• Title/Summary/Keyword: Open and Closed

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An Investigation on Operating Characteristics of the Closed Cycle System Using High Pressure Diesel Engine (고압 디젤엔진을 이용한 폐회로 시스템의 운전특성에 관한 고찰)

  • 김인교;박신배
    • Transactions of the Korean Society of Automotive Engineers
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    • v.10 no.5
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    • pp.65-72
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    • 2002
  • The closed cycle diesel system is operated in closed circuit system where there is non air breathing with working fluid consists of combination of oxygen, argon and recycled exhaust gas far obtaining underwater or underground power sources. Experimental apparatus using the MTU8V183SE92 high pressurized engine adapted for closed cycle running, capable of operating at the system pressure of maximum 5 bar is constructed with ACAP as data acquisition system in order to operate equally in the open cycle in surface or the closed cycle in submerged conditions. The general features and the characteristics of combustion of HP(high pressure) diesel engine, specially designed and manufactured only for CCDE, are investigated. The test results of performance of HP diesel engine in closed cycle system are presented with respect to power and boost pressure and compared with those of low pressure diesel engine. The oxygen concentration and specific heat ratio are investigated with its deviation

A Closed-form Green마s Function for Top-Covered Microstrip Substrate (Top-Covered 마이크로스트립구조의 Closed-form 그린함수)

  • 김건우;고지환;이영순;조영기
    • Proceedings of the Korea Electromagnetic Engineering Society Conference
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    • 2002.11a
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    • pp.109-112
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    • 2002
  • So far, the closed-form Green's functions have been derived almost for th open microstrip structures. In the present study, closed-form Green's functions for a top-covered microstrip structure are derived. And an effect of top-cover is discussed in comparison with open structure.

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A Pilot MEG Study During A Visual Search Task (시각추적과제의 뇌자도 : 예비실험)

  • Kim, Sung Hun;Lee, Sang Kun;Kim, Kwang-Ki
    • Annals of Clinical Neurophysiology
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    • v.8 no.1
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    • pp.44-47
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    • 2006
  • Background: The present study used magnetoencephalography (MEG) to investigate the neural substrates for modified version of Treisman's visual search task. Methods: Two volunteers who gave informed consent participated MEG experiment. One was 27- year old male and another was 24-year-old female. All were right handed. Experiment were performed using a 306-channel biomagnetometer (Neuromag LTD). There were three task conditions in this experiment. The first was searching an open circle among seven closed circles (open condition). The second was searching a closed circle among seven uni-directionally open circles (closed condition). And the third was searching a closed circle among seven eight-directionally open circles (random (closed) condition). In one run, participants performed one task condition so there were three runs in one session of experiment. During one session, 128 trials were performed during every three runs. One participant underwent one session of experiment. The participant pressed button when they found targets. Magnetic source localization images were generated using software programs that allowed for interactive identification of a common set of fiduciary points in the MRI and MEG coordinate frames. Results: In each participant we can found activations of anterior cingulate, primary visual and association cortices, posterior parietal cortex and brain areas in the vicinity of thalamus. Conclusions: we could find activations corresponding to anterior and posterior visual attention systems.

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LIGHT-REGULATED LEAF MOVEMENT AND SIGNAL TRANSDUCTION IN NYCTINASTIC PLANTS

  • Kim, Hak-Yong
    • Journal of Photoscience
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    • v.4 no.1
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    • pp.23-30
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    • 1997
  • Leaf movements in nyctinastic plants are produced by changes in the turgor of extensor and flexor cells, collectively called motor cells, in opposing regions of the leaf movement organ, the pulvinus. In Samanea saman, a tropical tree of the legume family, extensor cells shrink and flexor cells swell to bend the pulvinus and fold the leaf at night, whereas extensor cells swell and flexor cells shrink to straighten the pulvinus and extend the leaf in the daytime. These changes are caused by ion fluxes primarily of potassium and chloride, across the plasma membrane of the motor cells. These ion fluxes are regulated by exogenous light signals and an endogenous biolgical clock. Inward-directed K$^+$ channels are closed in extensor and open in flexor cells in the dark period, while these channels are open in extensor and closed in flexor cells in the light period. Blue light opens the closed K$^+$ channels in extensor and closes the open them in flexor cells during darkness. Illumination of red light followed by darkness induces to open the closed K$^+$ channels in flexor and to close the open K$^+$ channels in extensor cells in the light. The dynamics of K$^+$ channels in motor cells that are controlled by light signals are consistent with the behavior of the pulvini in intact plants. Therefore, these cell types are an attractive model system to elucidate regulations of ion transports and their signal transduction pathways in plants. This review is focused on light-controlled ion movements and regulatory mechanisms involved in phosphoinositide signaling in leaf movements in nyctinastic plants.

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SOME EXTENSION ON HESITANT FUZZY MAXIMAL, MINIMAL OPEN AND CLOSED SETS

  • M. SANKARI;C. MURUGESAN
    • Journal of applied mathematics & informatics
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    • v.41 no.2
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    • pp.265-272
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    • 2023
  • This article presents a novel notion of hesitant fuzzy cleanly covered in hesitant fuzzy topological spaces;moreover two strong hesitant fuzzy separation axioms are investigated. Based on fuzzy maximal open sets few properties of hesitant fuzzy cleanly covered are obtained. By dint of hesitant fuzzy minimal open and fuzzy maximal closed sets two strong hesitant fuzzy separation axioms are extended.

Symbolic Generation of Dynamic Equations and Modeling of a Parallel Robot (기호 운동방정식 생성과 병렬형 로봇 모델링)

  • Song, Sung-Jae;Cho, Byung-Kwan;Lee, Jang-Moo
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.20 no.1
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    • pp.35-43
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    • 1996
  • A computer program for automatic deriving the symbolic equations of motion for robots using the programming language MATHEMATICA has been developed. The program, developed based on the Lagrange formalism, is applicable to the closed chain robots as well as the open chain robots. The closed chains are virtually cut open, and the kinematics and dynamics of the virtual open chain robot are analyzed. The constraints are applied to the virtually cut joints. As a result, the spatial closed chain robot can be considered as a tree structured open chain robot with kinematic constraints. The topology of tree structured open chain robot is described by a FATHER array. The FATHER array of a link indicates the link that is connected in the direction of base link. The constraints are represented by Lagrange multipliers. The parallel robot, DELTA, having three-dimensional closed chains is modeled and simulated to illustrate the approach.

Open versus closed reduction of mandibular condyle fractures : A systematic review of comparative studies

  • Kim, Jong-Sik;Seo, Hyun-Soo;Kim, Ki-Young;Song, Yun-Jung;Kim, Seon-Ah;Hong, Soon-Min;Park, Jun-Woo
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.34 no.1
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    • pp.99-107
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    • 2008
  • Objective : The objective of this review was to provide reliable comparative results regarding the effectiveness of any interventions either open or closed that can be used in the management of fractured mandibular condyle Patients and Methods : Research of studies from MEDLINE and Cochrane since 1990 was done. Controlled vocabulary terms were used. MeSH Terms were "Mandibular condyle" AND "Fractures, bone". Only comparative study were considered in this review using the "limit" function. According to the criteria, two review authors independently assessed the abstracts of studies resulting from the searches. The studies were divided according to some criteria, and following were measured: Ramus height, condyle sagittal displacement, condyle Towns's image displacement, Maximum open length, Protrusion & Lateral excursion, TMJ pain, Malocclusion, and TMJ disorder. Results : Many studies were analyzed to review the post-operative result of the two methods of treatment. Ramus height decreased more in when treated by closed reduction as opposed to open reduction. Sagittal condyle displacement was shown to be greater in closed reduction. Condyle Town's image condyle displacement had greater values in closed reduction. Maximum open length showed lower values in closed reduction. In protrusive and lateral movement, closed reduction was less than ORIF. Closed reduction showed greater occurrence of malocclusion than ORIF. However, post-operative pain and discomfort was greater in ORIF. Conclusion : In almost all categories, ORIF showed better results than CRIF. However, the use of the open reduction method should be considered due to the potential surgical morbidity and increased hospitalization time and cost. To these days, Endoscopic surgical techniques for ORIF (EORIF) are now in their infancy with the specific aims of eliminating concern for damage to the facial nerve and of reducing or eliminating facial scars. Before performing any types of treatment, patients must be understood of both of the treatment methods, and the best treatment method should be taken on permission.

The usage motivation of SNS: A Comparison of Open type and Closed type SNS (SNS의 이용 동기에 관한 연구: 개방형 SNS와 폐쇄형 SNS의 비교)

  • Jun, Byoungho
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.11 no.2
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    • pp.181-192
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    • 2015
  • A new communication revolution such as social networking service (SNS) has been transforming the way of interaction between people in both of individual level and organizational level. Recently many people have switched to closed type SNS such as Naver Band and Kakao group due to the several reasons. The purpose of this study is to investigate the usage motivation and satisfaction of SNS based on use and gratifications perspectives. Based on prior studies on use and gratifications of Internet-related media and SNS, information motivation, relationship motivation, pleasure/entertainment motivation, self-expression motivation, work motivation were identified as usage motivation of SNS. This empirical study explores how these motivations vary between open type SNS(facebook and twitter) and closed type SNS(band and kakao group). This study contributes to provide the base of activation strategies and practical implications for companies using SNS as a marketing tool.

Open versus closed treatment for extracapsular fracture of the mandibular condyle

  • Lee, Junyeong;Jung, Hee-Yeoung;Ryu, Jaeyoung;Jung, Seunggon;Kook, Min-Suk;Park, Hong-Ju;Oh, Hee-Kyun
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.48 no.5
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    • pp.303-308
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    • 2022
  • Objectives: Selection of treatment methods for mandibular condylar fractures remains controversial. In this study, we investigated treatment methods for condylar fractures to determine the indications for open or closed reduction. Patients and Methods: Patients >12 years of age treated for mandibular condylar fractures with a follow-up period of ≥3 months were included in this study. The medical records of enrolled patients were reviewed for sex, age, fracture site, treatment method (open or closed reconstruction), postoperative intermaxillary fixation period, operation time, and complications. Radiological analysis of fracture fragment displacement and changes in ramal height difference was performed using computed tomography and panoramic radiography. Results: A total of 198 patients was investigated, 48.0% (n=95) of whom underwent closed reduction and 52.0% (n=103) underwent open reduction. There was no significant correlation between reduction method and patient sex, age, or follow-up period. No statistically significant difference between the incidence of complications and treatment method was observed. None of the patients underwent open reduction of condylar head fracture. Binary logistic regression analysis showed that open reduction was significantly more frequent in patients with subcondylar fracture compared to in those with a fracture in the condylar head area. There was no statistically significant correlation between the groups and fracture fragment displacement. However, there was a significant difference between the treatment groups in amount of change in ramal height difference between the fractured and the non-fractured sides during treatment. Conclusion: No significant clinical differences were found between the open and closed reduction methods in patients with mandibular condylar fractures. According to fracture site, closed reduction was preferred for condyle head fractures. There was no significant relationship between fracture fragment displacement and treatment method.