• Journal of Intelligence and Information Systems
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• v.14 no.1
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• pp.117-129
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• 2008

The cost-based scheduling work has been done in both the Operations Research (OR) and Artificial Intelligence (AI) literature. To deal with more realistic problems, AI-based heuristic scheduling approach with non-regular performance measures has been studied. However, there has been little research effort to develop a full inter-job cost propagation algorithm (CPA) for different jobs having multiple downstream and upstream activities. Without such a CPA, decision-making in scheduling heuristics relies upon local, incomplete cost information, resulting in poor schedule performance from the overall cost minimizing objective. For such a purpose, we need two types of CPAs : intra-job CPA and inter-job CPA. Whenever there is a change in cost information of an activity in a job in the process of scheduling, the intra-job CPA updates cost curves of other activities connected through temporal constraints within the same job. The inter-job CPA extends cost propagation into other jobs connected through precedence relationships. By utilizing the cost information provided by CPAs, we propose cost-based scheduling heuristics that attempt to minimize the total schedule cost. This paper develops inter-job CPAs that create and update cost curves of each activity in each search state, and propagate cost information throughout a whole network of temporal constraints. Also we propose various cost-based scheduling heuristics that attempt to minimize the total schedule cost by utilizing the cost propagation algorithm.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.5
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• pp.506-515
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• 2016

The purpose of this study was to identify the factors associated with the levels of depression of the elderly (living in urban areas). Interviews were performed during the period from July 1, 2015 to August 31, 2015 of 386 elderly people in urban areas. The mean score of depressive symptoms was significantly higher in the subjects of higher age, lower educational level, living alone, having a lower monthly income, relying on government subsidy for their living expenses, having a chronic illness, lower state of subjective health, without regular exercise, poorer subjective sleeping time, lower frequency of going out, irregular eating habits, depending on some level of help for their ADL and IADL, and having lower self-esteem and social support. The depressive symptoms showed a meaningful positive correlation with ADL and IADL and a negative correlation with self-esteem and social support. On multiple regression analysis, the meaningful variables related to their depressive symptoms were their education, monthly income, subjective health status, ADL, self-esteem, and social support. Also, according to the variables was 54.1% of depressive symptoms. Therefore, it is considered that the practice of physical and mental health care, as well as social support, is required to reduce the level of depression in the elderly.

• Journal of Information Management
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• v.39 no.1
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• pp.83-108
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• 2008

This thesis investigated disabled students' actual status of applying for university libraries. This thesis investigated how many times the university disabled students utilized the libraries, if facilities, apparatuses, materials, and regular employees were operated properly, and if they were established actually on the target at thirty private university libraries located at Seoul and Gyeonggi regions in operation of specially screening the objective students for special education in 2008. The investigation found that the general operation level of university libraries for disabled students were less than "medium"(average 2.38). As for utilization ratio, the most university students responded that "they didn't utilize libraries so many times(60%)". As for the response ratio of university library facilities and services, the most university students responded, "very insufficient", 99 items(32.27%), and the least university students responded, "very excellent", 28 items(7.0%). On the other hand, as for the analysis of each field, building facilities, in all of the items, were established more than "medium"(average 3.26), but material preparation level(average 1.8 point), employee education for softly supporting disabled students, and library utilization education on the target at disabled students(average 1.87) were less than "insufficient". Especially, the field of service was "insufficient level"(average 2.48), and standard deviation was more than 1.4. Manpower stationing and material delivery services have the biggest standard deviation between universities. So, this investigation found that university libraries reformed access to facilities a lot, but that its level of fundamental policy for library, such as materials, manpower, and the education on utilization, were in insufficient level.

• Journal of the Korean Recycled Construction Resources Institute
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• v.7 no.3
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• pp.224-234
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• 2019

Waterproof layers are installed in civil engineering structures and bridge construction is commonly finished by applying a layer of regular or asphalt concrete above the waterproof layer. However, asphalt materials are susceptible to melting at high temperature due to its superior temperature sensitivity, and this causes the waterproofing material to melt due to the high temperature of the asphalt concrete, thereby increasing the defect occurrence rate due to the thickness reduction. In this study, tensile strength and elongation of hard and soft type of MMA(Methyl Methacrylate) applied to bridges were compared in accordance to standard performance criteria based on different mixture ratios. Results of comparative testing showed that hard MMA resin can display a satisfactory tensile strength, and soft MMA resin displays satisfactory elongation properties, but as the two resin types are separately used, neither types are able to satisfy the standard requirements outlined in KS F 4932. When the amount of the powder exceeds 56.25% of the total amount, voids are generated on the surface after curing and self leveling was impossible and a heterogeneous surface is formed. Furthermore, when the hard resin: soft resin: powder mixture ratio was set to 15g: 85g: 150g. the tensile strength was $1.5N/mm^2$ and the elongation percentage was 133% which satisfy the tensile performance of KS F 4932.

• Journal of the Korea Convergence Society
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• v.12 no.12
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• pp.315-322
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• 2021

This study analyzes the Required Safe Egress Time (RSET), in the event of a fire at a welfare center for the disabled, using the emergency passage according to the floor arrangement of users to evaluate the safety and the difference in RSET for each emergency passage using the Pathfinder simulation program to suggest an efficient evacuation method. As a result of RSET, it was found that there is no problem in evacuation safety for the current state of the facility's personnel allocation by satisfying the standard RSET in case of fire, and evacuation can be completed safely by evacuating through stairs rather than using elevators if possible. It is necessary for employees to be provided sufficient education and training in advance so that they can evacuate effectively with the disabled in case of fire. This study gives significance in saving many precious lives and safely evacuate in case of fire as evacuation routes were secured through the design, construction and operation of facilities for the disabled and the RSET was shortened through regular evacuation practices. It is necessary to discuss the further RSET studies based on the automatic fire shutters open or not when a fire occurs at a specific location following the installation of automatic fire shutter at the entrance of each floor of the facilities.

• Journal of agricultural medicine and community health
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• v.46 no.2
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• pp.67-77
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• 2021

Objectives: This study aimed to identify the vaccination rate for pneumococcus among aged 65 or older, and at the same time to determine the reasons for vaccination or non-vaccination. Methods: The population of this study was aged 65 or older, with a total of 1,150 subjects to be analyzed and a computer assisted telephone interviewing was used. The survey included pneumococcal vaccination status, reasons of vaccination, sources of information on vaccination, reasons for not vaccination, and other related factors. Results: The vaccination rate for pneumococcus among aged 65 or older was 56.2 percent, lower than 69.0 percent in the U.S. (2017), and 69.2 percent in the U.K. (2019). Among the factors related to the pneumococcal vaccination, the groups with the high vaccination rate were women, low age groups, residents of urban areas, people without a job, people with high education, medical insurance subscribers, married people, and people who have family members. In addition, the groups with high vaccination rates were those with high awareness, those who received recommendations from doctors, those who had vaccination records, those who believed in vaccination effects, and those who saw public service advertisements. Conclusions: In the future, it is necessary to develop alternatives to accurately manage vaccination records for adults who are not eligible for state support, and regular adult vaccination rates should be calculated so that they can be used as evidence for the country's infection control policy.

• Korean Journal of Labor Studies
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• v.19 no.1
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• pp.177-211
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• 2013

The Chinese dual structure of employment('Shuangguizhi') has been retained through the Economic Reforms, and has been supported and reproduced by the system of division between rural and urban household registration. In the 2000s, efforts of the government to abolish the division appeared to be effective with the introduction of the 'Labor Contract Act'. However, the eclecticism of the Act and the outbreak of the global financial crisis in 2008 gave new momentum to the revival of the Chinese dual structure of employment by increasing the scale of labor dispatching. Labor dispatching in China has become a regular form of employment rather than an exceptional one. Labor dispatching reveals its Chinese characteristics against the particular background formed during the periods of state-owned-enterprise restructuring around 2000. The combined effects of the 'Labor Contract Act' and the global financial crisis brought about the effect of increase rather than control of labor dispatching, and gave a signal to enterprises to use various forms of labor dispatching including 'reverse directional labor dispatching' to lessen burdens and costs caused by the Act and the crisis. As labor dispatching strengthens or displaces the existing dual structure of employment, social groups which need more social protection tend to be much more excluded from the protection of the government and the society.

• Journal of Korea Entertainment Industry Association
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• v.15 no.1
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• pp.99-115
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• 2021

The aim of this study is to improve the curriculum of the physical education by recognizing the necessity of new physical education to meet the needs of the sports industry. As a preliminary study for this, the subjects of physical education at American universities and those at regular domestic universities have been investigated. Then, the current state of operation of the physical education system of the credit bank system has been investigated. The first is the definition of the credit banking system, the investigation of accreditation of credits and the institutions of education and training. The Second is the investigation of the educational goals and qualifications of each major in the standard education curriculum and the current status of accredited credits. The third is the type and operation of institutions by degree in physical education, and the survey on current majors in progress. The fourth is the survey on the current status of operating institutions by region. The fifth is the classification of detailed subjects by major and the survey on the status of subjects by major. The last is the detailed subjects by major, and the analysis of the consistent or similar subjects in domestic and international sports industry subjects. Through the findings of this investigation, the following directions for improvement of the credit bank system curriculum have been suggested. Firstly, it is necessary to newly establish major courses tailored to social change. Secondly, it is necessary to develop mandatory and optional courses that meet the needs of the times. Thirdly, it is necessary to increase courses centered on field training that can meet the needs of the sports industry. Fourthly, in relation to the evaluation and recognition of the credit banking system, the conclusion have been derived that institutional improvement should be urgently performed.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.2
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• pp.211-218
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• 2021

This paper addressed the problems of controlling the coupled pitch-roll motions in a marine vessel exposed to the regular waves in the longitudinal and transversal directions. Stabilization of the pitch and roll motions can be regarded as the essential task to ensure the safety of a ship's navigation. One of the important features in the pitch-roll motions is the resonance phenomena, which result in unexpected large responses in terms of pitch and roll modes in some specific conditions. Besides, owing to its inherent characteristics of coupled combination and nonlinearity of restoring terms, the vessel shows various dynamical behaviors according to the system parameters, especially in the pitch responses. Above all, it can be seen that suppression of pitch rate remains the most significant challenge to overcome for ship maneuvering safety studies. To secure the stable upright condition, a quasi-sliding mode control scheme is employed to reduce the undesirable pitch and roll responses as well as chattering elimination. The Lyapunov theory is adopted to guarantee the closed stability of the pitch-roll system. Numerical simulations demonstrate the effectiveness of the control scheme. Finally, the control goals of state convergences and chattering reduction are effectively realized through the proposed control synthesis.

• Journal of Navigation and Port Research
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• v.46 no.4
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• pp.367-374
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• 2022

The purpose of this study was to propose a deep learning algorithm that applies to the fault diagnosis of fuel pumps and purifiers of autonomous ships. A deep learning algorithm reflecting the time dependence of the measured signal was configured, and the failure pattern was trained using the vibration signal, measured in the equipment's regular operation and failure state. Considering the sequential time-dependence of deterioration implied in the vibration signal, this study adopts Conv1D with sliding window computation for fault detection. The time dependence was also reflected, by transferring the measured signal from two-dimensional to three-dimensional. Additionally, the optimal values of the hyper-parameters of the Conv1D model were determined, using the grid search technique. Finally, the results show that the proposed data preprocessing method as well as the Conv1D model, can reflect the sequential dependency between the fault and its effect on the measured signal, and appropriately perform anomaly as well as failure detection, of the equipment chosen for application.