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Bayesian Network-based Probabilistic Safety Assessment for Multi-Hazard of Earthquake-Induced Fire and Explosion (베이지안 네트워크를 이용한 지진 유발 화재・폭발 복합재해 확률론적 안전성 평가)

  • Se-Hyeok Lee;Uichan Seok;Junho Song
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.37 no.3
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    • pp.205-216
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    • 2024
  • Recently, seismic Probabilistic Safety Assessment (PSA) methods have been developed for process plants, such as gas plants, oil refineries, and chemical plants. The framework originated from the PSA of nuclear power plants, which aims to assess the risk of reactor core damage. The original PSA method was modified to adopt the characteristics of a process plant whose purpose is continuous operation without shutdown. Therefore, a fault tree, whose top event is shut down, was constructed and transformed into a Bayesian Network (BN), a probabilistic graph model, for efficient risk-informed decision-making. In this research, the fault tree-based BN from the previous research is further developed to consider the multi-hazard of earthquake-induced fire and explosion (EQ-induced F&E). For this purpose, an event tree describing the occurrence of fire and explosion from a release is first constructed and transformed into a BN. And then, this BN is connected to the previous BN model developed for seismic PSA. A virtual plot plan of a gas plant is introduced as a basis for the construction of the specific EQ-induced F&E BN to test the proposed BN framework. The paper demonstrates the method through two examples of risk-informed decision-making. In particular, the second example verifies how the proposed method can establish a repair and retrofit strategy when a shutdown occurs in a process plant.

Theoretical analysis of erosion degradation and safety assessment of submarine shield tunnel segment based on ion erosion

  • Xiaohan Zhou;Yangyang Yang;Zhongping Yang;Sijin Liu;Hao Wang;Weifeng Zhou
    • Geomechanics and Engineering
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    • v.37 no.6
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    • pp.599-614
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    • 2024
  • To evaluate the safety status of deteriorated segments in a submarine shield tunnel during its service life, a seepage model was established based on a cross-sea shield tunnel project. This model was used to study the migration patterns of erosive ions within the shield segments. Based on these laws, the degree of deterioration of the segments was determined. Using the derived analytical solution, the internal forces within the segments were calculated. Lastly, by applying the formula for calculating safety factors, the variation trends in the safety factors of segments with different degrees of deterioration were obtained. The findings demonstrate that corrosive seawater presents the evolution characteristics of continuous seepage from the outside to the inside of the tunnel. The nearby seepage field shows locally concentrated characteristics when there is leakage at the joint, which causes the seepage field's depth and scope to significantly increase. The chlorine ion content decreases gradually with the increase of the distance from the outer surface of the tunnel. The penetration of erosion ions in the segment is facilitated by the presence of water pressure. The ion content of the entire ring segment lining structure is related in the following order: vault < haunch < springing. The difference in the segment's rate of increase in chlorine ion content decreases as service time increases. Based on the analytical solution calculation, the segment's safety factor drops more when the joint leaks than when its intact, and the change rate between the two states exhibits a general downward trend. The safety factor shows a similar change rule at different water depths and continuously decreases at the same segment position as the water depth increases. The three phases of "sudden drop-rise-stability" are represented by a "spoon-shaped" change rule on the safety factor's change curve. The issue of the poor applicability of indicators in earlier studies is resolved by the analytical solution, which only requires determining the loss degree of the segment lining's effective bearing thickness to calculate the safety factor of any cross-section of the shield tunnel. The analytical solution's computation results, however, have some safety margins and are cautious. The process of establishing the evaluation model indicates that the secondary lining made of molded concrete can also have its safety status assessed using the analytical solution. It is very important for the safe operation of the tunnel and the safety of people's property and has a wide range of applications.

Research on the Transition Process of University Lifelong Education System Support Project (대학 평생교육체제 지원사업 사업의 변천과정 연구)

  • Bog Im Jeong;Tae Hui Kim
    • The Journal of the Convergence on Culture Technology
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    • v.10 no.2
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    • pp.273-278
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    • 2024
  • The purpose of this study is to examine the limitations of university operating system changes as a result of the policy changes and outcomes of the university lifelong education system support project by project period, and based on this, to propose a development plan to support the university's adult learning system. In this study, we sought to investigate changes in the higher education environment and changes in lifelong education in universities through analysis of literature and various data. The changing times of technological innovation and changes in knowledge require continuous learning even after school education, and the need for re-education and improved education is increasing. Therefore, the Ministry of Education and the National Institute for Lifelong Education have been actively carrying out support projects for lifelong learning-centered universities since 2008 to provide adult learners with opportunities to study. This project is centered around universities and the local community, and is promoting various types of changes in educational operation, such as reforming the university's academic system to be adult-friendly and operating night or weekend classes in order to provide educational opportunities for adult learners. Now, universities must play a role as a hub of regional lifelong education for the coexistence of the region and university, and as a key institution responsible for the contemporary tasks of sustainable development and coexistence between the university and the community.

Case study on identity development of mathematics teachers involved in learning community: Based on the theory of "Community of Practice" (학습공동체에 참여한 수학교사의 정체성 형성 과정에 대한 사례연구: 실천공동체 이론을 중심으로)

  • Yoon, Jungeun;Kwon, Oh Nam
    • Communications of Mathematical Education
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    • v.38 no.1
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    • pp.1-26
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    • 2024
  • As the limitations of professional development programs and individual attempts to improve teaching expertise have been reported, mathematics teachers have operated various types of teacher learning communities as alternative teacher professional programs. A teacher learning community can be considered a Community of Practice(CoP) in that it satisfies three factors of Cop, which are common purpose, mutual participation, and shared repertoire, so the 'learning' of a teacher community can be interpreted based on the theory of CoP. The purpose of this study is to investigate the process of identity development of five mathematics teachers who have been continuously involved in teacher communities. For this, the researcher collected data on the entire process of community activities through participant observation and conducted individual follow-up interviews to explore mathematics teachers' narratives and personal experiences. Results indicated that mathematics teachers experienced the development of practical knowledge related to mathematics teaching and learning, improvement of teaching practice through continuous reflection and introspection, and recognization the shared value of togethering through community immersion. Based on these experiences, implications for the effective operation of learning communities such as national support of teacher learning communities and horizontal and cooperative teacher norms were discussed, and follow-up research was proposed.

A Study on Establishment of Technical Guideline of the Installation and Operation for the Efficient Bio-gasification Facility of Pig Manure and Food Waste(II): - Results of the Precision Monitoring - (가축분뇨 병합처리 바이오가스화를 위한 설계 및 운전 기술지침 마련 연구(II) - 정밀모니터링 결과 중심으로 -)

  • Lee, Dongjin;Moon, HeeSung;Son, Jihwan;Bae, Jisu
    • Journal of the Korea Organic Resources Recycling Association
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    • v.25 no.3
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    • pp.91-98
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    • 2017
  • The purpose of this study is to provide a design and operation technical guideline for meeting the appropriate design criteria to bio-gasification facilities treating organic wastes. 9 anaerobic digestion facilities which is normally operated during the field survey and 14 livestock manure farms were selected for precision investigation. the physicochemical analysis was performed on the moisture and organic contents, nutrients composition (carbohydrate, fat, protein), volatile fatty acids (VFAs), and nitrogen, etc. Volatile solids (VS) of organic wastes brought into the bio-gasification facilities were 2.81 % (animal manure only) and 5.92 % (animal manure+food waste), respectively. Total solids (TS) reults of samples from livestock farms were 5.6 % in piglets and 11~13 % in other kinds of breeding pigs. The actual methane yield based on nutrients contents was estimated to $0.36Sm^3CH_4/kgVS$ which is equivalent to 72 % of theoretical methane yield value. The optimum mixing ratio depending on the effect of the combined bio-gasification was obtained through the continuous stirred-tank reactor (CSTR) which is operated at different mixing ratio of swine manure and food waste leachate. The range of swine manure and food waste leachate from 60:40 to 40:60 were adequate to the appropriate conditions of anaerobic digestion; less than 100 gTS/, more than alkalinity of 1 gCaCO3/L, C/N ratio 12.0~30.0, etc.

Studies on Sanitary Conditions in a Special Grade Chicken Processing Plant in Korea I. Storage Period of Packed Chicken Meat in relation to the Bacterial Contamination of Each Processing Part (특급도계장의 위생실태에 관한 연구 I. 작업부분별 세균오염도 측정)

  • 오경록
    • Korean Journal of Poultry Science
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    • v.13 no.1
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    • pp.41-48
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    • 1986
  • In order to investigate the storage period of packed chicken meat in relation to the bacterial contamination of each processing part, a special grade poultry processing plant located at Dongdoochun-City, Gyeonggi-Do, was surveyed mainly in point of sanitary conditions. The results are summarized as follows. 1. processing room near reception and packing room next to shipping area showed the highest bacterial counts in air. 2. Equipments and instruments for slaughtering also showed a high degree of bacterial contamination even before the operation. This finding suggested that the possibility of the bacterial contamination of carcasses through equipments and instruments would be high, if the continuous sanitary control measures are not properly taken. 3. The bacterial count of scalding water was 3${\times}$10$\^$7/ for standard plate count and 4${\times}$10$\^$5/ for most probable number of coliform bacteria at 1 hour after the start of operation. These values were maintained until the completion of processing. 4. At the ending of chilling process, the bacterial counts of chilling water were 3.3 ${\times}$10$^4$ and 3.0${\times}$10$^3$for standard plate count, when the volume of water used per bird were 21 and 51, respectively. Bacterial contamination was further decreased about 10$\^$-3/-10$\^$-4/ times as the effective chlorine concentration in chilling water was maintained about 50 ppm. 5. An average standard plate count of the residual water In abdominal cavity of carcasses was 3.9${\times}$10$^4$immediate after chilling, however, it increased to 4.7${\times}$10$\^$7/ when the carcasses were packed and stored for 10 days at 4$^{\circ}C$. off-odour development was observed as the bacterial count was not less than 10$\^$6//$m\ell$ of the residual water of the packed carcasses. Data indicated that if the standard plate count of the residual water in abdominal cavity of carcasses was not less than l0$^4$immediate after chilling, the packed chicken meat would not be stored longer than 5 days at 4$^{\circ}C$.

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Demonstration-scale Offshore CO2 Storage Project in the Pohang Basin, Korea (포항분지 해상 중소규모 CO2 저장 실증연구)

  • Kwon, Yi Kyun
    • The Journal of Engineering Geology
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    • v.28 no.2
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    • pp.133-160
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    • 2018
  • $CO_2$ storage is a very important technology for reduction of greenhouse gas emissions and has been considered as almost the only viable and effective option for immediate large-scale $CO_2$ sequestration. Small-scale demonstration project for offshore $CO_2$ storage in the Pohang Basin is the transitional stage R&D program for technological preparation of large-scale $CO_2$ storage project in Korea. Through the extensive exploration research for prospective $CO_2$ storage sites, the offshore strata in the Pohang Basin was recommended for the storage formation of the small-scale demonstration project. The Pohang Offshore Storage Project launched at 2013, and has accomplished the technical demonstration and technological independence in a wide range of $CO_2$ storage technology, such as geophysical exploration, storage site characterization, storage design, offshore platform construction, injection-well drilling and completion, deployment of injection facility, operation of $CO_2$ injection, and $CO_2$ monitoring. The project successfully carried out $CO_2$ test injection in early 2017, and achieved its final goal for technical development and demonstration of $CO_2$ storage in Korea. The realization of $CO_2$ injection in this project is the measurable result and has been recorded as the first success in Korea. The Pohang Offshore Storage Project has a future plan for the continuous operation of $CO_2$ injection and completion of $CO_2$ monitoring system. The project has provided in-house technical and practical expertises, which will be a solid foundation for the commercial-scale $CO_2$ storage business in Korea. Additionally, the project will help to secure national technical competitiveness in growing international technology market for $CO_2$ storage.

Evaluation of Oral Health Promotion Program Connected with Hypertension and Diabetes Management Programs: Use of a Logical Model (일부 보건소 고혈압·당뇨관리교실 연계 구강건강증진 프로그램 운영 및 평가: 논리적 모형을 이용하여)

  • Yoo, Sang-Hee;Shin, Bo-Mi;Bae, Soo-Myoung;Shin, Sun-Jung
    • Journal of dental hygiene science
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    • v.16 no.4
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    • pp.293-301
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    • 2016
  • This study aimed to design and operate a complementary integrated health management program based on the connection between the hypertension and diabetes management programs and the oral health programs at a public health center. It also proposed to suggest the phased evaluation indicators. In this study, 48 adults registered in the hypertension and diabetes management program were selected from the Gangneung public health center. The clinic-specific programs were led by dental hygienists and operated for visitors twice every two weeks. The programs were designed based on the logical model, and indicators for evaluating the structure, process, and outcome were presented and applied to the input, process, output, and outcome. The evaluation indices consisted of quantitative and qualitative indicators, and the planning and operation, goal achievement, and effect of each program were assessed. The process evaluations were assessed by the appropriateness of the managers and the operating fidelity of the programs. Indicators for evaluating the outcomes were gingival bleeding, oral health knowledge, oral health awareness, and the satisfaction of the participant and the manager. The clinic-specific programs resulted in positive changes in the evaluated outcomes. The integrated health management of visitors to the hypertension and diabetes management program is important as the general and oral health has common risk factors. Furthermore, long-term operation and continuous monitoring of oral health programs are necessary to evaluate the common factors in chronic disease management.

Local Autonomy, National Economy and Local Public Finance (지방자치(地方自治)와 국민경제(國民經濟) 및 지방재정(地方財政))

  • Lee, Kye-sik
    • KDI Journal of Economic Policy
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    • v.13 no.2
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    • pp.41-67
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    • 1991
  • Local autonomy of Korea's lower-level local council has been reinstated following elections last March for the first time in thirty years. Last June, we had elections for the upper-level local council. Mayors, governors, and administrative chiefs of cities, provinces and other local government bodies are slated for elections in the first half of next year. The impacts of local autonomy are taking effect in not only the political sphere, but also the administrative and economic spheres. In fact, it seems that some modification of all economic policy making and administration is inevitable. Since the initiation of local autonomy, in order to make the economy work more efficiently, it has become quite important to examine the impact of local autonomy on the national economy. The areas of local autonomy include independent legislative power, administrative power, organizational power, and most important of all, the independent public financial power of the local governments. The purpose of this paper is to examine the effects of local autonomy on the national economy and ways of enhancing the role of local public finance to facilitate settlement and development of the local autonomy system. Local autonomy will contribute to the continuous growth of our economy, allow balanced development, and generate greater efficiency. However, local autonomy can also incur economic costs causing at times short-term price instability, inefficient resource allocation, through tax competition and tax exporting, and insolvency of local government due to abusive fiscal operation. To reduce these side effects, different alternatives must be considered. Local autonomy systems generally provide more efficient resource allocation than centralization. But in the model used in Chapter 3 of this paper, the relative efficiencies of both local autonomy and centralization are determined by comparing the elasticity of substitution between national public goods and local public goods. If the elasticity of substitution is bigger than one, centralization provides a more efficient resource allocation. The development of local autonomy could be attained through democratization of the local public finance system including the following three propositions. I) The independence of public financial power of local governments should be established over central government. Furthermore, a democratically operated scheme of intergovernmental fiscal coordination is especially necessary. 2) In the operation of local finance, direct democracy is needed to induce the voluntary participation of local residents. The residents can take part in planning both the local budget and the development of the community. To attain this goal, all the results of local finance operations should be made public. 3) Among economic ill-effects of the local autonomy system, the most serious one is the possibility of insolvency of local governments. Therefore, measures to limit abusive spending by the local governments should be introduced, such as the fiscal restraints system adopted in the United States.

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Critical Pathway Development for the Hysterectomy Patients and its applied Effect (자궁적출술 환자를 위한 critical pathway 개발과 적용효과)

  • Noh, Gi-Ok;Park, Kyung-Sook
    • Women's Health Nursing
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    • v.6 no.2
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    • pp.234-257
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    • 2000
  • At present in the medical care, the study and effort for producing health service to consider efficiency, effectiveness, and quality are urgently called for because of the difficulty in the keen competition according to the inter- nationalization and opening, the operation in the medical institution service testing system, the change in the medical policy of KDRGs, and the lack of the health care cost increasing rate. As an alternative, the case management for the new management system is introduced in the U.S., and the Critical Pathway that is the method designing the contents of activity and its result has been developed and applied in order to anticipate and manage the patient-outcome for the realization of the cost-effective case-management. Thus, this study intended to analyze the effectiveness to obtain by developing the Critical Pathway presented as the method to improve the quality-betterment and cost effectiveness through the continuous and consistent patient management for the hysterectomy patient and applying it to the real practice. As a study method, this author formed a conceptual framework through considering five Critical Pathway used in the current U.S. and three Critical Pathway presented in the literature to develop the Critical Pathway for the hysterectomy patient, and made out the preliminary Critical Pathway through reviewing the old chart. This author made the verified the validity of the expert group about the developed Critical Pathway, and to confirm the possibility of practice application, completed and settled the final Critical Pathway after using the Critical Pathway to the hysterectomy patient from March 1st to 15th, 1997. Finally, to analyze the application-effect of the developed Critical Pathway, this author offered health care service applying the Critical Pathway to the hysterectomy patient from April 15th to August 31th, 1997. The guide for the Critical Pathway was carried out in advance by outpatient setting nurse for outpatient setting visit before the operation, and after hospitalization the primary nurse monitored the execution degree on the every duty. After discharge this author surveyed the complication through phone visiting, and one month after discharge surveyed the patient's reaction about the offered service when outpatient setting visit and analyzed the result. The source for health care cost was obtained by the statistics about the hospital charge which was offered by the General Business Department. The results were as follows. 1. It was decided that the vertical line of the Critical Pathway was made up of eight items such as monitoring/assessment, treatment, line/drains, activity, medication, lab test, diet, patient teaching, and the horizontal line of the Critical Pathway was made up of from hospitalization to discharge. 2. After the analysis of service contents through reviewing the old chart, it was decided that the horizontal line of the preliminary Critical Pathway was made up of from hopitalization to fourth postoperative day, and the vertical line of it was divided into eight items which were the contents to occur with the time frame of the horizontal line. 3. After the verifying the validity of the expert group about the preliminary Critical Pathway, the horizontal line was amended from hopitalization to third postoperative day, and taking their consensus, some contents of the horizontal line was amended and deleted. 4. From March 1st to 15th, 1997, to confirm the clinical suitability, this author offered eight hysterectomy patients the medical service through the Critical Pathway. The result was that three of them could be discharged at the expected discharge day, and the others later than that day. Supplementing the preliminary Critical Pathway through analyzing the cause of that delay- case, this author developed the final Critical Pathway. 5. There were no significant differences between the experimental and the control group in the incidence of complication(P > 0.05). 6. The 92.4% of experimental group was satisfied with the Critical Pathway service. 7. The length of hospital stay of the experimental group offered with the Critical Pathway service was 4.6 days and there was a significant difference that it was 1.3 days shorter than that of the control group(t=-29.514, P=0.000). 8. There wsa a significant difference that the mean medical charge per one patient of the experimental group offered the Critical Pathway service was cheaper \124,150 than that of the control group(t=-9.826, P=0.000). 9. The result that the author assumed and analyzed hospital income with the rate of turning bed was assumed that the increase of hospital income was \63,245,072 for that study, and the income increase was expected with \68,704,864 for a year. The result that this author applied the Critical Pathway to the hysterectomy patient have no differences in the incidence of complication, high satisfaction with that service, and the length of hospital stay decreased in the experimental group, and the mean hospital charge per one patient decreased, but hospital income increased. Suggestions for further study and nursing practice are as follows. 1. The study to apply the Critical Pathway for a year, verify the validity, and measure the effect repeatedly is needed. 2. To apply and manage the Critical Pathway effectively, the study to computerize it is needed. 3. The study to develop hospital-based Critical Pathway about other diseases or procedure, and measure the effect is needed.

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