• Journal of Electrochemical Science and Technology
• /
• 제11권1호
• /
• pp.26-32
• /
• 2020

In this study, the side reactions that greatly affect the coulombic efficiency of a zinc-air secondary battery are quantitatively analyzed on the basis of the charging-discharging characteristics, open circuit self-discharge characteristics, and a series of calculations. In particular, the charge amounts consumed by water electrolysis and self-discharge during charging process are separately determined so that the charging efficiency (the amount of charge used in actual charging with respect to the applied charge amount) can be estimated, which would enable systematic understanding of the cause of coulombic efficiency degradation. Using two cells with different charging overvoltages, the validity of the proposed method can be assessed.

• Nuclear Engineering and Technology
• /
• 제45권2호
• /
• pp.203-210
• /
• 2013

The objective of this conducted research is to study the iodine removal efficiency in a self-priming venturi scrubber for submerged and non-submerged operating conditions experimentally and theoretically. The alkaline solution is used as an absorbent, which is prepared by dissolving sodium hydroxide (NaOH) and sodium thiosulphate ($Na2S_2O_3$) in water to remove the gaseous iodine ($I_2$) from the gas. Iodine removal efficiency is examined at various gas flow rates and inlet concentrations of iodine for submerged and non-submerged operating conditions. In the non-submerged venturi scrubber, only the droplets take part in iodine removal efficiency. However, in a submerged venturi scrubber condition, the iodine gas is absorbed from gas to droplets inside the venturi scrubber and from bubbles to surrounding liquid at the outlet of a venturi scrubber. Experimentally, it is observed that the iodine removal efficiency is greater in the submerged venturi scrubber as compare to a non-submerged venturi scrubber condition. The highest iodine removal efficiency of $0.99{\pm}0.001$ has been achieved in a submerged self-priming venturi scrubber condition. A mathematical correlation is used to predict the theoretical iodine removal efficiency in submerged and non-submerged conditions, and it is compared against the experimental results. The Wilkinson et al. correlation is used to predict the bubble diameter theoretically whereas the Nukiyama and Tanasawa correlation is used for droplet diameter. The mass transfer coefficient for the gas phase is calculated from the Steinberger and Treybal correlation. The calculated results for a submerged venturi scrubber agree well with experimental results but underpredicts in the case of the non-submerged venturi scrubber.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2008년도 심포지엄 논문집 정보 및 제어부문
• /
• pp.240-241
• /
• 2008

We are presenting the efficient and robust simplified module based self-collision detection of humanoid robot simulator. For safe and reliable operations of humanoid robot, the self-collision detection is essential and extremely important. The main methods of self-collision detection are inverse X-Y-Z fixed angles and module distance filtering (MDF). According to experiments on the humanoid robot simulator with the self-collision detection, we could have a confidence about the efficiency of the self-collision.

• 한국산학기술학회논문지
• /
• 제14권1호
• /
• pp.157-168
• /
• 2013

본 연구의 목적은 취업준비 과정에서 장애인이 경험하게 되는 진로장벽을 파악하고, 이러한 진로장벽이 역기능적 진로사고에 미치는 영향을 분석하는 것이다. 이를 위해 직업훈련중인 장애인 180명을 조사한 결과 첫째, 장애인이 지각하는 진로장벽은 직업정보의 부족, 낮은 사회적지지, 자기명확성 부족, 낮은 자기효능감, 중요한 타인과의 갈등 순으로 나타났다. 둘째, 장애인의 연령변인은 자기명확성 부족과 직업정보 부족에서 유의한 차이를 보였으며, 학력 특성에 따라 직업정보 부족에 차이가 나타났다. 또한 장애 유형 중에서는 정신장애가 사회적 지지에 높은 유의미성이 검증되었으나, 성별 차이와, 취업 경험은 모두 차이를 보이지 않았다. 셋째, 역기능적 구직의사결정 혼란에 가장 영향을 미치는 변인은 자기명확성 부족, 중요한 타인과의 갈등 그리고 낮은 자기효능감이었으며, 장애인의 수행불안에 가장 영향을 미치는 진로장벽은 낮은 자기효능감과 중요한 타인과의 갈등으로 나타났다.

• 한국시뮬레이션학회논문지
• /
• 제24권3호
• /
• pp.97-105
• /
• 2015

본 논문은 시뮬레이션을 기반으로 자체 구동 롤러 컨베이어 물류시스템의 전력 효율을 분석하는 연구이다. 물류 시스템의 전력 효율 향상은 온실 가스 배출과 물류 비용을 감소시키는 이점을 가져온다. 자체 구동 롤러 컨베이어는 제품이 접근할 때에만 구동이 된다. 따라서 자체 구동 롤러 컨베이어 기반 시스템은 연속 구동 롤러 컨베이어 시스템에 비해 더 적은 전력을 소비한다. 본 논문에서는 DEVS(이산 사건 기반 시스템) 기반의 시뮬레이션 시스템을 설계하고 자체 구동 롤러와 연속 구동 롤러컨베이어 모델을 구축하였다. 설계된 시뮬레이션시스템과 컨베이어 모델의 검증과 확인을 위해 우리는 실험 환경에 대응하는 물류 모델을 모델링하고 모델과 실제 시스템간의 비교를 하였다. 본 연구의 주된 목적은 시뮬레이션 방법을 사용하여 자체구동 롤러 컨베이어 기반 물류 시스템의 전력 소비의 이점을 설명하는 것이다.

• International Journal of Computer Science & Network Security
• /
• 제21권6호
• /
• pp.23-28
• /
• 2021

The article discusses the features of adaptation of the parameters of the physical layer of data transmission in self-organizing networks based on unmanned aerial vehicles operating in the conditions of "smart cities". The concept of cities of this type is defined, the historical path of formation, the current state and prospects for further development in the aspect of transition to "smart cities" of the third generation are shown. Cities of this type are aimed at providing more comfortable and safe living conditions for citizens and autonomous automated work of all components of the urban economy. The perspective of the development of urban mobile automated technical means of infocommunications is shown, one of the leading directions of which is the creation and active use of wireless self-organizing networks based on unmanned aerial vehicles. The advantages of using small-sized unmanned aerial vehicles for organizing networks of this type are considered, as well as the range of tasks to be solved in the conditions of modern "smart cities". It is shown that for the transition to self-organizing networks in the conditions of "smart cities" of the third generation, it is necessary to ensure the adaptation of various levels of OSI network models to dynamically changing operating conditions, which is especially important for the physical layer. To maintain an acceptable level of the value of the bit error probability when transmitting command and telemetry data, it is proposed to adaptively change the coding rate depending on the signal-to-noise ratio at the receiver input (or on the number of channel decoder errors), and when transmitting payload data, it is also proposed to adaptively change the coding rate together with the choice of modulation methods that differ in energy and spectral efficiency. As options for the practical implementation of these solutions, it is proposed to use an approach based on the principles of neuro-fuzzy control, for which examples of determining the boundaries of theoretically achievable efficiency are given.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2003년도 춘계전력전자학술대회 논문집(2)
• /
• pp.677-680
• /
• 2003

The control of the SRM(Switched Reluctance Motor) is usually based on the non-linear inductance profiles with positions. So determination of optimal switching angle is very different. we present self-tuning control of SRM for maximum torque and efficiency with phase current and shaft position sensor During the sample time, micro-controller checks the number of pre-checked pulse. After micro-controller calculates between two data, it move forward or backward turn-off angle. When the turn-off angle is fixed optimal turn-off angle, turn-on angle moves forward or backward by a step using self-tuning control method. And then, optimal turn-off angle is searched once again. As such a repeating process, turn-on/off angle is moves automatically to obtain the maximum torque and efficiency. The experimental results are presented to validate the self-tuning algorithm.

• 한국가족관계학회지
• /
• 제23권3호
• /
• pp.77-104
• /
• 2018

Objectives: This study aimed to examine the general tendencies of women's divorce intention and to analyze the related variables that affect women's divorce intention. It would help explore the conditions for prevention or intervention of divorce. Methods: For this purpose, the structured survey was conducted by 521 married women aged between 20 and 70 living in Jeollanam-do and Gwangju. The data was analysed by SPSS 21.0 program. Results: First, the average score of divorce intention was 2.04, which was lower than the middle. The average score of self-differentiation, marital communication efficiency, reasonable coping, and social support were a bit higher than the median score. Second, the differences in the divorce intention according to the academic background and household income were statistically significant. Third, marital communication efficiency had the biggest effect on divorce intention and it was followed by avoidance-oriented behavior, reasonable coping, support from the local community, self-differentiation, and household income. Conclusion: It is very important to understand the various factors related to divorce intention especially in individual, marital, social aspects. In addition, it is actually required to develop the couple programs about coping strategies, effective couple communication and problem-solving methods. It also have to imply the requirements considering psychological, social aspects such as self-differentiation and social support.

• 복식문화연구
• /
• 제24권2호
• /
• pp.198-217
• /
• 2016

This study analyzed the effects of organizational culture on psychological empowerment and organization efficiency, and the effects of psychological empowerment on organization efficiency in fashion companies. In addition, this study analyzed the differences between organizational culture, psychological empowerment and organization efficiency across demographic characteristics. The survey was conducted among employees of fashion companies, and 320 responses were used in the data analysis. As a result, the group culture and innovative culture in fashion companies positively influenced the competence and meaning of psychological empowerment. An innovative culture and rational culture positively influenced the self-determination, and the group culture and rational culture positively influenced the impact of psychological empowerment. The group culture, innovative culture, and rational culture of fashion companies positively influenced job satisfaction, and the group culture, innovative culture, and hierarchical culture positively influenced job commitment. The group culture and innovative culture negatively influenced the turnover intention, but the hierarchical culture positively influenced the turnover intention. In addition, the psychological empowerment (competence, self-determination, impact, and meaning) positively influenced job satisfaction, and the competence, self-determination, and impact positively influenced job commitment. Competence negatively influenced the turnover intention, but the impact positively influenced the turnover intention. There was a difference in the group culture and turnover intention by ages, as well as a difference in the hierarchical culture and self-determination by work departments. The results of this study will be helpful for the establishment of the management and business strategies in fashion companies.

• Journal of Radiation Protection and Research
• /
• 제26권2호
• /
• pp.51-58
• /
• 2001

환경방사능과 같은 저준위 방사능 측정에서는 원통형과 Marinelli형 측정용기가 가장 일반적으로 사용된다. 효율교정용 표준선원과 측정시료의 높이 또는 매질의 밀도가 다르면 자체흡수 효과의 차이로 인한 보정이 필요하다. 본 연구에서는 Monte Carlo 방법을 이용하여 HPGe 검출기의 전에너지 피크 효율을 계산하여 측정치와 비교하였다. 원통형 용기에 대해서는 높이에 대한 효율변화 정도를 계산하였고, 원통형 및 Marinelli 측정용기에 대해서는 밀도변화에 따른 효율을 계산하였다. 밀도에 따른 효율의 감소 정도는 1000keV 이하의 에너지 영역에 대해 자체흡수 효과의 보정치 필요하다는 것을 알았다. 또한 계산의 타당성을 검증하기 위하여 NIST SRM 4353 표준물질을 이용하여 계산값과 인증값을 상호비교한 결과 오차범위 이내로 잘 맞는 다는 것을 확인하였다.