• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2006년도 춘계학술대회
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• pp.478-481
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• 2006

Energy is vital to global prosperity, yet dependence on fossil fuels as our primary energy source contributes to global climate change environmental degradation, and health problems. Hydrogen $(H_2)$ offers tremendous potential as a clean renewable energy currency. Hydrogen has the highest gravimetric energy density of any known fuel and is compatible with electrochemical and combustion processes for energy conversion without producing carbon-based emission that contribute to environmental pollution and climate change. Numerous methodologies have been developed for effective hydrogen production. Among them, the biological hydrogen production has gained attention, because hydrogen can be produced by cellular metabolismunder the presence of water and sunlight. The green alga Chlamydomonas reinhardtii is capable of sustained $H_2$ photoproduction when grown under sulfur deprived condition. Under sulfur deprived conditions, PSII and photosynthetic $O_2$ evolution are inactivated, resulting in shift from aerobic to anaerobic condition in the culture. After anaerobiosis, sulfur deprived algal cells induce a reversible hydrogenase and start to evolve $H_2$ gas in the light. According to above principle, we investigated the effect of induction parameters such as cell age, cell density. light intensity, and sulfate concentration under sulfur deprived condition We also developed continuous hydrogen production system by sulfate re-addition under sulfur deprived condition.

• 한국직업건강간호학회지
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• 제28권3호
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• pp.125-137
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• 2019

Purpose: The purpose was to investigate the literature on depression among South Korean nurses in order to identify overall trends regarding depression. Methods: Forty-five papers published between 1998 and 2017 in three Korean databases-RISS4U, DBPIA, and KISS-were analyzed. Results: Depression showed significant positive associations with job stress, burnout, intent to leave, and somatic symptoms such as fatigue and trouble sleeping. Poor work environments such as staff shortage, work overload, and shift work were also positively associated with depression. Higher job satisfaction, resilience, self-efficacy, self-esteem, and social support were negatively correlated with and acted as significant buffers against depression. Conclusion: These results indicate that healthcare policymakers must pay more attention to the management and prevention of nurses' depression. In order to effectively do so, poor work conditions, which involve long working hours, high patient-to-nurse ratios, and extreme workloads, should be improved. Simultaneously, nursing managers should implement initiatives such as counseling and competency improvement programs, and stress management to reduce and prevent depression among nurses and strengthen their positive competency. Also, further research is required to clarify the prevalence of depression in South Korean nurses, with more meta-analyses also required to identify variations in depression rates owing to various factors.

• 한국분말재료학회지
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• 제28권2호
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• pp.150-163
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• 2021

Interest in eco-friendly materials with high efficiencies is increasing significantly as science and technology undergo a paradigm shift toward environment-friendly and sustainable development. MXenes, a class of two-dimensional inorganic compounds, are generally defined as transition metal carbides or nitrides composed of few-atoms-thick layers with functional groups. Recently MXenes, because of their desirable electrical, thermal, and mechanical properties that emerge from conductive layered structures with tunable surface terminations, have garnered significant attention as promising candidates for energy storage applications (e.g., supercapacitors and electrode materials for Li-ion batteries), water purification, and gas sensors. In this review, we introduce MXenes and describe their properties and research trends by classifying them into two main categories: transition metal carbides and nitrides, including Ti-based MXenes, Mo-based MXenes, and Nb-based MXenes.

• 비교문화연구
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• 제36권
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• pp.241-270
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• 2014

The aim of this article is to review the traditional methodologies of teaching translation that concentrate on text-typologies and, as an alternative, to propose an eclectic multi-componential approach that involves a set of interdisciplinary skills with a view to improving the trainee translators' competences and skills. To this end, three approaches, namely a minimalist approach, a pre-transferring adjustment approach and a revision vs. editing approach are proposed to shift the focus of attention from teacher-centred approaches towards student-centred approaches. It has been shown that translator training programmes need to focus on improving the trainee translators' competences and skills, such as training them how to produce and select among the different versions they produce by themselves with justified confidence as quickly as they can (minimalist approach), adjust the original text semantically, syntactically and/or textually in a way that the source text supplely accommodates itself in the linguistic system of the target language (pre-transferring adjustment), and revise and edit others' translations. As the validity of the approach proposed relies partially on instructors' competences and skills in teaching translation, universities, particularly in the Arab world, need to invest in recruiting expert practitioners instead of depending mainly on bilingual teachers to teach translation.

• 스마트미디어저널
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• 제12권2호
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• pp.15-26
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• 2023

전 세계적인 COVID-19 팬데믹으로 인해 업무처리 방식이 원격으로 전환됨에 따라 기업의 외부에서 내부 중요리소스에 접근하는 빈도가 기하급수적으로 증가하였고 기업은 각종 보안 위협에 쉽게 노출되었다. 이러한 접근 보안 문제를 해결하기 위해 ZTA(Zero Trust Architecture) 솔루션이 주목받고 있다. ZTA는 사전에 설정한 정책에 따라 접근에 대한 인증과 허가를 엄격하게 관리하며 외부 유저는 물론 내부 유저도 신뢰하지 않는다는 원칙을 기반으로 동작한다. 본 논문에서는 ZTA의 정의를 포함해 주요 연구 동향을 분석하였고 각 기업별로 상이한 ZTA 솔루션을 정리하였다.

• Journal of Platform Technology
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• 제11권1호
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• pp.3-10
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• 2023

최근 Unmanned Aerial Vehicles (UAVs)은 높은 유동성 및 낮은 하드웨어 비용으로 5G, 6G 무선 통신에서 큰 관심을 받고 있다. 여전히 Blockage와 에너지 문제가 존재하지만 이러한 문제들은 Reconfigurable Intelligent Surface (RIS)를 활용하여 해결할 수 있다. 또한 RIS를 UAV 통신에 이용함으로써 신호를 받지 못하는 사용자에게 신호를 전송하여 Spectral Efficiency를 향상시키며, 에너지 소비를 줄일 수 있다. 현재 대부분의 연구들은 송신 전력과 RIS 위상을 교대로 최적화하여 Power Consumption 최소화 및 데이터 전송 Delay 최소화 등의 목적을 달성하였다. 본 논문에서는 대역폭 최적화를 포함하여 합산 정보 전달율을 최대화하는 알고리즘을 제안한다. 이에 대한 성능평가를 진행하였고, 시뮬레이션을 통해 제안한 알고리즘의 우수성을 보였다.

• 한국항만학회지
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• 제11권2호
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• pp.191-202
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• 1997

As the suitability of berth allocation will ultimately have a significant influence on the performance of a berth, a great deal of attention should be given to berth allocation. Generally, a berth allocation problem has conflicting factors between servers and users. In addition, there is uncertainty in great extent caused by various factors such as departure delay, inclement weather on route, poor handling equipment, a lack of storage space, and other factors contribute to the uncertainty of arrival and berthing time. Thus, it is necessary to establish berth allocation planning which reflects the positions of interested parties and the ambiguity of parameters. For this, a berth allocation problem is formulated by fuzzy 0-1 integer programming introducing the concept of maximum Position Shift(MPS). But, the above approach has limitations in terms of computational time and computer memory when the size of problem is increased. It also has limitations with respect to the integration of other sub-systems such as ship planning system and yard planning system. For solving such problem, this paper focuses particularly on developing an efficient heuristic algorithm as a new technique of getting an effective solution. And also the suggested algorithm is verified through the illustrative examples and empirical appalicaton to BCTOC.

• 한국조경학회지
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• 제38권2호
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• pp.9-24
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• 2010

본 연구는 조경설계 수업 전반에 대한 학생들의 인식을 조사하고, 설계수업 개선을 위한 방향을 도출하고자하였다. 본 연구는 점차로 대학교육이 절대적인 지식을 전달하는 실증주의적 배경으로부터 학생들 스스로가 지식을 구축해가는 구성주의적 교육방법으로 진화해야 한다는 가정을 둔다. 학생들이 설계수업을 어떻게 경험하고, 느끼고, 이해하고, 평가하고 있는지를 이해하는 것은 이러한 구성주의 철학과 관점을 바탕으로 설계수업을 개선하기 위한 첫 번째 단계이다. 본 연구에서는 설계 스튜디오 교육에 대한 이론적 연구로 교육철학의 변화, 스튜디오 수업의 기원과 변화, 건축분야의 설계 교육의 변화, 그리고 조경교육에 있어서 설계교육에 대한 논의를 고찰하였다. 이를 바탕으로 네 개 대학의 학부생을 대상으로 실시한 설문조사의 내용을 분석하였다. 그 결과, 설계수업은 학생들이 조경설계가로서의 진로를 결정하는데 긍정적 혹은 부정적 영향을 행사하는 것으로 나타났다. 절반 정도의 학생들은 설계수업에 대해 불만을 표시하였으며, 상당한 심적 부담감을 느끼는 것으로 나타났다. 특히 설계과정의 초기단계와 개념을 구체화하는 단계에서 가장 많은 스트레스를 받는 것으로 분석되었고, 진로에 대한 유보적인 집단이 설계수업에 대한 심적 부담감이 가장 큰 것으로 나타났다. 학생들은 스스로의 설계능력에 대해 부정적으로 평가하고 있었으며, 성적이 학생들의 설계능력을 잘 반영해준다고 강하게 믿지 않는 것으로 나타나, 보다 투명한 평가체계에 대한 고민이 이어져야함을 시사한다.

• 한국안광학회지
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• 제20권3호
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• pp.355-362
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• 2015

목적: 확산적 흐림의 투과율이 시력과 대비감도에 미치는 영향에 대하여 알아보았다. 방법: 평균연령 $22.83{\pm}0.50$세의 대학생 30명(남 13명, 여 17명)을 대상으로 Optec$^{(R)}$ 6500으로 시력과 대비감도를 측정하였다. 확산적 흐림의 도구로 백내장 시뮬레이터용 확산필름을 사용하였고, 백내장의 진행 정도나 안개의 농도가 반영될 수 있도록 확산적 흐림의 투과율을 변화시키면서 측정하였다. 결과: 시력과 확산적 흐림의 투과율은 비례식 $VA(T)=1.84{\times}10^{-2}T-0.65$으로 맞춤되었다. 대비감도는 모든 공간주파수에서 감소하였는데, 고공간주파수 대역에서의 대비감도가 더 큰 영향을 받아 정상범위를 먼저 벗어났고 대비감도의 정점은 저공간주파수 방향으로 이동하였다. 대비감도함수들의 교차점으로부터 대비감도가 정상범위를 벗어나는 확산적 흐림의 투과율 및 정점공간주파수의 이동을 산출한 결과, 투과율이 약 78.70%이 되면 대비감도의 정점이 6 cpd에서 3 cpd로 이동하는 것으로, 그리고 약 69.71%이 되면 모든 공간주파수에서의 대비감도가 정상범위를 벗어나는 것으로 평가되었다. 결론: 확산적 흐림의 투과율의 감소는 시력의 저하와 더불어 대비감도의 감소, 정상범위의 이탈 및 정점대비감도 이동 등을 유발시켜 시각적 불편함을 일으킨다는 점에서 백내장이나 안개 운전 시에는 더 많은 주의가 요구된다.

• 한국국방경영분석학회지
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• 제2권1호
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• pp.127-143
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• 1976

The purpose of this thesis is to study the optimal arrangement of aircraft instrument panels through the human factors approach. Human factors engineering is the process of effectively fitting the human component to the machine component in any man-machine system. The human factors. are especially important to an aircraft pilot who must constantly shift his attention between the instrument panel within the cockpit and the surrounding area of the aircraft. The preliminary part of this study is to find the general patterns of the Korean pilot's eye movements during their various flying maneuvers, and which instruments require the most attention while in flight. It is assumed that all pilots have a general pattern of eye movement when observing the aircraft instrument panel and that an optimum arrangement would be to minimize the eye travel distance between instruments. In this thesis the arrangements of instruments is taken to be the independent variable and the eye travel distance between instruments the dependent variable. la order to compile the information necessary for this study, sixty Korean Air Force pilots were interviewed and requested to complete information forms. These information forms listed various flying maneuvers and listed each instrument used on the instrument panel. The compilation of the information on these completed forms listed the instruments most frequently used by the pilots. The second part of this study was to determine the optimum instrument arrangement. It was necessary to study the various number of possible arrangements of instruments depending upon the number of instruments involved. Therefore, these instruments are grouped by two major functions, The flight instruments were subdivided into three groups, and the engineering instruments were subdivided into six groups. With this subdivision we arrive at the possible number of arrangements of 4,320. Through the simulation method, total eye travel distance for each of these 4,320 arrangements is calculated and the arrangement which appears to be of optimum distance between the most frequently used aircraft instruments is determined. The results of this study indicate that the optimum distance between instruments would be 33,028cm and that the corresponding distance of the instrument panel now being used is 34,288cm. Therefore, an increased efficiency of $3.8\%$ would be realized if the existing aircraft instrument panel were re-arranged according to layout proposed in this thesis.