• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.10
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• pp.719-724
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• 2016

This paper describes the performance improvement of an inrush current limiter to prevent damage or malfunctions in power converters due to the inrush current. When the power converter of military radar is operated, the circuit breaker of the power converter is often activated because the overcurrent flows through the circuit breaker of the power converter. Therefore, this study performed a cause analysis of the problem, which is a larger current flow than the intended current(250A). The operation principle of an inrush current limiter and SCR (Silicon Controlled Rectifier) used in the inrush current limiter was analyzed. As a result, the overcurrent flow through the circuit breaker was found to be due to dv/dt triggering of SCR. Based on cause analysis, this paper proposes a technique by adding the resistor in front of the SCR to prevent an unnecessary inrush current. Finally, the effectiveness of the improvement was verified by measuring the output current in the inrush current limiter. The power converter equipped with the improved inrush current limiter operated for more than 1 year without the circuit breaker of the power converter being activated.

• Korean Journal of Construction Engineering and Management
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• v.20 no.6
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• pp.44-56
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• 2019

Recently, the paradigm of SOC investment has shifted from new construction to maintenance. This shift became more important for the highway system because it is as one of the most important SOC. In Korea, highway maintenance costs are about 20% of the total annual highway construction budget, which is about two-thirds of developed countries. In addition, establishing standardized guidelines for the highway maintenance operation is not in place. Therefore, in order for domestic road construction and maintenance technology to secure competitiveness in the global construction market, it is urgent to improve the management capacity for maintenance as well as the technology and management capacity. This study examines highway maintenance practices in OECD countries such as North America, Europe, Australia, New Zealand, and Japan to identify core elements of highway maintenance practice. It is imperative to establish a comprehensive management system based upon asset management principle. Even if the budget for the highway construction is reduced, investment in maintenance needs to be maintained.

• Korean Journal of Heritage: History & Science
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• v.46 no.1
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• pp.346-361
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• 2013

Since the Ming Castle located in Nanjing was designated by the Government of China as a cultural property in 1988, the Nanjing city government has been conserving the castle according to its plan and thus restoring the historical and cultural values of Nanjing. The project is still in progress, and in this regard, a series of logistics have formulated and a lot of discussions have taken place. Likewise, Korea has been carrying out multidirectional policies to conserve and utilize castles lying throughout the country, appreciating the historical and cultural resources of castles lying throughout the country, and at the same time gets down to designation as the World Heritage. This study focused on how Nanjing, not only a castle city but also a historical city, had established a principle and legal foundation regarding the protection of the Ming Castle, especially on how the problems, which might continually arise in a process where a scheme reached a working stage, had been solved. The problem-solving process is expected to have great implications for Korea in a similar situation. Hereat, this study analyzed the project plans formulated seasonally and gathered data on practical operation by conducting interviews with hands-on workers. The results showed that Nanjing had carried out policies to utilize the castles as tourism resources by harmonizing cityscape and ecological environment, but that it well conserved castles without damaging cultural assets. The stereoscopic protection system for the Ming Castle, based on the consideration of historical and cultural environments, may provide practical and useful data for Korea's administration mapping out for a castle conservation policy and designation as the UNESCO World Heritage.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.4
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• pp.449-455
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• 2019

This paper proposes a flyback diode of bridgeless PFC converter as SiC SBD (Schottky Barrier Diode) to achieve high efficiency. In addition, through the explanation of the operation principle of the bridgeless PFC converter, the conduction section of the freewheel diode is shown in the bridgeless PFC converter to verify the contribution of system loss due to the loss of the freewheel diode. The advantages of the SiC SBD device's physical properties and the reverse recovery characteristics are explained, and the efficiency is measured by measuring the turn-on and turn-off losses. The loss was calculated. The simulation results were calculated in consideration of device characteristics and verified through the waveform analysis and comparison of the actual system. In order to consider the device characteristics, the simulation was conducted using the thermal module of PSIM. As a result of the prototype test, the turn-on loss was 0.608W and the turn-off loss was 21.62W, resulting in the total switching loss of 22.228W. The comparison of the two results proved the validity of the experimental method. In addition, a high efficiency of 94.58% is achieved.

• Journal of Legislation Research
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• no.54
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• pp.111-154
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• 2018

The protection of fundamental rights of people is a natural duty of a state. Since Constitutional Law declare that a state is obliged to protect the fundamental rights of people obviously, it is reasonable to postulate that a state has a duty to protect every person's right much more positively. Of course, it is true that whereas right of freedom is much more important in modern states, the social right becomes more important currently. Nevertheless, we have no choice but to put an emphasis on the importance of the right of freedom like modern states. Thus states are still bound to try to protect the right of people, specific duty of behavior for the sake of right of freedom belongs to states. In particular, due to the fact that lifts are essential to our comfortable life and the demage from the accident concerning with the lifts is fatal, the strategy for securing the safety of using the lifts is significant to some extent. And because it is true that the experience of UK that put an emphasis on the role of civil actors is meaningful to us, there seems implications for us. Accordingly, it is possible to consider the material components such as the check of safety before installation for the sake of safety enhancement, quality control for lifts parts, specification of check criterion and variation of check cycle etc. and personal ones such as specification of qualification of competent persons, guarantee of competent person's independence, variation of obligator's duty and variation of user's obligation etc. However, as the situation of UK is one thing and that of Korea is another, we don't have to adhere to the policy and the experience of UK strictly. Rather, we had better apply the policy and experience of UK to ours appropriately.

• Korean Journal of Labor Studies
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• v.23 no.1
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• pp.85-127
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• 2017

Due to the management innovation policy that was introduced to governmentsupported research institutes (GSRI) in 1998, their employment structure has been continuously changing, with the most notable increase of the number of non-standard researchers and the diversification of employment contracts. This paper examines changes in the employment structure of GSRI over the last 20 years in relation to the introduction and operation of the PBS (project base system), which is a main factor that fundamentally changed the employment structure of research institutes. This paper purposes to analyze the current status of non-standard workers in the science and technology research area through interviewing standard and non-standard researchers. Under the PBS as a principle of organizing their research project, the project-managers cannot help but exploit non-standard researchers to process research within a tight budget. This structure of organizing research projects reinforces the increase of the number of non-standard researchers and diversification of non-standard employment relations. In addition, the wage and working conditions of non-standard workers are getting aggravated in this structure. Considering the characteristics of research institutes, precarious status of non-standard researchers will have negative effects on the development of science and technology.

• Korean Journal of Heritage: History & Science
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• v.54 no.1
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• pp.184-205
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• 2021

Governance is valued as a new concept and principle of social operation and public policy management, and its influence is gradually expanding. Among the various governance theories being put into practice and in case analysis studies, collaborative governance embracing various governance concepts has been found to increase interdependence and responsibility beyond participation and compromise, and create new public values by integrating and utilizing optimal social coordination forms. In the field of cultural assets, governance-related research is also being conducted for the efficiency, sustainability, and scalability of public policy enforcement. This study explored the government's role (promotion, arbitration, and condition creation) in collaborative governance, focusing on the "Cultural Heritage Guardians" to understand how collaborative governance operates in the cultural heritage sector. Regarding governance policies in the cultural asset sector, the cultural asset guardians highlighted the status, role, and characteristics of policies by examining their introduction, development, and implementation. The results of the analysis revealed that private-led, horizontal public-private cooperation, collaborative governance, policy introduction, solidarity, professionalism, resource/knowledge imbalance, cooperation precedence, etc., facilitate increased participation. The government has accordingly proposed measures to establish comprehensive legal stability centered on cooperation; strategic reorganization of dedicated organizations; strengthened, supportive intermediate organizations; and individual and multi-party consultative bodies.

• Journal of the Korea Convergence Society
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• v.13 no.3
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• pp.125-131
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• 2022

Recently, the prevalence of remotely managed patient care systems in medical institutions is increasing due to COVID-19. In particular, in the case of fluid monitoring, hospitals are considering introducing it as a system that can reduce patient safety and nurses' work. There are two products under development: a load cell method that measures weight and a method that detects drops of sap by infrared sensing. Although each product has differences in operation principle, sensor type, size, usage, and price, medical institutions are highly interested in the accuracy of the data obtained.In this study, two prototypes with different sensor methods were manufactured and the total amount of infusion per hour was measured to test the accuracy, which is the core of the infusion monitoring device. In addition, when there was an external movement, the change in the measured value of the sap was tested to evaluate the accuracy according to the measurement method. As a result of the experiment, there was a difference of less than 5% in the measurement value error of the two devices, and the load cell method showed a difference in the low-capacity measurement value and the infrared method in the high-capacity measurement value. As a result of this experiment, there was little difference in accuracy according to the sensor method of the infusion monitoring device, and it is considered that there is no problem in accuracy when used in a medical institution.

• Journal of Gastric Cancer
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• v.22 no.2
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• pp.94-106
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• 2022

Purpose: Laparoscopic proximal gastrectomy with double-tract reconstruction (LPG-DTR) is a function-preserving procedure performed for treating upper early gastric cancer (EGC). However, few studies have compared the outcomes of LPG-DTR with those of laparoscopic total gastrectomy (LTG). This study aimed at comparing the short-term outcomes of LPG-DTR between LTG and upper EGC. Materials and Methods: For upper-third EGC, a multicenter, prospective, randomized trial was performed to compare those who underwent LPG-DTR with those who underwent LTG. Short-term outcomes, including clinicopathologic results, morbidity, mortality, and postoperative courses, were evaluated using a full analysis set based on the intention-to-treat principle and the per-protocol set. Results: Of the patients, 138 who fulfilled the criteria were randomized to each group. One patient in the LPG-DTR group withdrew consent. Sixty-eight patients underwent LPG-DTR and 69 underwent LTG. The operative time (LPG-DTR=219.4 minutes; LTG=201.8 minutes; P=0.085), estimated blood loss (LPG-DTR=76.0 mL; LTG=66.1 mL; P=0.413), and the morbidity rate (LPG-DTR=23.5%; LTG=17.4%; P=0.373) between the groups were not significantly different. No mortality occurred in either of the study groups. Two weeks post operation, the Visick scores for postprandial symptoms, including reflux symptoms, were not significantly different between the groups (P=0.749). Laboratory findings on postoperative day 5 were not significantly different between the groups. Conclusions: The short-term outcomes of LPG-DTR for upper EGC were comparable to those of LTG.

• Journal of Korea Entertainment Industry Association
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• v.14 no.3
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• pp.117-132
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• 2020

The purpose of this study is to examine the lifelong education policy in Korea and Germany, focusing on the historical transition process, and to explore desirable ways to develop the lifelong education policy in Korea. To this end, We compared and analyzed Korea and Germany's lifelong education policy using research papers on lifelong education and practical data published by BMBF, DIE, DVV, EAEA, UIL, and NILE. As a result of the study, German lifelong education policy has improved social and vocational professionalism running programs suitable for the characteristic of region, Korean lifelong education policy lacks civic education in terms of local lifelong education due to political sensitivity. In addition, Germany is expanding the participation rate of lifelong education by constructing an environment where it is easy to participate in lifelong education, while Korea's participation rate in lifelong education is lower than that of advanced OECD countries. At last, the German lifelong education policy pursues a natural change in the needs of the society, the ideological principle of which require education be independent. On the other hand, the study confirms that Korean lifelong education policy tends to be controlled by the central government. As a result of this study, Germany's lifelong education policy provide the following implications for Korea's lifelong education policy. First, This dissertation emphasizes the need for the learner-centered operation as the needs of educational consumers become more diverse. Secondly, It highlights the need for activation of lifelong education in career education. Third, The expansion of the lifelong education budget to support good quality lifelong learning. Fourth, Holistic and long-term system for sustainable lifelong learning society needs to be structured.