Eun;Jung, Hyun-Cheol;Jeon, Sang-Ho;Hong, Soon-Dal
    • Korean Journal of Environmental Agriculture
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    • v.30 no.2
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    • pp.105-110
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    • 2011
  • BACKGROUND: In this study, 5 different treatments such as non-treatment, mixed expeller cake 1.0 N (standard nitrogen fertilizer), rice straw, rice straw+mixed expeller cake 0.5 N, rice straw+mixed expeller cake 1.0 N were performed over 4 cropping seasons over 2 years in order to identify the optimal application rate of mixture of rice straw and mixed expeller cake, organic source in organic cultivation of tomatoes. METHODS AND RESULTS: There was no difference in all treatments in case of 200 mg/kg in the nitrate nitrogen content in soil prior to the first cropping season test under the criteria for nitrogen nutrient based on yield of crops, cultivation without fertilizers seems possible. But in the second cropping season, no treatment and rice straw showed the reduction of yield and in the third cropping season, rice-straw+mixed expeller cake 0.5 N treatment showed the significant difference. The content of nitrate nitrogen in soil prior to cropping seasons was evaluated in 160 mg/kg and standard fertilization such as mixed expeller cake, source of nitrogen, are needed due to the deficiency of nitrogen. In terms of application of organic resources, rice straw showed the effects of improvements on physical properties of soil such as bulk density, cation exchange capacity and humus contents, but the mixed expeller cake did not show any significant differences in improvements on physical properties of soil. CONCLUSION(s): Fertilizer management in organic cultivation of tomatoes is thought to produce the reliable quantity of crops as well as keep the high quality of soils by using the optimal application rate of mixed expeller cake according to the contents of nitrate nitrogen in soil and rice straw which improves the physical properties of soil.

Evaluation of Sanitary Safety for Shellfish in Hansan·Geojeman, Korea (경남 한산·거제만해역에서 생산된 패류의 위생학적 안전성 평가)

  • Ha, Kwang-Soo;Lee, Ka-Jeong;Jeong, Yeon-Jung;Mok, Jong-Soo;Kim, Poong-Ho;Kim, Yeon-Kye;Lee, Hee-Jung;Kim, Dong-Wook;Son, Kwang-Tae
    • Journal of Food Hygiene and Safety
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    • v.33 no.5
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    • pp.404-411
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    • 2018
  • To evaluate bacteriological and toxicological safety hygienic indicator bacterium and paralytic and diarrhetic shellfish toxins in the shellfish produced in Hansan Geojeman 2013-2017 were investigated. Fecal coliforms were < 18~330 MPN/100 g in 404 oyster samples. But all samples tested, did not exceed 230 E. coli MPN/100 g. Geometric mean of E. coli for oyster samples collected during major shellfish production period was 24.3 MPN/100 g, considerde stable results. Bacteriological quality of oysters collected from Hansan Geojeman meets the standard value based on shellfish hygiene of the Food Sanitation Act of Korea and also meets Grade A, according to classification of shellfish harvesting areas of the European Union. For toxicological evaluation of Hansan Geojeman, 532 oyster samples and 268 mussel samples as an indicator, were analyzed. Paralytic shellfish toxins were detected in the range of 0.42~2.29 mg/kg in eight mussel samples, and exceeded criteria in three samples from early to late April 2013. Diarrhetic shellfish toxin was detected in three of 120 samples, but it was revealed to be under regulation value (0.16 mg Okadaic Acid equ./kg). As a result of toxicological evaluation, paralytic and diarrhetic shellfish toxins were not detected in oyster samples, but it was found that mussel as an indicator species, exceeded the threshold value of paralytic shellfish toxin. Accordingly, sanitary surveys were continuously requested for food safety management of shellfish.