• 한국정밀공학회지
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• 제21권9호
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• pp.77-84
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• 2004

The attachment of mobile vehicle is necessary for the automated operation on the inclined or vertical walls of steel structures. Since the vehicle requires attaching devices additionally, its overall efficiency can be reduced by the devices. Therefore, external shapes of mobile vehicles have to be researched to give the effective movement on the vertical face. For the design of mobile vehicle, the guideline has been derived from the modeling of wall-climbing, so that the vehicle should have a specific external shape for vertical movement due to the gravitational force. Hence, some adequate arrangement of attaching device to the mobile vehicle has been presented for the effective movement. In the experiments with four permanent magnetic wheels, a plausible result was achieved as a vertical attaching force of 185.2(N), a friction force of 153.8(N) and a curvature radius of 1.4m. The mobile vehicle should be modified according to the proposed design guideline, and then it could be applied to a specific operation as an appropriate external shape. Also, Further research is recommended on an optimal posture and a moving method in a specific application, as the attaching force of the vehicle can be affected by its posture.

• 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
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• 제25권1호
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• pp.51-60
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• 2019

Purpose: This study aims to analyze design guidelines for hospice facilities in the US, UK, and Canada focused on design considerations and space requirements, and utilizes them as baseline data for establishing standards for Korean hospice facilities. Methods: Comparative review was carried out to investigate hospice care models, design consideration, and room sizes and requirements for design guideline of hospice facilities in United States, UK and Canada identified on electronic database and review articles, and to examine major characteristics and tendencies of hospice facilities. Results: The hospice care models characteristics in design guidelines is generally largely divided into hospital-based hospice facility, Nursing home-based hospice facility, and daycare hospice. The design considerations in hospice facilities focused on medical efficiency, flexibility, barrier-free environment, person-centered care, and stability. There is also a need for single resident room, rooms for the patient's family, and isolation room for infection control. Implications: it is recommended to establish standards for the installation and operation of required and recommended rooms and considerations when establishing the standards of hospice facilities in Korea. This Study is limited to a simple comparative analysis of the framework of guideline.

• Journal of Power Electronics
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• 제11권2호
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• pp.194-201
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• 2011

The air flow supplied to a fuel cell system is one of the most significant factors in determining fuel efficiency. The conventional method of controlling the air flow is to fix the oxygen supply at an estimated constant rate for optimal efficiency. However, the actual optimal point can deviated from the pre-set value due to temperature, load conditions and so on. In this paper, the maximum efficiency point tracking (MEPT) algorithm is proposed for finding the optimal air supply rate in real time to maximize the net-power generation of fuel cell systems. The fixed step MEPT algorithm has slow dynamics, thus it affects the overall efficiency. As a result, the variable step MEPT algorithm is proposed to compensate for this problem instead of a fixed one. The complete small signal model of a PEM Fuel cell system is developed to perform a stability analysis and to present a design guideline. For a design example, a 1kW PEM fuel cell system with a DSP 56F807 (Motorola Inc) was built and tested using the proposed MEPT algorithm. This control algorithm is very effective for a soft current change load like a grid connected system or a hybrid electric vehicle system with a secondary energy source.

• International Journal of Naval Architecture and Ocean Engineering
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• 제12권1호
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• pp.440-454
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• 2020

To prevent pollution from ships, the Energy Efficiency Design Index (EEDI) is a mandatory guideline for all new ships. The Ship Energy Efficiency Management Plan (SEEMP) has also been applied by MARPOL to all existing ships. SEEMP provides the Energy Efficiency Operational Indicator (EEOI) for monitoring the operational efficiency of a ship. By monitoring the EEOI, the shipowner or operator can establish strategic plans, such as routing, hull cleaning, decommissioning, new building, etc. The key parameter in calculating EEOI is Fuel Oil Consumption (FOC). It can be measured on board while a ship is operating. This means that only the shipowner or operator can calculate the EEOI of their own ships. If the EEOI can be calculated without the actual FOC, however, then the other stakeholders, such as the shipbuilding company and Class, or others who don't have the measured FOC, can check how efficiently their ships are operating compared to other ships. In this study, we propose a method to estimate the EEOI without requiring the actual FOC. The Automatic Identification System (AIS) data, ship static data, and environment data that can be publicly obtained are used to calculate the EEOI. Since the public data are of large capacity, big data technologies, specifically Hadoop and Spark, are used. We verify the proposed method using actual data, and the result shows that the proposed method can estimate EEOI from public data without actual FOC.

• 한국통신학회논문지
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• 제29권8C호
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• pp.1086-1103
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• 2004

Most research efforts on the OCDMA technology assume single-bit-per-symbol transmission techniques such as on-off keying. However, achieving high spectral efficiency with such transmission techniques is likely to be a challenging task due to the "unipolar" nature of optical signals. In this paper, an M-ary transmission technique using more than two equally-weighted codes is proposed for OCDMA local area networks, and ie BER performance and spectral efficiency are analyzed. Poison frame arrival and randomly generated codes are assumed for the BER analysis, and the probability of incorrect symbol detection is analytically derived. From the approximation, it is found that there exists an optimal code weight that minimizes the BER, and its physical interpretation is drawn in an intuitive and simple statement. Under the assumption of this optimized code weight and sufficiently large code dimension, it is also shown that the spectral efficiency of OCDMA networks can be significantly improved by increasing the number (M) of symbols used. Since the cost of OCDMA transceivers is expected to increase with the code dimension, we finally provide a guideline to determine the optimal number of symbols for a given code dimension and traffic load.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 하계학술대회 논문집
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• pp.438-438
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• 2009

We have investigated the effect of forming gas annealing for Upgraded Metallurgical Grade (UMG)-silicon solar cell in order to obtain low-cost high-efficiency cell using post deposition anneal at a relatively low temperature. We have observed that high concentration hydrogenation effectively passivated the defects and improved the minority carrier lifetime, series resistance and conversion efficiency. It can be attributed to significantly improved hydrogen-passivation in high concentration hydrogen process. This improvement can be explained by the enhanced passivation of silicon solar cell with antireflection layer due to hydrogen re-incorporation. The results of this experiment represent a promising guideline for improving the high-efficiency solar cells by introducing an easy and low cost process of post hydrogenation in optimized condition.

• 한국정보시스템학회지:정보시스템연구
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• 제26권2호
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• pp.143-164
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• 2017

Purpose The purpose of this study is to investigate to investigate the effects of cloud system on the efficiency improvement and cost-saving of production processes. It also tries to provide small- and medium-sized companies and IT practitioners with a practical guideline for a successful implementation of could systems. Design/methodology/approach This study was conducted by observing and analyzing a case of implementing a cloud system at a small-sized company having multiple job sites in terms of the improvement in data-sharing efficiency and cost-saving of production processes. Findings This study found that cloud system was an effective way of sharing data between and among production processes of geographically scattered job sites and thus, helped the company to remedy problems of work schedule and load-balance along sequential production processes. Cloud system also allowed the company to reduce the number of visits made by 3-inspectors to four job sites by 75% and the personnel cost related to inspectors' site visit.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2012년도 춘계 학술논문 발표대회
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• pp.47-48
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• 2012

In this study, the CO₂ emission and economic efficiency of high-rise apartment houses were evaluated, and were analyzed as a way to establish database on the evaluation of environment-friendliness of high-rise buildings. To that end, standard of buildings to be evaluated were proposed through analysis of the designing guideline for high-rise apartment houses proposed by Seoul city, and CO₂ emission of the subject buildings were evaluated based on the characteristics of materials admitted into each building and the amounts of energy consumed during lifecycle period. In addition, the initial costs in construction stage and annual costs in operation stage were set as analysis parameters, and along with calculation of direct cost by the consumption of construction materials and energy, the costs of CO₂ emission were evaluated and analyzed. As a result, the CO₂ emission and economic efficiencies of high-rise apartment houses by construction stage and operation stage could be analyzed quantitatively.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2014년도 추계학술대회
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• pp.122-124
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• 2014

최근 모바일게임 시장은 스마트폰의 발전으로 인하여 급속하게 성장하였고, 지금도 빠르게 성장하고 있다. 또한 모바일 웹보드 방식의 게임들도 지속적으로 개발되고 있다. 그러나 사용자들의 사용성에는 여러 의문점들이 발생하고 있다. 이는 게임을 플레이하는 사람들이 사용성에 관한 측면에서 만족하지 못하였기 때문이다. 본 연구에서는 스마트 폰 기반의 웹 보드 게임에서 사용성 요소 중 효율성과 정확성을 기반으로 연구를 진행하여 이에 대한 특징 및 문제점을 분석하는 것을 목적으로 한다. 연구 방법으로는 전통적인 사용성 연구에 대한 문헌을 중심으로 효율성 및 정확성에 관한 연구를 실시하고 스마트폰 기반의 웹 보드 게임에 적합한 사용성 요소를 도출하였다. 이 연구는 향후 스마트폰기반 보드 게임에서의 사용성에 관한 가이드라인을 제시할 것으로 기대된다.

• 산경연구논집
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• 제15권8호
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• pp.21-27
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• 2024

Purpose: There is a significant opportunity for ESG management to act as a useful guideline for social welfare organizational structures when dealing with sustainability and ethical leadership. The ESG guidelines should allow these companies to improve their business efficacy. This paper aims to explore the specific impacts of ESG management on social welfare. Research design, data and methodology: The systematic review approach ensures that quality work is undertaken in tackling the existing gaps in the literature on ESG management in social welfare organizations. The outcomes of this review will give a useful 'real-life' picture of the consequences of ESG practices and suggestions that can increase the efficiency and sustainability of social welfare organizations. Results: The principal favorable consequences are discussed in this chapter regarding the social welfare organization due to the implementation of ESG management. Subsequently, each effect is posted under different sub-titles and evidence from previously conducted research studies. Conclusions: ESG management is vital for social welfare organizations since it increases their efficiency in operations, public image, and opportunities to receive funds, and it helps improve relations with stakeholders. More so, these organizations can embrace the ESG practices and as a result bring more efficiency to the general welfare of the society.