• 대한예방의학회:학술대회논문집
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• 대한예방의학회 1994년도 교수 연수회(역학)
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• pp.270-284
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• 1994

Interim analyses of randomized trials enable investigators to make more efficient use of limited research resources and to satisfy ethical requirements that a regimen be discontinued as soon as it has been established to have an inferior efficacy/toxicity profile. Unfortunately. the integrity and credibility of these trials can be compromised if inappropriate procedures are used in monitoring interim data. 'In this paper we discuss how group sequential designs provide useful guidelines that enable one to satisfy the valid objectives of interim monitoring while avoiding undesirable consequences, and we consider how flexible one can be in the way such designs are implemented. We also provide motivation for the role of data-monitoring committees in preserving study integrity and credibility in either government- or industry-sponsored trials. In our view. these committees should have multidisciplinary representation and membership limited to individuals free of apparent significant conflict of interest, and ideally should be the only individuals to whom the data analysis center provides interim results on relative efficacy of treatment regimens. Finally. we discuss some important practical issues such as estimation following group sequential testing, anal ysis of secondary outcomes after using a group sequential design applied to a primary outcome, early stopping of negative trials. and the role of administrative analyses.

• 디지털산업정보학회논문지
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• 제8권3호
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• pp.33-39
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• 2012

Since the passing of the Personal Information Act in March 2011 and its initial introduction in September, over the one year to date diverse security devices and solutions have been flowing into the market to enable observance of the relevant laws. Beginning with security consulting, corporations and institutions have focused on technology-based business in order to enable observance of those laws competitively in accordance with 6-step key procedures including proposal, materialization, introduction, construction, implementation, and execution. However there has not been any investment in human resources in the field of education such as technology education and policy education relative to the most important human resources field nor investment in professionals in the organization for the protection of personal information or in human resources for operating and managing IT infrastructure for actual entire personal information such as special sub-organizations. In this situation, as one process of attracting change from the nature of the technology-based security market toward a professional human resource-based security infrastructure market, it is necessary to conduct research into standardization modeling concerning special organizational composition and a management system for the protection of personal information.

• 설비공학논문집
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• 제18권11호
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• pp.933-940
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• 2006

In this study multi-zone modeling program CONTAM 2.4 developed by NIST is used for estimating the air disinfection rate of the interior of a room which is set up the indoor air disinfection system with filter and ultra violet germicidal irradiation (UVGI). Developed models those enable to predict the transmission of air home contagion such as bacteria and fungus generated in our daily life are useful model for designning air cleaning & ventilation system of building. Also, results indicate that these models are enable to compute the real situation that is almost impossible of carrying out experiment in an actual condition due to biohazard problems and suggest that engineers will use these models as a design tool for the future immune building system.

• 비교문화연구
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• 제37권
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• pp.335-360
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• 2014

The purpose of this paper is to investigate whether high-level(level 6) essay-writing questions in Test of Proficiency in Korean (TOPIK) have been presented appropriately so as to enable foreign test-takers to display their Korean writing ability properly, and to provide some suggestions on how those questions need to be changed. To accomplish this purpose, all the essay-writing questions were collected from the 33 TOPIK tests, from the 2nd in 1998 to the 35thin 2014, and analyzed from the perspectives of their topics and formats. The results are that high-level TOPIK essay-writing questions showed a strong tendency to take as their topics Korean sociocultural structures and phenomena, or current issues in Korea, and that they frequently employed guided writing formats by providing preset ideas or/and contexts for test-takers to write in a guided way; such tendencies were analyzed to shed a negative influence on test-takers displaying their writing ability and creativity, because those topics and preset ideas or contexts provided do not allow them to express their own opinions or positions freely. It is suggested that TOPIK essay-writing questions should be changed to deal with objective and general topics which enable test-takers to write freely and logically in Korean based on their experience, because TOPIK is not a test to check whether they have enough background knowledge about the Korean society and culture, but a test to assess their Korean proficiency.

• Computers and Concrete
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• 제23권2호
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• pp.97-106
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• 2019

This paper describes the design of a new interlocking masonry system, the production of designed interlocking units and mechanical properties of interlocked masonry assemblages with mortar. In this proposed system, units have horizontal and vertical locks to integrate the units to the wall and have a channel to enable the use of horizontal reinforcements in the wall. Using these units, unfilled, filled or reinforced walls can be constructed with or without mortar. In the production of the interlocking units, it was decided to use foamed concrete. 12 trial productions have been carried out at different mix proportions to obtain the optimum concrete mix. At the end of the mentioned productions, the units were produced with foam concrete which is selected as the most suitable in terms of compressive strength and specific gravity. Then, axial compression, diagonal tension and bed joint shear tests were carried out to determine the mechanical properties of the interlocked masonry assemblages with mortar. Results from the tests showed that interlocks designed to strengthen the system against shear stresses by creating discontinuity throughout the joints have been successful to achieve their aim. Obtained data will enable structural analysis of walls to be constructed with these new units.

• The Journal of Asian Finance, Economics and Business
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• 제8권4호
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• pp.687-697
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• 2021

This study aims to address the prevailing skepticism that conventional leadership models are not effective in the Middle East. With the same logic, selecting leaders is a confusing task in the Middle East due to the haphazardness surrounding this task and the lack of clarity of appropriate selection criteria. This study employs samples of leadership theories and frameworks that were scrutinized to classify specific leadership dimensions. The triangular model stemmed from the previous studies that addressed Leadership in general and the Leadership model for the Middle East. With the use of the literature review methodologies and historical analysis, the leadership model's description will be demonstrated. The results revealed that there are various dimensions of Leadership, especially concerning the Middle East's organizational environment. The findings of this study suggested a new model which assists in clarifying the issue by setting a group of 10 personality traits with eight behavioral skills and social status. Implications of this study enable making Leadership easier in practice. Furthermore, this will enable recognition of Leadership according to specific criteria, which will help make greater equality and empowerment at all levels of the system. This research localizes Leadership and paves the way to automate leaders' selection process with a guarantee of fairness among candidates.

• Archives of Plastic Surgery
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• 제48권1호
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• pp.84-90
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• 2021

Vascularized bone grafts (VBGs) are widely employed to reconstruct upper extremity bone defects. Conventional bone grafting is generally used to treat defects smaller than 5-6 cm, when tissue vascularization is adequate and there is no infection risk. Vascularized fibular grafts (VFGs) are mainly used in the humerus, radius or ulna in cases of persistent non-union where traditional bone grafting has failed or for bone defects larger than 6 cm. Furthermore, VFGs are considered to be the standard treatment for large bone defects located in the radius, ulna and humerus and enable the reconstruction of soft-tissue loss, as VFGs can be harvested as osteocutaneous flaps. VBGs enable one-stage surgical reconstruction and are highly infection-resistant because of their autonomous vascularization. A vascularized medial femoral condyle (VFMC) free flap can be used to treat small defects and non-unions in the upper extremity. Relative contraindications to these procedures are diabetes, immunosuppression, chronic infections, alcohol, tobacco, drug abuse and obesity. The aim of our study was to illustrate the use of VFGs to treat large post-traumatic bone defects and osteomyelitis located in the upper extremity. Moreover, the use of VFMC autografts is presented.

• 한국군사과학기술학회지
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• 제24권2호
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• pp.204-210
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• 2021

In this paper, we studied a method of wirelessly checking up the POD for captive flight tests which is performed during the development of guided weapons systems. The wireless power transfer module, the power distribution device, and the battery pack were designed to wirelessly power the captive flight test POD, and the communication device was designed to enable wireless communication between the POD and the check-up device. The communication device was designed to enable WiFi, IR communication, and laser diode communication, so that various communication methods could be tested. Through the performance test, it was confirmed that power was stably supplied to the captive flight test POD, and the wireless communication performance was verified by measuring the delay time and error rate. As a result, by using our system the POD check-up for the captive flight test was performed wirelessly and the data of the captive equipment could be obtained effectively.

• 신재생에너지
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• 제17권3호
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• pp.16-23
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• 2021

Recently, the Korean government announced a plan to activate renewable energies, with focus on clean energy sources such as solar and wind power as the core and the goal of achieving carbon neutrality by 2050. Unlike other photovoltaic (PV) systems, offshore PV installations are advantageous for large-scale expansion because of the ease of securing sites; they also enable lowering the power generation costs based on construction of large-scale power facilities of megawatt class or higher owing to low noise and landscape damage. However, any power generation should proceed with consideration of the special environmental conditions of the ocean. Above all, when installing large-scale facilities, it is important to reduce fluctuations of the structure and secure stability to actively respond to waves. This study is concerned with the development of a floating body technology that actively responds to waves so as to enable commercialization of offshore solar power. A unit platform for research and development on offshore PV generation was installed in the Saemangeum sea, and the structural fluctuations and stability were analyzed to ensure conformity with the major performance indicators.

• International Journal of Computer Science & Network Security
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• 제23권5호
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• pp.13-20
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• 2023

In connected vehicles, drivers are exposed to attacks when they communicate with unauthenticated peers. This occurs when a vehicle relies on outdated information resulting in interactions with vehicles that have expired or revoked certificates claiming to be legitimate nodes. Vehicles must frequently receive or query an updated revoked certificate list to avoid communicating with suspicious vehicles to protect themselves. In this paper, we propose a scheme that works on a highway divided into clusters and managed by roadside units (RSUs) to ensure authenticity and preserve hidden identities of vehicles. The proposed scheme includes four main components each of which plays a major role. In the top hierarchy, we have the authority that is responsible for issuing long-term certificates and managing and controlling all descending intermediate authorities, which cover specific regions (e.g., RSUs) and provide vehicles with short-term pseudonyms certificates to hide their identity and avoid traceability. Every certificate-related operation is recorded in a blockchain storage to ensure integrity and transparency. To regulate communication among nodes, security managers were introduced to enable authorization and access right during communications. Together, these components provide vehicles with an immediately revoked certificate list through RSUs, which are provided with publish/subscribe brokers that enable a controlled messaging infrastructure. We validate our work in a simulated smart highway environment comprising interconnected RSUs to demonstrate our technique's effectiveness.