• Title/Summary/Keyword: Sharing current control

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A Buck-Boost Type Charger with a Switched Capacitor Circuit

  • Wu, Jinn-Chang;Jou, Hurng-Liahng;Tsai, Jie-Hao
    • Journal of Power Electronics
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    • v.15 no.1
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    • pp.31-38
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    • 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
    • International conference on construction engineering and project management
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    • 2017.10a
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    • pp.301-312
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    • 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.

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Holographic Recording Versus Holographic Lithography

  • Seungwoo Lee
    • Current Optics and Photonics
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    • v.7 no.6
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    • pp.638-654
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    • 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.

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

  • Jeong, Him-Chan;Kim, Tae-Young;Kim, Yong;Oh, Hyo-Jung
    • Journal of the Korean Society for information Management
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    • v.34 no.2
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    • pp.137-158
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    • 2017
  • Disaster has a direct influence on the lives of the people, the body, and the property. For effective and rapid disaster responses, coordination process based on sharing and utilizing disaster information is the essential requirement Disaster and safety control agencies produce and manage heterogeneous information. They also develop and use word dictionaries individually. This is a major obstacle to retrieve and access disaster and safety information in terms of practitioners. To solve this problem, standardization of lexical resources related disaster and safety is essentially required. In this paper, we conducted current status analysis about lexical resources in disaster and safety domain. Consequently, we identified the characteristics according to lexical groups. And then we proposed the utilization plan of lexical resources for disaster and safety information management.

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

  • Lee Hee-Chang;Park Sung-Jun;Park Soo-Sik;Moon Chae-Joo;Lee Man-Hyung;Kim Jong-Dal
    • The Transactions of the Korean Institute of Power Electronics
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    • v.9 no.5
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    • pp.457-466
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    • 2004
  • In this paper, a modified converter is presented and analyzed to use as a photovoltaic converter. And also a new parallel driving scheme is proposed to increase output power and to reduce the output voltage ripple. The ratio of the output to the input voltage of the modified converter is equal to that of the boost converter. The difference between both converters is the composition of output terminal. Owing to the discrepancy, a working voltage of the output capacitor of the modified converter becomes lower, thus the capacitance value of the capacitor can be smaller than that of the boost converter. The proposed parallel driving is based on the modified converter and a current-mode-control method. It gives a good solution for alleviating the current sharing unbalance problem of conventional parallel operations. It reduces the output voltage ripple by means of increasing the equivalent switching frequency without additional switching losses. The validity of the proposed parallel driving strategy is verified through computer-aided simulations and experimental results.

Recommendation Model for Battlefield Analysis based on Siamese Network

  • Geewon, Suh;Yukyung, Shin;Soyeon, Jin;Woosin, Lee;Jongchul, Ahn;Changho, Suh
    • Journal of the Korea Society of Computer and Information
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    • v.28 no.1
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    • pp.1-8
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    • 2023
  • In this paper, we propose a training method of a recommendation learning model that analyzes the battlefield situation and recommends a suitable hypothesis for the current situation. The proposed learning model uses the preference determined by comparing the two hypotheses as a label data to learn which hypothesis best analyzes the current battlefield situation. Our model is based on Siamese neural network architecture which uses the same weights on two different input vectors. The model takes two hypotheses as an input, and learns the priority between two hypotheses while sharing the same weights in the twin network. In addition, a score is given to each hypothesis through the proposed post-processing ranking algorithm, and hypotheses with a high score can be recommended to the commander in charge.

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
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    • v.3 no.4
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    • pp.363-369
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    • 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.

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

  • Kim, Kyu-Sik;Park, Eun-Sun;Kim, Seung-Seok;Kim, Hyung-Woo;Kim, Young-Chul;Bom, Hee-Seung;Ahn, Sung-Ja;Na, Kook-Joo;Kim, Yun-Hyeon;Kim, Yu-Il;Lim, Sung-Chul;Moon, Jai-Dong
    • Tuberculosis and Respiratory Diseases
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    • v.59 no.5
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    • pp.480-486
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    • 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.

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

  • Shin, Narae;Xu, Dayuan;Song, Jun Kyung;Park, Jaebum
    • Korean Journal of Applied Biomechanics
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    • v.29 no.3
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    • pp.157-166
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    • 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.

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

  • Lee, Gi-Wan;Lee, Sang-Youn
    • Journal of Distribution Science
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    • v.9 no.3
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    • pp.83-94
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    • 2011
  • Most domestic companies, with the exclusion of major firms, are reluctant to implement a supply chain management (SCM) network into their operations. Most small- and medium-sized enterprises are not even aware of SCM. Due to the inherent total-systems efficiency of SCM, it coordinates domestic manufacturers, subcontractors, distributors, and physical distributors and cuts down on cost of inventory control, as well as demand management. Furthermore, a lack of SCM causes a decrease in competitiveness for domestic companies. The reason lies in the fundamentality of SCM, which is the characteristic of information sharing, process innovation throughout SCM, and the vast range of problems the SCM management tool is able to address. This study suggests the contemplation and reformation of the current SCM situation by analyzing the SCM strategic plan, discourses and logical discussions on the topic, and a successful case for adapting SCM; hence, the study plans to productively "process" SCM. First, it is necessary to contemplate the theoretical background of SCM before discussing how to successfully process SCM. I will describe the concept and background of SCM in Chapter 2, with a definition of SCM, types of SCM promotional activities, fields of SCM, necessity of applying SCM, and the effects of SCM. All of the defects in currently processing SCM will be introduced in Chapter 3. Discussion items include the following: the Bullwhip Effect; the breakdown in supply chain and sales networks due to e-business; the issue that even though the key to a successful SCM is cooperation between the production and distribution company, during the process of SCM, the companies, many times, put their profits first, resulting in a possible defect in demands estimation. Furthermore, the problems of processing SCM in a domestic distribution-production company concern Information Technology; for example, the new system introduced to the company is not compatible with the pre-existing document architecture. Second, for effective management, distribution and production companies should cooperate and enhance their partnership in the aspect of the corporation; however, in reality, this seldom occurs. Third, in the aspect of the work process, introducing SCM could provoke corporations during the integration of the distribution-production process. Fourth, to increase the achievement of the SCM strategy process, they need to set up a cross-functional team; however, many times, business partners lack the cooperation and business-information sharing tools necessary to effect the transition to SCM. Chapter 4 will address an SCM strategic plan and a case study of LG Electronics. The purpose of the strategic plan, strategic plans for types of business, adopting SCM in a distribution company, and the global supply chain process of LG Electronics will be introduced. The conclusion of the study is located in Chapter 5, which addresses the issue of the fierce competition that companies currently face in the global market environment and their increased investment in SCM, in order to better cope with short product life cycle and high customer expectations. The SCM management system has evolved through the adaptation of improved information, communication, and transportation technologies; now, it demands the utilization of various strategic resources. The introduction of SCM provides benefits to the management of a network of interconnected businesses by securing customer loyalty with cost and time savings, derived through the consolidation of many distribution systems; additionally, SCM helps enterprises form a wide range of marketing strategies. Thus, we could conclude that not only the distributors but all types of businesses should adopt the systems approach to supply chain strategies. SCM deals with the basic stream of distribution and increases the value of a company by replacing physical distribution with information. By the company obtaining and sharing ready information, it is able to create customer satisfaction at the end point of delivery to the consumer.

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