• 제목/요약/키워드: Sharing current control

검색결과 189건 처리시간 0.029초

A Buck-Boost Type Charger with a Switched Capacitor Circuit

  • Wu, Jinn-Chang;Jou, Hurng-Liahng;Tsai, Jie-Hao
    • Journal of Power Electronics
    • /
    • 제15권1호
    • /
    • pp.31-38
    • /
    • 2015
  • In this paper, a buck-boost type battery charger is developed for charging battery set with a lower voltage. This battery charger is configured by a rectifier circuit, an integrated boost/buck power converter and a switched capacitors circuit. A boost power converter and a buck power converter sharing a common power electronic switch are integrated to form the integrated boost/buck power converter. By controlling the common power electronic switch, the battery charger performs a hybrid constant-current/constant-voltage charging method and gets a high input power factor. Accordingly, both the power circuit and the control circuit of the developed battery charger are simplified. The switched capacitors circuit is applied to be the output of the boost converter and the input of the buck converter. The switched capacitors circuit can change its voltage according to the utility voltage so as to reduce the step-up voltage gain of the boost converter when the utility voltage is small. Hence, the power efficiency of a buck-boost type battery charger can be improved. Moreover, the step-down voltage gain of the buck power converter is reduced to increase the controllable range of the duty ratio for the common power electronic switch. A prototype is developed and tested to verify the performance of the proposed battery charger.

Developing an IFC-based database for construction quality evaluation

  • Xu, Zhao;Li, Bingjing;Li, Qiming
    • 국제학술발표논문집
    • /
    • The 7th International Conference on Construction Engineering and Project Management Summit Forum on Sustainable Construction and Management
    • /
    • pp.301-312
    • /
    • 2017
  • Quality evaluation and control represent increasingly important concerns for construction quality management. There is an evident need for a standard data model to be used as the basis for computer-aided quality management. This study focuses on how to realize evaluation of construction quality based on BIM and database technology. In this paper, the reinforced concrete main structure is taken as an example, and the BP neural network evaluation model is established by inquiring current construction quality acceptance specification and evaluation standard. Furthermore, IFC standard is extended to integrate quality evaluation information and realize the mapping of evaluation information in BIM model, contributing to the visualization and transfer sharing of evaluation information. Furthermore, the conceptual entity model is designed to build quality evaluation database, and this paper select MySQL workbench system to achieve the establishment of the database. This study is organized to realize the requirement of visualization and data integration on construction quality evaluation which makes it more effective, convenient, intuitive, easy to find quality problems and provide more comprehensive and reliable data for the quality management of construction enterprises and official construction administratiors.

  • PDF

Holographic Recording Versus Holographic Lithography

  • Seungwoo Lee
    • Current Optics and Photonics
    • /
    • 제7권6호
    • /
    • pp.638-654
    • /
    • 2023
  • Holography is generally known as a technology that records and reconstructs 3D images by simultaneously capturing the intensity and phase information of light. Two or more interfering beams and illumination of this interference pattern onto a photosensitive recording medium allow us to control both the intensity and phase of light. Holography has found widespread applications not only in 3D imaging but also in manufacturing. In fact, it has been commonly used in semiconductor manufacturing, where interference light patterns are applied to photolithography, effectively reducing the half-pitch and period of line patterns, and enhancing the resolution of lithography. Moreover, holography can be used for the manufacturing of 3D regular structures (3D photonic crystals), not just surface patterns such as 1D or 2D gratings, and this can be broadly divided into (i) holographic recording and (ii) holographic lithography. In this review, we conceptually contrast two seemingly similar but fundamentally different manufacturing methods: holographic recording and holographic lithography. We comprehensively describe the differences in the manufacturing processes and the resulting structural features, as well as elucidate the distinctions in the diffractive optical properties that can be derived from them. Lastly, we aim to summarize the unique perspectives through which each method can appear distinct, with the intention of sharing information about this field with both experts and non-experts alike.

재난안전정보 관리를 위한 어휘자원 현황분석 및 활용방안 (A Study on the Utilization Plan of Lexical Resources for Disaster and Safety Information Management Based on Current Status Analysis)

  • 정힘찬;김태영;김용;오효정
    • 정보관리학회지
    • /
    • 제34권2호
    • /
    • pp.137-158
    • /
    • 2017
  • 재난은 국민의 생명 신체 재산에 직접적인 영향을 미치는 사건으로, 재난 발생 시 신속하고 효과적인 대응을 위해서는 관련 정보들을 효율적으로 공유, 활용하는 협조 과정이 무엇보다도 중요하다. 현재 재난안전 유관기관별로 다양한 재난안전정보가 생산 및 관리되고 있지만, 각 기관별로 개별적인 용어와 의미를 정의하여 활용하고 있다. 이는 재난안전정보를 검색하고 접근하려는 실무자 입장에서 큰 걸림돌이며, 기관별 정보 활용도를 저해시키는 요인 중에 하나이다. 이러한 문제점을 해결하기 위해 재난안전정보의 통합적 관리를 위한 어휘자원의 표준화 작업의 선행 연구로, 본 연구에서는 재난안전 유관기관에서 관리하고 있는 어휘자원의 현황분석을 수행하였다. 또한 수집된 어휘자원을 대상으로 정보제공자 및 이용자 관점에서의 활용도 분석을 통해 어휘 그룹별 특성을 파악하고 이에 기반해 재난안전정보 관리를 위한 활용방안을 제안하였다.

변형된 승강압 컨버터의 병렬구동에 의한 태양광발전 (Photovoltaic Generation by Parallel Driving of Modified Buck-boost Converter)

  • 이희창;박성준;박수식;문채주;이만형;김종달
    • 전력전자학회논문지
    • /
    • 제9권5호
    • /
    • pp.457-466
    • /
    • 2004
  • 본 논문에서는 태양광 컨버터로서 변형된 벅-부스트 컨버터를 제안하고 분석하며, 출력을 증가시키고 출력전압의 리플을 저감하기 위한 새로운 병렬 구동 기법을 제안한다. 변형된 컨버터의 입ㆍ출력 관계는 기존의 승압형 컨버터인 부스트 컨버터와 동일하지만, 출력단자의 구성을 변형시켜 출력 콘덴서의 동작전압과 커패시턴스 용량을 저감시킬 수 있는 장점을 가진다. 또한 변형된 컨버터와 전류 제어 기법을 이용하는 제안된 병렬구동 기법은 기존병렬 구동 방식의 전류 분배에 대한 불평등 문제를 해결할 수 있으며, 부가적인 스위칭 손실의 증가 없이 등가 스위칭 주파수를 증가 시킬 수 있어 출력전압 리플 저감에 효과적이다. 제안된 병렬 구동 기법의 타당성을 컴퓨터 시뮬레이션과 실험을 통하여 입증한다.

Recommendation Model for Battlefield Analysis based on Siamese Network

  • Geewon, Suh;Yukyung, Shin;Soyeon, Jin;Woosin, Lee;Jongchul, Ahn;Changho, Suh
    • 한국컴퓨터정보학회논문지
    • /
    • 제28권1호
    • /
    • pp.1-8
    • /
    • 2023
  • 점점 더 복잡해지고 다양해지는 무기체계와 급격하게 변화하는 전장정보에 따라서, 인공지능을 사용한 전장 상황 분석 연구의 필요성이 대두되고 있다. 본 논문에서는 전장 상황을 분석하여 현재 상황에 적합한 가설을 추천해주는 분석결과 추천 학습모델의 학습 및 설계 방안을 제안한다. 학습 모델은 두 가설을 비교하여 결정되는 선호 여부를 레이블 데이터로 활용하여, 어떠한 가설이 현재 전장상황을 잘 분석하고 있는지 학습한다. 또한 후처리 랭킹 알고리즘을 통하여 각각의 가설에 대한 종합점수를 부여하고, 점수가 높은 상위 가설들을 지휘관에게 추천할 수 있음을 확인한다.

Development of web-based collaborative framework for the simulation of embedded systems

  • Yang, Woong;Lee, Soo-Hong;Jin, Yong Zhu;Hwang, Hyun-Tae
    • Journal of Computational Design and Engineering
    • /
    • 제3권4호
    • /
    • pp.363-369
    • /
    • 2016
  • Cyber Physical System (CPS) and Internet of Things (IoT) are hot objects of interest as an extension of the embedded system. These interactive products and systems contain Mobile Devices which are most popular and used most frequently. Also these have been widely used from the control of the Nuclear Power Control System (NPCS) to IoT Home Service. Information & Communication Technology (ICT) topics of trend fused-complex current Information Technology (IT) and Communication Technology (CT) are closely linked to real space and virtual space. This immediately means the arrival of the ultra-connected society. It refers to a society in which various objects surrounding the human innovation and change in the social sector are expected through the connection between the data which are to be generated. In addition, studies of Tool-kit for the design of such systems are also actively pursued. However, only increased cooperation and information sharing between the physical object consists of a variety of machinery and equipment. We have taken into consideration a number of design variables of the high barriers to entry about the product. In this study, It has been developed a Web-based collaboration framework which can be a flexible connection between macroscopically virtual environment and the physical environment. This framework is able to verifiy and manage physical environments. Also it can resolve the bottlenecks encountered during the base expansion and development process of IoT (Internet of Things) environment.

폐암 클리닉을 위한 공유 전자의무기록 (A Shared Electronic Medical Record for Lung Cancer Clinic)

  • 김규식;박은선;김승석;김형우;김영철;범희승;안성자;나국주;김윤현;김유일;임성철;문재동
    • Tuberculosis and Respiratory Diseases
    • /
    • 제59권5호
    • /
    • pp.480-486
    • /
    • 2005
  • Since the year 2000, lung cancer has become the leading cause of cancer death in South Korea as in many other parts of the world. The current multidisciplinary approach for lung cancer includes a wide range of modalities, not only surgery, radiotherapy, medical drug therapy but also pain control, as well as social and psychological support. Therefore, thoracic surgeons, radiologists, nuclear medicine specialists, anesthetists, psychologist, nurses and social workers as well as medical doctors care for lung cancer patients. Sharing a common treatment protocol and optimal communication are vital aspects of shared care both from a medical and cost-effectiveness point of view. We developed a shared electronic medical record (SEMR) for treating patients with lung cancer in a university hospital to facilitate the sharing protocols and communications between doctors involved in a lung cancer clinic. A SEMR system was developed within a order communication system(OCS) for a lung cancer clinic. The records of radiological, laboratory and pathological studies as well as the records of surgery, chemotherapy, and radiotherapy were stored and presented to all doctors who treat the same patient. Every doctor was allowed to change his/her own records. They could review other doctor s records but could not alter them. With the SEMR, it was expected that the time to complete the medical records for one patient could be reduced because it was easy to review all the data from the other doctors who share the same patient. In addition, the confidence of the doctors who share a common treatment protocol would be higher. Therefore, a shared electronic medical record is expected to improve the quality of patient care.

손 끝 온도변화가 젊은 성인의 다중 손가락 동작에 미치는 효과 (Effect of Fingertip Temperature on Multi-finger Actions in Young Adults)

  • Shin, Narae;Xu, Dayuan;Song, Jun Kyung;Park, Jaebum
    • 한국운동역학회지
    • /
    • 제29권3호
    • /
    • pp.157-166
    • /
    • 2019
  • Objective: This study examined the effects of stimulating fingertip temperature on the patterns of force sharing and stability properties during multi-finger force production tasks. Method: 9 adult subjects (male: 3, female: 6, age: $26.11{\pm}4.01yrs$, height: $169.22{\pm}5.97cm$, weight: $61.44{\pm}11.27kg$) participated in this study. The experiment consisted of three blocks: 1) maximal voluntary contraction (MVC) task, 2) single-finger ramp task to quantify enslaving (i.e., unintended force production by non-task fingers), and 3) 12 trials of multi-finger steady-state force production task at 20% MVC. There were three temperature conditions including body-temperature (i.e., control condition), $40^{\circ}C$, and $43^{\circ}C$, and the stimulation was given to the index finger only for all experimental conditions. Results: There were no significant differences in the MVC forces, enslaving, and the accuracy of performance during the steady-state task between the conditions. However, the share of stimulated index finger force increased with the index fingertip temperature, while the share of middle finger force decreased. Also, the coefficient of variation of both index and middle finger forces over repetitive trials increased with the index fingertip temperature. Under the framework of the uncontrolled manifold (UCM) hypothesis used to quantify indices of multi-finger synergies (i.e., stability property) stabilizing total force during the steady-state task, the two variance components within the UCM analysis increased together with the fingertip temperature, while no changes in the synergy indices between the conditions. Conclusion: The current results showed that fingertip temperature stimulation only to index finger does not affect to muscle force production capability of multi-finger, independence of individual fingers, and force production accuracy by the involvement of all four fingers. The effect of fingertip temperature on the sharing pattern and force variation may be due to diffuse reflex effects of the induced afferent activity on alpha-motoneuronal pools. However, the unchanged stability properties may be the reflection of the active error compensation strategies by non-stimulated finger actions.

공급사슬 관리 구축전략에 관한 연구: LG전자 사례 중심으로 (A study of SCM strategic plan: Focusing on the case of LG electronics)

  • 이기원;이상윤
    • 유통과학연구
    • /
    • 제9권3호
    • /
    • pp.83-94
    • /
    • 2011
  • 국내에서는 일부 대기업을 제외하고는 공급사슬 관리(SCM) 체제 구축에 매우 소극적이며, 중소기업들은 SCM관리의 개념조차 인식하고 있는 경우가 대 다수이다. 이는 공급망 비효율적 관리로 인한 국내 제조업체, 협력업체, 유통업체 및 물류업체들 재고관리 비용, 수요관리 비용 등 비 효율화를 초래하고 있으며, 나아가 국내 기업의 경쟁력 저하에도 큰 영향력을 미치고 있다. 그 이유는 공급사슬 관리(SCM) 태생적인 특징인 공급사슬 관리(SCM) 전체에 대한 정보 공유 및 프로세스 혁신과, 공급사슬 관리(SCM)가 갖는 광범위함 때문이라고도 할 수 가 있다. 이 논문은 성공적인 공급사슬 관리(SCM) 추진을 위한 공급사슬 관리(SCM) 관련 이론적 논의와 구축전략과 도입 및 성공사례를 연구 및 분석을 통하여 현상황에 대한 고찰과 개선방안에 대해서 제안해보고자 한다. 성공적인 공급사슬 관리(SCM) 추진을 위한 방안을 논의하기 위해서는 먼저 공급사슬 관리(SCM)에 대한 이론적 배경에 대한 고찰이 필요하다. 따라서 II장에서는 공급사슬 관리(SCM)에 대한 기본적인 개념과 필요성에 대해서 기술하고, III장에서는 현재 추진되고 있는 공급사슬 관리(SCM)에 대한 문제점에 대해서 기술할 것이다. 마지막으로IV, V장에서는 공급사슬 관리(SCM) 구축전략과 LG전자사례 및 결론을 기술할 것이다.

  • PDF