• Title/Summary/Keyword: Efficient operation

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Characterization of Cement Solidification for Enhancement of Cesium Leaching Resistance (세슘 침출 저항성 증진 시멘트 고화체의 제조 및 특성 평가)

  • Kim, Gi Yong;Jang, Won-Hyuk;Jang, Sung-Chan;Im, Junhyuck;Hong, Dae Seok;Seo, Chel Gyo;Shon, Jong Sik
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.16 no.2
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    • pp.183-193
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    • 2018
  • Currently, the Korea Atomic Energy Research Institute (KAERI) is planning to build the Ki-Jang Research Reactor (KJRR) in Ki-Jang, Busan. It is important to safely dispose of low-level radioactive waste from the operation of the reactor. The most efficient way to treat radioactive waste is cement solidification. For a radioactive waste disposal facility, cement solidification is performed based on specific waste acceptance criteria such as compressive strength, free-standing water, immersion and leaching tests. Above all, the leaching test is important to final disposal. The leakage of radioactive waste such as $^{137}Cs$ causes not only regional problems but also serious global ones. The cement solidification method is simple, and cheaper than other solidification methods, but has a lower leaching resistance. Thus, this study was focused on the development of cement solidification for an enhancement of cesium leaching resistance. We used Zeolite and Loess to improve the cesium leaching resistance of KJRR cement solidification containing simulated KJRR liquid waste. Based on an SEM-EDS spectrum analysis, we confirmed that Zeolite and Loess successfully isolated KJRR cement solidification. A leaching test was carried out according to the ANS 16.1 test method. The ANS 16.1 test is performed to analyze cesium ion concentration in leachate of KJRR cement for 90 days. Thus, a leaching test was carried out using simulated KJRR liquid waste containing $3000mg{\cdot}L^{-1}$ of cesium for 90 days. KJRR cement solidification with Zeolite and Loess led to cesium leaching resistance values that were 27.90% and 21.08% higher than the control values. In addition, in several tests such as free-standing water, compressive strength, immersion, and leaching tests, all KJRR cement solidification met the waste acceptance or satisfied the waste acceptance criteria for final disposal.

Effects of Cohort Size on Male Experience-Earnings Profiles in Korea (코호트 사이즈가 경력-임금 곡선에 미치는 영향)

  • 신영수
    • Korea journal of population studies
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    • v.10 no.1
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    • pp.50-69
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    • 1987
  • There are about 400, 000 Korean ethnics living in Central Asia. Most of Koreans in Central Asia are leading a stable middle class life mostly engaged in farm work. With increase of educational attainment of their children, a number of Koreans are launching into political and academic circles as well as in the cultural world or the press. In recent years, however, the countries in this area(Uzbekistan and Kazakstan) for this study advocate an ethnic united policy to stabilize the politics and society and to carry out efficient transformation from the former socialistic economy to a market oriented economy. In addition, they are trying to recover the culture and the language of each nation which has been forgotten in the assimilation of Russia policy. Koreans have difficulty in adaption to this kind of change. In fact, a number of Koreans lost traditional culture and could not speak their mother language - Korean. Although they more or less maintain national consciousness, they recognize Uzbekistan or Kazakstan as their nation politically. They associated with North Korea unilaterally before the launching of the Perestroika policy. But after the Seoul Olympics held in 1998, there was movement to know and understand South Korea. There has been increased in the investment by Korean companies in Central Asia. Now, what is an alternative idea for Korean community consciousness\ulcorner It can be summarized as follows: 1) The increase of aid to Korean education institute : Considering the last few decades of Russia's strong racial assimilation policy, which leads most Koreans to lost their language and national culture, the priority should go to Koreans education. 2) Local Korean press support : Though Korean newspaper are published and Korean broadcasting is on the air currently in Uzbekistan and Kazakstan, they are suffering from qualified staff and poor financial status. Therefore, positive support should be established for these Korean mass communication media outlets to recover their own function and expand their dissemination powers quickly. 3) Research on the actual condition for Korean Community : It is essential to directly examine the local Korean community's regional distribution, population structure, Korean group's formation and operation, social and cultural understanding, racial consciousness, hope for their mother land and much more. 4) Increase of mother land and education opportunity : To stir up national culture and national consciousness within the Korean community, it is necessary to expand continuous opportunities for mother land visits and education training for local Koreans, especially for second and third generations.

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A Study on the Integrated Utilization of Nationally-Supported Research Vessels Using Cost-Benefit Analysis (비용-편익 분석을 통한 국가 해양 연구·조사선의 최적 통합활용 방안 연구)

  • Park, Cheong Kee;Park, Se Hun;Park, Seong Wook;Lee, Gun Chang
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.23 no.6
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    • pp.719-730
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    • 2017
  • Recently, oceanic research has been carried out investigating global scientific interests and the territorial management of national marine jurisdictional waters, including exclusive economic zones (EEZ) and the open seas. To meet the needs of ocean researchers pursuing these - objectives, acquiring advanced research infrastructure, including research vessels, large facilities, and equipment, is a top priority in ocean science. However, ocean science is a similar to space science, and securing resources and state-of-the-art technology can be expensive. Faced with these challenges, our study focused on establishing a strategy for the efficient operation and management of research vessels, attempting to establish benchmarks from foreign examples that can be adapted to suit the target context. The results of this study provide ways to identify operating systems that could increase the efficiency of joint-use research vessels. The different systems examined in this study included a joint-use committee-based management system (JCMS, Type 1), private enterprise entrusted operating system (PEOS, Type 2), institutional investment operating system (IIOS, Type 3), and commissioned executive operating system (CEOS, Type 4). The efficiencies of JCMS, PEOS, IIOS and CEOS were 9.17, 5.82, 11.2 and -1.72 %, respectively. Given the total costs involved, the most affordable operating system was IIOS. JCMS was the most cost-effective system based on a quantitative cost-benefit analysis, but IIOS also had an acceptable cost-benefit balance. An operational committee would be required and regulations and guidelines shoulde be established to employ, JCMS, while a strategy to yield independent revenue would be needed to utilize an IIOS system.

Study on the Selecting of Suitable Sites for Integrated Riparian Eco-belts Connecting Dam Floodplains and Riparian Zone - Case Study of Daecheong Reservoir in Geum-river Basin - (댐 홍수터와 수변구역을 연계한 통합형 수변생태벨트 적지 선정방안 연구 - 금강 수계 대청호 사례 연구 -)

  • Bahn, Gwonsoo;Cho, Myeonghyeon;Kang, Jeonkyeong;Kim, Leehyung
    • Journal of Wetlands Research
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    • v.23 no.4
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    • pp.327-341
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    • 2021
  • The riparian eco-belt is an efficient technique that can reduce non-point pollution sources in the basin and improve ecological connectivity and health. In Korea, a legal system for the construction and management of riparian eco-belts is in operation. However, it is currently excluded that rivers and floodplains in dam reservoir that are advantageous for buffer functions such as control of non-point pollutants and ecological habitats. Accordingly, this study presented and analyzed a plan to select a site for an integrated riparian ecol-belt that comprehensively evaluates the water quality and ecosystem characteristics of each dam floodplain and riparian zone for the Daecheong Dam basin in Geum River watershed. First, the Daecheong Dam basin was divided into 138 sub-basin with GIS, and the riparian zone adjacent to the dam floodplain was analyzed. Sixteen evaluation factors related to the ecosystem and water quality impact that affect the selection of integrated riparian eco-belt were decided, and weights for the importance of each factor were set through AHP analysis. The priority of site suitability was derived by conducting an integrated evaluation by applying weights to sub-basin by floodplains and riparian zone factors. In order to determine whether the sites derived through GIS site analysis are sutiable for actual implementation, five sites were inspected according to three factors: land use, pollution sources, and ecological connectivity. As a result, it was confirmed that all sites were appropriate to apply integrated riparian ecol-belt. It is judged that the riparian eco-belt site analysis technique proposed through this study can be applied as a useful tool when establishing an integrated riparian zone management policy in the future. However, it might be necessary to experiment various evaluation factors and weights for each item according to the characteristics and issues of each dam. Additional research need to be conducted on elaborated conservation and restoration strategies considering the Green-Blue Network aspect, evaluation of ecosystem services, and interconnection between related laws and policy and its improvements.

Particulate Matter and CO2 Improvement Effects by Vegetation-based Bio-filters and the Indoor Comfort Index Analysis (식생기반 바이오필터의 미세먼지, 이산화탄소 개선효과와 실내쾌적지수 분석)

  • Kim, Tae-Han;Choi, Boo-Hun;Choi, Na-Hyun;Jang, Eun-Suk
    • Korean Journal of Environmental Agriculture
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    • v.37 no.4
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    • pp.268-276
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    • 2018
  • BACKGROUND: In the month of January 2018, fine dust alerts and warnings were issued 36 times for $PM_{10}$ and 81 times for PM2.5. Air quality is becoming a serious issue nation-wide. Although interest in air-purifying plants is growing due to the controversy over the risk of chemical substances of regular air-purifying solutions, industrial spread of the plants has been limited due to their efficiency in air-conditioning perspective. METHODS AND RESULTS: This study aims to propose a vegetation-based bio-filter system that can assure total indoor air volume for the efficient application of air-purifying plants. In order to evaluate the quantitative performance of the system, time-series analysis was conducted on air-conditioning performance, indoor air quality, and comfort index improvement effects in a lecture room-style laboratory with 16 persons present in the room. The system provided 4.24 ACH ventilation rate and reduced indoor temperature by $1.6^{\circ}C$ and black bulb temperature by $1.0^{\circ}C$. Relative humidity increased by 24.4% and deteriorated comfort index. However, this seemed to be offset by turbulent flow created from the operation of air blowers. While $PM_{10}$ was reduced by 39.5% to $22.11{\mu}g/m^3$, $CO_2$ increased up to 1,329ppm. It is interpreted that released $CO_2$ could not be processed because light compensation point was not reached. As for the indoor comfort index, PMV was reduced by 83.6 % and PPD was reduced by 47.0% on average, indicating that indoor space in a comfort range could be created by operating vegetation-based bio-filters. CONCLUSION: The study confirmed that the vegetation-based bio-filter system is effective in lowering indoor temperature and $PM_{10}$ and has positive effects on creating comfortable indoor space in terms of PMV and PPD.

A Study on Differentiation and Improvement in Arbitration Systems in Construction Disputes (건설분쟁 중재제도의 차별화 및 개선방안에 관한 연구)

  • Lee, Sun-Jae
    • Journal of Arbitration Studies
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    • v.29 no.2
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    • pp.239-282
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    • 2019
  • The importance of ADR(Alternative Dispute Resolution), which has the advantage of expertise, speed and neutrality due to the increase of arbitration cases due to domestic and foreign construction disputes, has emerged. Therefore, in order for the nation's arbitration system and the arbitration Organization to jump into the ranks of advanced international mediators, it is necessary to research the characteristics and advantages of these arbitration Organization through a study of prior domestic and foreign research and operation of international arbitration Organization. As a problem, First, education for the efficient promotion of arbitrators (compulsory education, maintenance education, specialized education, seminars, etc.). second, The effectiveness of arbitration in resolving construction disputes (hearing methods, composition of the tribunal, and speed). third, The issue of flexibility and diversity of arbitration solutions (the real problem of methodologies such as mediation and arbitration) needs to be drawn on the Arbitration laws and practical problems, such as laws, rules and guidelines. Therefore, Identify the problems presented in the preceding literature and diagnosis of the defects and problems of the KCAB by drawing features and benefits from the arbitration system operated by the international arbitration Institution. As an improvement, the results of an empirical analysis are derived for "arbitrator" simultaneously through a recognition survey. As a method of improvement, First, as an optimal combination of arbitration hearing and judgment in the settlement of construction disputes,(to improve speed). (1) A plan to improve the composition of the audit department according to the complexity, specificity, and magnification of the arbitration cases - (1)Methods to cope with the increased role of the non-lawyer(Specialist, technical expert). (2)Securing technical mediators for each specialized expert according to the large and special corporation arbitration cases. (2) Improving the method of writing by area of the arbitration guidelines, second, Introduction of the intensive hearing system for psychological efficiency and the institutional improvement plan (1) Problems of optimizing the arbitration decision hearing procedure and resolution of arbitration, and (2) Problems of the management of technical arbitrators of arbitration tribunals. (1)A plan to expand hearing work of technical arbitrator(Review on the introduction of the Assistant System as a member of the arbitration tribunals). (2)Improved use of alternative appraisers by tribunals(cost analysis and utilization of the specialized institution for calculating construction costs), Direct management of technical arbitrators : A Study on the Improvement of the Assessment Reliability of the Appraisal and the Appraisal Period. third, Improvement of expert committee system and new method, (1) Creating a non-executive technical committee : Special technology affairs, etc.(Major, supports pre-qualification of special events and coordinating work between parties). (2) Expanding the standing committee.(Added expert technicians : important, special, large affairs / pre-consultations, pre-coordination and mediation-arbitration). This has been shown to be an improvement. In addition, institutional differentiation to enhance the flexibility and diversity of arbitration. In addition, as an institutional differentiation to enhance the flexibility and diversity of arbitration, First, The options for "Med-Arb", "Arb-Med" and "Arb-Med-Arb" are selected. second, By revising the Agreement Act [Article 28, 2 (Agreement on Dispute Resolution)], which is to be amended by the National Parties, the revision of the arbitration settlement clause under the Act, to expand the method to resolve arbitration. third, 2017.6.28. Measures to strengthen the status role and activities of expert technical arbitrators under enforcement, such as the Act on Promotion of Interestments Industry and the Information of Enforcement Decree. Fourth, a measure to increase the role of expert technical Arbitrators by enacting laws on the promotion of the arbitration industry is needed. Especially, the establishment of the Act on Promotion of Intermediation Industry should be established as an international arbitration agency for the arbitration system. Therefore, it proposes a study of improvement and differentiation measures in the details and a policy, legal and institutional improvement and legislation.

Application of Automated Microscopy Equipment for Rock Analog Material Experiments: Static Grain Growth and Simple Shear Deformation Experiments Using Norcamphor (유사물질 실험을 위한 자동화 현미경 실험 기기의 적용과 노캠퍼를 이용한 입자 성장 및 단순 전단 변형 실험의 예)

  • Ha, Changsu;Kim, Sungshil
    • Economic and Environmental Geology
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    • v.54 no.2
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    • pp.233-245
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    • 2021
  • Many studies on the microstructures in rocks have been conducted using experimental methods with various equipment as well as natural rock studies to see the development of microstructures and understand their mechanisms. Grain boundary migration of mineral aggregates in rocks could cause grain growth or grain size changes during metamorphism or deformation as one of the main recrystallization mechanisms. This study suggests improved ways regarding the analog material experiments with reformed equipment to see sequential observations of these grain boundary migration. It can be more efficient than the existing techniques and carry out an appropriate microstructure analysis. This reformed equipment was implemented to enable optical manipulation by mounting polarizing plates capable of rotating operation on a stereoscopic microscope and a deformation rig capable of experimenting with analog materials. The equipment can automatically control the temperature and strain rate of the deformation rig by microcontrollers and programming and can take digital photomicrographs with constant time intervals during the experiment to observe any microstructure changes. The composite images synthesized using images by rotated polarizing plates enable us to see more accurate grain boundaries. As a rock analog material, norcamphor(C7H10O) was used, which has similar birefringence to quartz. Static grain growth and simple shear deformation experiments were performed using the norcamphor to verify the effectiveness of the equipment. The static grain growth experiments showed the characteristics of typical grain growth behavior. The number of grains decreases and the average grain size increases over time. These case experiments also showed a clear difference between the growth curves with three temperature conditions. The result of the simple shear deformation experiment under the medium temperature-low strain rate showed no significant change in the average grain size but presented the increased elongation of grain shapes in the direction of about 53° regarding the direction perpendicular to the shearing direction as the shear strain increases over time. These microstructures are interpreted as both the plastic deformation and the internal recovery process in grains are balanced by the deformation under the given experimental conditions. These experiments using the reformed equipment represent the ability to sequentially observe changing the microstructure during experiments as desired in the tests with the analog material during the entire process.

A Study on Evaluating the Possibility of Monitoring Ships of CAS500-1 Images Based on YOLO Algorithm: A Case Study of a Busan New Port and an Oakland Port in California (YOLO 알고리즘 기반 국토위성영상의 선박 모니터링 가능성 평가 연구: 부산 신항과 캘리포니아 오클랜드항을 대상으로)

  • Park, Sangchul;Park, Yeongbin;Jang, Soyeong;Kim, Tae-Ho
    • Korean Journal of Remote Sensing
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    • v.38 no.6_1
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    • pp.1463-1478
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    • 2022
  • Maritime transport accounts for 99.7% of the exports and imports of the Republic of Korea; therefore, developing a vessel monitoring system for efficient operation is of significant interest. Several studies have focused on tracking and monitoring vessel movements based on automatic identification system (AIS) data; however, ships without AIS have limited monitoring and tracking ability. High-resolution optical satellite images can provide the missing layer of information in AIS-based monitoring systems because they can identify non-AIS vessels and small ships over a wide range. Therefore, it is necessary to investigate vessel monitoring and small vessel classification systems using high-resolution optical satellite images. This study examined the possibility of developing ship monitoring systems using Compact Advanced Satellite 500-1 (CAS500-1) satellite images by first training a deep learning model using satellite image data and then performing detection in other images. To determine the effectiveness of the proposed method, the learning data was acquired from ships in the Yellow Sea and its major ports, and the detection model was established using the You Only Look Once (YOLO) algorithm. The ship detection performance was evaluated for a domestic and an international port. The results obtained using the detection model in ships in the anchorage and berth areas were compared with the ship classification information obtained using AIS, and an accuracy of 85.5% and 70% was achieved using domestic and international classification models, respectively. The results indicate that high-resolution satellite images can be used in mooring ships for vessel monitoring. The developed approach can potentially be used in vessel tracking and monitoring systems at major ports around the world if the accuracy of the detection model is improved through continuous learning data construction.

Priority Analysis of Cause Factors of Safety Valve Failure Mode Using Analytical Hierarchy Process (AHP를 활용한 안전밸브(PSV) 고장모드의 Cause Factors 우선순위 분석)

  • Kim, Myung Chul;Lee, Mi Jeong;Lee, Dong Geon;Baek, Jong-Bae
    • Korean Chemical Engineering Research
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    • v.60 no.3
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    • pp.347-355
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    • 2022
  • The safety valve (PSV) is a safety device that automatically releases a spring when the pressure generated by various causes reaches the set pressure, and is restored to a normal state when the pressure falls below a certain level. Periodic inspection and monitoring of safety valves are essential so that they can operate normally in abnormal conditions such as pressure rise. However, as the current safety inspection is performed only at a set period, it is difficult to ensure the safety of normal operation. Therefore, evaluation items were developed by finding failure modes and causative factors of safety valves required for safety management. In addition, it is intended to provide decision-making information for securing safety by deriving the priority of items. To this end, a Delphi survey was conducted three times to derive evaluation factors that were judged to be important in relation to the Failure Mode Cause Factor (FMCFs) of the safety valve (PSV) targeting 15 experts. As a result, 6 failure modes of the safety valve and 22 evaluation factors of its sub-factors were selected. In order to analyze the priorities of the evaluation factors selected in this way, the hierarchical structure was schematized, and the hierarchical decision-making method (AHP) was applied to the priority calculation. As a result of the analysis, the failure mode priorities of FMCFs were 'Leakage' (0.226), 'Fail to open' (0.201), 'Fail to relieve req'd capacity' (0.152), 'Open above set pressure' (0.149), 'Spuriously' 'open' (0.146) and 'Stuck open' (0.127) were confirmed in the order. The lower priority of FMCFs is 'PSV component rupture' (0.109), 'Fail to PSV size calculation' (0.068), 'PSV Spring aging' (0.065), 'Erratic opening' (0.059), 'Damage caused by improper installation and handling' (0.058), 'Fail to spring' (0.053), etc. were checked in the order. It is expected that through efficient management of FMCFs that have been prioritized, it will be possible to identify vulnerabilities of safety valves and contribute to improving safety.

Preliminary Inspection Prediction Model to select the on-Site Inspected Foreign Food Facility using Multiple Correspondence Analysis (차원축소를 활용한 해외제조업체 대상 사전점검 예측 모형에 관한 연구)

  • Hae Jin Park;Jae Suk Choi;Sang Goo Cho
    • Journal of Intelligence and Information Systems
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    • v.29 no.1
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    • pp.121-142
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    • 2023
  • As the number and weight of imported food are steadily increasing, safety management of imported food to prevent food safety accidents is becoming more important. The Ministry of Food and Drug Safety conducts on-site inspections of foreign food facilities before customs clearance as well as import inspection at the customs clearance stage. However, a data-based safety management plan for imported food is needed due to time, cost, and limited resources. In this study, we tried to increase the efficiency of the on-site inspection by preparing a machine learning prediction model that pre-selects the companies that are expected to fail before the on-site inspection. Basic information of 303,272 foreign food facilities and processing businesses collected in the Integrated Food Safety Information Network and 1,689 cases of on-site inspection information data collected from 2019 to April 2022 were collected. After preprocessing the data of foreign food facilities, only the data subject to on-site inspection were extracted using the foreign food facility_code. As a result, it consisted of a total of 1,689 data and 103 variables. For 103 variables, variables that were '0' were removed based on the Theil-U index, and after reducing by applying Multiple Correspondence Analysis, 49 characteristic variables were finally derived. We build eight different models and perform hyperparameter tuning through 5-fold cross validation. Then, the performance of the generated models are evaluated. The research purpose of selecting companies subject to on-site inspection is to maximize the recall, which is the probability of judging nonconforming companies as nonconforming. As a result of applying various algorithms of machine learning, the Random Forest model with the highest Recall_macro, AUROC, Average PR, F1-score, and Balanced Accuracy was evaluated as the best model. Finally, we apply Kernal SHAP (SHapley Additive exPlanations) to present the selection reason for nonconforming facilities of individual instances, and discuss applicability to the on-site inspection facility selection system. Based on the results of this study, it is expected that it will contribute to the efficient operation of limited resources such as manpower and budget by establishing an imported food management system through a data-based scientific risk management model.