• Title/Summary/Keyword: changing point

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A study on electrical characteristics of ceramics capacitor for temperature compensation (온도보상용 세라믹 커패시터의 전기적 특성에 관한 연구)

  • 홍경진;정우성;김태성;이은학;이준웅
    • Electrical & Electronic Materials
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    • v.8 no.5
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    • pp.640-647
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    • 1995
  • In this study, the BaTiO$\sub$3/ capacitor add to MnO$\sub$2/ like depressor and shifter were investigated for temperature or voltage compensation by structural and electrical analysis. The relative density of BCTM, generating poly crystall and formation of lattice defect, has a 90[%] over as the CaTiO$\sub$3/ come out to control grain size. The current density of BCTM2 increased non-ohmic in high-electric field but that BCTM3 and BCTM4 had a few changing. The BCTM3 and BCTM4 unformated grain boundary shown temperature compensation properties, so that the dielectric constant was low value. The curie point was near 140[.deg. C] in BCTM1 and BCTM4, but BCTM3 and BCTM4 not shown the curie point. It is found that the charging energy of BCTM4 was changed 6[%] according to rising temperature from room temperature to 417[K]. The formation of BaMnO$\sub$3/ was low dielectric constant to change frequency and temperature.

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Analysis of various MPPT algorithms for PCS (태양광 발전시스템의 MPPT 알고리즘 분석)

  • Shim, Jae-Hwe;Yang, Seung-Dae;Jung, Seung-Hwan;Choi, Ju-Yeop;Choy, Ick;An, Jin-Ung;Lee, Dong-Ha
    • Journal of the Korean Solar Energy Society
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    • v.31 no.2
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    • pp.16-21
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    • 2011
  • Since the maximum power operating point(MPOP) of PCS alters with changing atmospheric conditions temperature conditions shadow conditions it is important to operate for PCS to keep maximum power point tracking(MPPT) continuously. This paper presents the results of modeling PV system by PSIM simulator and investigates the influence on the PV system from aspect of power quality i.e. voltage drop. This paper investigates four MPPT algorithms; Perturbation & Observation(P&O) Improved P&O Incremental Conductance(Incond) Differential coefficient method simulated with irradiation temperature change and shadow conditions.

The Prediction of the Apartment Construction Project Cashflow with Changing Sales Point (분양시기 변동에 따른 공동주택 건설공사 현금흐름 예측)

  • Bae Jun-Ho;Kim Jae-Jun
    • Proceedings of the Korean Institute Of Construction Engineering and Management
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    • autumn
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    • pp.234-237
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    • 2003
  • The Korean housing supply have been provided by the Pre-construction sales system. The Pre-construction sales system contributed to large housing supply. But it followed by the market anomaly. Along the housing market is changing to tile market for consumers, it requires new policy and regulations. This market changes and needs to modify the policy make a discussion about introducing the Post-construction sales system. it concerns to change the time to sale. This paper analyzes the present feasibility study and makes a tool to predict construction cashflow considering changed sales point. The sales timing leads to decide the amount of financial costs in the construction project and that cost affects to the feasibility. The accurate cashflow prediction is required for a successful apartment construction delivery.

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Clinical Comparison Studies on Bell's Palsy Patients by Existence of Postauricural Pain (이후통과 Bell's palsy의 예후와의 상관성 연구)

  • Hwang, Ji-Hye;Lim, Dae-Jung;Lee, Hyun-Jin;Cho, Hyun-Seok;Kim, Kyung-Ho;Kim, Seung-Hyeon
    • Journal of Acupuncture Research
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    • v.23 no.6
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    • pp.9-18
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    • 2006
  • Objectives : This study was designed to evaluate the influence of postauricular pain on Bell's palsy patients. Methods : We investigated 71 cases of patients with Bell's palsy and classified them as existence of Postauricural pain, 71 patients were sequentially interviewed and examined. We evaluated the treatment effect of each group by using Gross Grading System of House-Brackmann(H-B grade) before treatment and after final treatment and we researched differences of sequelae of Bell's palsy, period of treatment, changing point -period from onset of Bell's palsy to the day which the change begins to be seen at the face- and improvement -period which Bell's palsy is improved from onset to H-B gradeII. Results : 1. In age, sex, lesion, duration of disease, we found that two groups have no significant differences. 2. In improvement and period of treatment, we found that two groups have significant differences. In changing-point, we found that two groups had the difference of the average, but they were not statistically significant. 3. As a result of evaluation by using H-B grade, treatment score after final treatment was marked higher than that before treatment within each group. 4. After final treatment, Non-postauricular pain group had significant difference(result) on H-B grade compared with Postauricular pain group. 5. In frequency of sequelae symptoms of Bell's palsy, Postauricular pain group had more higher compared with Non-postauricular pain group. Conclusion : These results suggested that Non postauricular pain group should be get better than Postauricular pain group.

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Wide-range Speed Control Scheme of BLDC Motor Based on the Hall Sensor Signal

  • Lee, Dong-Hee
    • Journal of Power Electronics
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    • v.18 no.3
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    • pp.714-722
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    • 2018
  • This paper presents a wide-range speed control scheme of brushless DC (BLDC) motors based on a hall sensor with separated low- and normal-speed controllers. However, the use of the hall sensor signal is insufficient to detect motor speed in the low-speed region because of low sensor resolution and time delay. In the proposed method, a micro-stepping current control method according to the torque angle variation is presented. In this mode, the motor current frequency and rotating angle are determined by the reference speed without the actual speed fed by the hall sensor. The detected torque angle is used to adjust the current value in a limited band to control the current value in accordance with the load. The torque angle is detected exactly at the changing point of the hall sensor signal. The rotor can follow the rotating flux with the variable torque angle. In a normal speed range, the conventional vector control scheme is used to control the motor current with a PI speed controller using the hall sensor. The torque characteristics are analyzed on the basis of the back EMF and current shape. To adopt the vector control scheme, the continuous rotor position is estimated by the measured speed and hall sensor position. At the mode changing point between low and normal speed range, the proper initial current command and reference rotor position are calculated. The calculated current command can reduce the torque ripple during transient mode. The proposed method is simple but effective in extending the speed control range of a conventional BLDC motor with hall sensor without the need for a high-resolution encoder. The effectiveness of the proposed method is verified by various experiments on a practical BLDC motor.

Analysis of Changes in Residents' Perception to Establish Resident-driven Management System for Rural Nonpoint Pollution Sources - Rural field forum process - (농촌 비점오염의 주민주도 관리체계 마련을 위한 주민 의식 변화 분석 - 농촌현장포럼 프로세스를 중심으로 -)

  • Na, Kyung Soo;Kim, Jong gun;Lim, Kyoung Jae;Kim, Ki Sung
    • Journal of Korean Society of Rural Planning
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    • v.25 no.4
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    • pp.47-56
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    • 2019
  • More than half of the nonpoint sources of polluting water occur in cultivating farmlands in rural areas. Agricultural nonpoint sources are discharged from large areas of farmlands, making it difficult to collect or treat pollutants. Farmland source management is known to be the most effective, and preventive management by improving farming methods is the key to reduce nonpoint pollution. At present, more than 30% of the pollutants flowing into the rivers and lakes are nonpoint pollutants caused by agricultural activities. As a countermeasure, it is more preferable to develop and apply optimal farming management techniques for agricultural nonpoint pollution management basically than to apply existing water quality management techniques. Because of the characteristics of nonpoint source pollution, it is necessary to manage farmlands in rural areas, so the willingness and competence of the residents is most important. The purpose of this study is to analyze and understand the process of changing the cognition of residents through capacity education and survey for nonpoint pollution management in rural areas. This study conducted intensive resident competency education and examined the process of changing resident awareness through three surveys. As a result of this study, it was found that continuous education and activities for rural non-point pollution management are necessary for raising awareness of residents and managing non-point pollution effectively, showing possibility of change residents' perception.

Development of a Driver Safety Information Service Model Using Point Detectors at Signalized Intersections (지점검지자료 기반 신호교차로 운전자 안전서비스 개발)

  • Jang, Jeong-A;Choe, Gi-Ju;Mun, Yeong-Jun
    • Journal of Korean Society of Transportation
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    • v.27 no.5
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    • pp.113-124
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    • 2009
  • This paper suggests a new approach for providing information for driver safety at signalized intersections. Particularly dangerous situations at signalized intersections such as red-light violations, accelerating through yellow intervals, red-light running, and stopping abruptly due to the dilemma zone problem are considered in this study. This paper presents the development of a dangerous vehicle determination algorithm by collecting real-time vehicle speeds and times from multiple point detectors when the vehicles are traveling during phase-change. For an evaluation of this algorithm, VISSIM is used to perform a real-time multiple detection situation by changing the input data such as various inflow-volume, design speed change, driver perception, and response time. As a result the correct-classification rate is approximately 98.5% and the prediction rate of the algorithm is approximately 88.5%. This paper shows the sensitivity results by changing the input data. This result showed that the new approach can be used to improve safety for signalized intersections.

A Study on Zen Fashion in the Point of View of Culture Transition (문화(文化) 전이(轉移)(culture transition)의 시각(視覺)에서 본 젠(禪) 패션 연구(硏究))

  • Park, Hye-Won
    • Journal of Fashion Business
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    • v.4 no.1
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    • pp.73-85
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    • 2000
  • The purpose of this study is for considering about Zen fashion in the point of view of culture transition. Through this research, the Far-East including Korea will be confirmed as a center of fashion culture in 21st century. The contents are the meaning of culture transition in Post Modern period, the meaning of Zen and changing of fashion trend as the background of Zen Fashion, and the characteristics of Zen fashion design. The results are as follows: Anti-western movement or dismantlement of culture has been represented the limitation of western centered culture. So the interesting about East means the changing to east from west in ideas. To make new creation in fashion field, the comprehension about the western fashion which has been preceeded and new trials using the our tradition will be needed. Zen is a kind of Buddhism and the essence of it is to find myself and express individual experiences. The change of one's sens of value, new age movement and concerning of environment and ecology make more comfortable, simple and healthy elements in clothing. The fusion style is under a vogue in life style and Zen is the core of this trend. The characteristics of Zen fashion are flat dismantlement which has been know as a Japanese style, oriental minimalism and nature beauty of ecology. This characteristics are found not only the shape, color but the will of the behind. The pursing temperance and naturalism are represented the fashion culture transition from the West to Far-East. Therefore multi points of fashion research is very important and the identify about Korean fashion is required in lately for new fashion paradigm.

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Changing trends in clinico-pathologic characteristics and treatment outcomes in patients with gastric cancer: A single-center, public hospital, retrospective study

  • Gwak, Min-Seung;Park, Jong-Min
    • Korean Journal of Clinical Oncology
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    • v.14 no.2
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    • pp.69-75
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    • 2018
  • Purpose: We analyzed our 10-year experience in a single-center, public hospital and thereby evaluated the changing trends of clinico-pathologic and surgical characteristics as well as treatment outcomes in patients with gastric cancer. Methods: The current single-center, retrospective study was conducted with patients who had been treated at department of our medical institution during a period ranging from March 1, 2007 to June 16, 2018. The eligible patients were divided into two groups: group I (March 2007-April 2012) and II (May 2012-June 2018). Then, we compared time-dependent changes in clinico-pathologic characteristics between the two groups. Results: The mean age was $63.0{\pm}11.3$ years in group I and $65.8{\pm}10.5$ years in group II, respectively (P=0.017). The American Society of Anesthesiologist (ASA) score was 34.9% for 1 point, 38.3% for 2 points, and 26.9% for 3 points or more in group I, and 31.1% for 1 point, 52.5% for 2 points, and 16.4% for 3 points or more in group II, which was statistically significant (P=0.012). The average follow-up duration was significantly different between the two group ($39.8{\pm}39.7$ vs. $23.4{\pm}20.6$) (P<0.001). The duration of postoperative hospital stay was 1.8 days longer in group II than group I (P=0.047). Tumor depth, node metastasis and distant metastasis were significantly different between the two groups (P<0.001, P=0.009, and P=0.019, respectively). Conclusion: There were significant differences in the age, ASA score, average follow-up duration, postoperative hospital stay, tumor depth, node metastasis and distant metastasis between the two groups.

Study for Understanding the Special Character and the Tendency of Movement Change in Twelve Meridians (12 경락(經絡)의 속성(屬性)과 운동변화(運動變化)의 경향성(傾向性)을 파악(把握)하기 위한 연구(硏究))

  • Shuk Dong-Yun;Choi Chan-Hun;Jang Kyeong-Seon
    • Korean Journal of Acupuncture
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    • v.17 no.1
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    • pp.123-140
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    • 2000
  • The purpose of this study is to understand the special character and the tendency of the movement change that 12 meridians possess. We studied about the incidental and fundamental rule of the six atmospheric influence that was presented by Pyobonjoong(the incidental, fundamental, intermediate) theory, and the Hwang won-uh's the Six Channel activity of the Qi theory that presented movement form of the meridian through the six atmospheric influence. Then we found the following substances. The Pyobonjoong(the incidental, fundamental, intermediate) theory is applicable to understand the special character and the tendency of the movement change that Meridians possess. But, because the Pyobonjoong(the incidental, fundamental, intermediate) theory can't classify the characteristic difference of the hand and foot meridians, then the principle that can devide the meridians of the hand and foot, must be supplied. The Jungwha(right changing)-Daewha(opposite changing) theory is able to concretely classify the special character of the hand and foot six meridians. And Hwang's Shawha(superintending change)-Jongwha(following change) theory that is base on Jungwha(right changing)-Daewha(opposite changing) theory, is able to classify the special character of the hand and foot six meridians, too. If the concept of the Meridians is understood by the Shawha(superintending change)-Jongwha(following change) theory, the special character of the hand and foot six meridians could be concretely classified and then the meridian of the Bowels and the six atmospheric influence corresponded to the meridians could be expansively explained as the point that take charge and control these special Qi in the human body The Bon-Qi(fundamental Qi) act on the special character of Shawha(superintending change) six meridians and the tendency of the movement change is cause by the insufficiency and excessiveness of the Bon-Qi(fundamental Qi). The Qi of the Shawha(superintending change) meridians act on the special character of Jongwha(following change) six meridians and the tendency of the movement change is cause by the exuberance of Yang and the deficiency of Yang.

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