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고슬립을 이용한 6 륜구동/6 륜조향 차량 고장 안전 주행 제어 (Fault-Tolerant Driving Control of Independent Steer-by-Wire System for 6WD/6WS Vehicles Using High Slip)

  • 나재원;김원균;이경수;이종석;이대옥
    • 대한기계학회논문집A
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    • 제37권6호
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    • pp.731-738
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    • 2013
  • 본 논문은 6 륜 독립구동/독립조향 차량의 독립 스티어-바이-와이어 장치의 고장 안전 주행 제어방법을 제시하였다. 조향부 고장 휠의 횡방향 타이어 힘이 차량 선회 운동에 저항력으로 작용할 수 있으므로, 이를 줄이기 위하여 본 고장 안전 주행 제어 알고리즘은 조향부 고장 휠에 높은 슬립률이 발생하도록 토크 입력을 가한다. 고슬립으로 인한 조향부 고장 휠의 종방향 타이어 힘 증가를 고려하기 위하여 종방향 타이어 힘을 추정하여 고장나지 않은 휠의 구동력 최적 분배에 구속 조건에 포함시킨다. 개루프 조향 및 폐루프 조향 시뮬레이션 결과 조향부 고장이 발생한 차량의 주행시 고장을 고려하지 않은 최적 구동력 분배 제어에 비하여 본 알고리즘 적용시 차량의 주행 성능이 보정됨을 확인하였다.

케이블 공진을 이용한 600V 제어/계측용 꼬임쌍선 차폐 케이블의 열화상태 진단에 대한 연구 (A Study on the Deterioration Diagnosis of 600V Shielded Twisted Pair Control/Measurement Cable using Resonance Frequency)

  • 신재영;김광호;나완수
    • 전기학회논문지
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    • 제64권12호
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    • pp.1768-1775
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    • 2015
  • Recent major domestic facilities, such as nuclear power plants, many control cables are installed and are degraded by long-term use, but research on deterioration diagnosis is lacking. In the event of a fault in the cable due to deterioration can be developed into a major accident such as the main plant is stopped, so the deterioration diagnostic techniques of high reliability for the cable is required. In this paper, proposes a methodology using a cable resonance that can effectively diagnose the deterioration of the cable. Prior to the test, we developed a setup for stable measuring the characteristics of the cable and it verified the suitable of the measurement set-up in terms of interactivity and reliability, also measured S-parameters applying verified measurement set-up to the cables that deterioration degree is different. Then, we had amplified the difference in resonance frequency between the healthy state and the deteriorated state using connection in a series of measured S-parameters. In a result from the method, we have verified that the more deteriorate the cables is, the more decrease the resonance frequency is. Measured results are justified by inducing the resonance frequency calculation of the cable from the S- parameters represented by the hyperbolic function formula. VNA(Vector Network Analyzer) for S-parameter measurements used in this study is Agilent E5061B and shielded twisted-pair cables was used for deterioration diagnostic test.

키르키즈스탄 이주민 마을 지역사회기반 영유아 건강증진 예비사업 평가 (Evaluation of a Community-based Child (Infants and Toddlers) Health Promotion Pilot Project in a Migrant Village in Kyrgyzstan)

  • 신현숙;이유나;이숙정;장윤경
    • Child Health Nursing Research
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    • 제25권4호
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    • pp.406-416
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    • 2019
  • Purpose: Children in migrant villages in Kyrgyzstan have a high incidence of anemia and need effective health promotion programs. The purpose of this study was to evaluate a pilot study of a health promotion project for infants and toddlers based on community participation. Methods: This was a retrospective study conducted to evaluate the effectiveness of the project. The project was carried out by nurses at a public health center, community health workers, and local residents in a migrant village. After the operational system of the project was established, health assessments, child-care education, provision of vouchers for iron supplements, and activities to improve residents' awareness were conducted during 6 months among 100 children, of whom 85 were finally analyzed. Results: In international health projects, close cooperation of the project team with community residents and health workers is important. Access to the community-based program was feasible in the socially and economically poor migrant village, and improvements were shown in children's anemia and awareness of health care. Conclusion: By focusing on the effective aspects of this preliminary project, plans to utilize community health workers and promotion strategies can be added to the main project to improve health promotion among children in this area.

신축성있는 Ag 나노와이어 전극의 제조 및 전기변색 응용 (Fabrication of Stretchable Ag Nanowire Electrode and its Electrochromic Application)

  • 이진영;한송이;나윤채;박종운
    • 한국재료학회지
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    • 제29권2호
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    • pp.87-91
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    • 2019
  • We report on stretchable electrochromic films of poly(3-hexylthiophene) (P3HT) fabricated on silver nanowire (AgNW) electrodes. AgNWs electrodes are prepared on polydimethylsiloxane (PDMS) substrates using a spray coater for stretchable electrochromic applications. On top of the AgNW electrode, poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) is introduced to ensure a stable resistance over the electrode under broad strain range by effectively suppressing the protrusion of AgNWs from PDMS. This bilayer electrode exhibits a high performance as a stretchable substrate in terms of sheet resistance increment by a factor of 1.6, tensile strain change to 40 %, and stretching cycles to 100 cycles. Furthermore, P3HT film spin-coated on the bilayer electrode shows a stable electrochromic coloration within an applied voltage, with a color contrast of 28.6 %, response time of 4-5 sec, and a coloration efficiency of $91.0cm^2/C$. These findings indicate that AgNWs/PEDOT:PSS bilayer on PDMS substrate electrode is highly suitable for transparent and stretchable electrochromic devices.

식공간의 실용 연출과 예술 연출의 차이 분석 (Analysis of Difference between Utility Presentation and Art Presentation in Food Space)

  • 계수경;유한나
    • 동아시아식생활학회지
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    • 제20권4호
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    • pp.619-627
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    • 2010
  • Finality in presenting table has an important significance. A presentation method in table comes to have different directionality depending on objective and significance such as the appearance of presentation for the substantial use or the appearance of presentation for delivering message. In our life, the utility table came to have value more than what supplies nutrition. Simultaneously with it, the table came to have the significance as a place of communication. What is being indicated in a different form from this is the art table. The table-coordinate starts to occupy a position in one aesthetic sphere, aside from the functional part of having a meal and communication, and is attempting the entry as the art sphere. What two types have been researched and developed so far in the face of having clear difference is limited to the utility presentation. The utility presentation and the art presentation need to be progressed at the same time rather than being separately classified and thought. Pursuit only for utility leads to being unable to proceed with making a new thing. The art table coordinate will be able to function as the new awakening point in the position of proceeding with such table coordinate. When proceeding with maintaining the form of the existing utility table, a client fails to feel fresh. Thus, coming to give new awareness by integrating art will lead to being available effectively for creating another profit. Even the art table can apply the characteristic of the display table among characteristics of the utility table. The display table aims at creating profit through communication between buyer and seller. Thus, even through the art table, both effects called the occurrence in profit and the initiative in trend will be capable of being enjoyed totally. Accordingly, the presentation of two tables in the art table and the utility table has clearly different characteristic. However, given properly using difference in presentation of the two, the best effect will be possibly seen.

Association Between Atrial Fibrillation and the Risk of Dementia in the Korean Elderly: A 10-Year Nationwide Cohort Study

  • Nah, Min-Ah;Lee, Kyeong Soo;Hwang, Tae-Yoon
    • Journal of Preventive Medicine and Public Health
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    • 제53권1호
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    • pp.56-63
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    • 2020
  • Objectives: The objective of this study was to determine the effect of atrial fibrillation (AF) on the risk of dementia in the Korean elderly. Methods: A 10-year retrospective cohort study was conducted using the National Health Insurance Service-Senior Cohort database. We excluded those who were under 65 years of age as of January 2006 (n=46 113), those who were diagnosed with dementia between 2002 and 2005 (n=9086), and those with a history of stroke prior to AF diagnosis (n=8392). We used a Cox proportional hazards model with a time-varying covariate to determine whether AF is associated with the risk of dementia after adjusting for potential confounders. Results: In univariable Cox regression, the hazard ratio (HR) of dementia according to AF status was 1.28 (95% confidence interval [CI], 1.23 to 1.33). After adjusting for potential confounders, AF was found to increase the risk of dementia (HR, 1.12; 95% CI, 1.07 to 1.17), Alzheimer dementia (HR, 1.12; 95% CI, 1.07 to 1.17), and vascular dementia (HR, 1.10; 95% CI, 1.03 to 1.18). In patients diagnosed with AF, the incidence of dementia was lower (HR, 0.50; 95% CI, 0.47 to 0.52) in patients who were treated with oral anticoagulants. Conclusions: Investigating the potential risk factors of dementia in an aged society is important. We found a slightly higher risk of dementia in those with AF than in those without AF, and we therefore concluded that AF is a potential risk factor for dementia.

한의치료로 호전되었던 사지마비, 운동실조, 인지저하를 호소하는 베르니케 뇌병증 환자 증례보고 1례 (A Case Report of a Patient with Wernicke's Encephalopathy Complaining of Quadriplegia, Ataxia, and Impaired Cognition Improved by Korean Medicine Treatment)

  • 심상송;이현승;안재윤;채한나;윤종민;문병순
    • 대한한방내과학회지
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    • 제41권5호
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    • pp.777-786
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    • 2020
  • Background: This study is a report on a case of a Wernicke's encephalopathy with quadriplegia, ataxia, and impaired cognition, whose condition was improved by Korean medicine treatment. Case report: A 51-year-old man diagnosed with Wernicke's encephalopathy was treated with acupuncture, Banhabakchulchunma-tang mixed with Ondam-tang-gami (半夏白朮天麻湯合溫膽湯加味), cupping, moxibustion, and rehabilitation. Clinical symptoms were measured with the Manual Muscle Test (MMT), Berg Balance Scale (BBS), Korean Mini Mental Status Exam (K-MMSE), Functional Independence Measure (FIM), Modified Barthel Index (MBI), and a numeric rating scale (NRS). After 22 days of treatment, his clinical symptoms showed improvement. The motor function improved (MMT Rt. side Gr. 4+G/4+G, Lt. side Gr. 4G/4+G → Rt. side Gr. 5-N/4+G, Lt. side Gr. 5-N/4+G), Ataxia was relieved (BBS 3→33), cognition improved (K-MMSE 15→27), ADL scores showed improvement (FIM 58→90, MBI 40→75), and the NRS score decreased for headache (3→0). Conclusion: Korean medicine treatment could be effective in the treatment of patients with Wernicke's encephalopathy.

치과기공사의 셀프리더십 전략유형 - 경남지역을 중심으로 - (Self-Leadership Strategy Styles of Dental Technicians - Focused on Gyeongnam region -)

  • 나정숙
    • 대한치과기공학회지
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    • 제31권3호
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    • pp.47-58
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    • 2009
  • Self-leadership means a person's ability to make his thought or behavior in a right way by controlling it himself. Strategies of the same leadership can be largely categorized into three, behavior focused, natural reward and constructive thought strategies. In this study, the foresaid styles of self-leadership strategy are discussed from the perspective of dental lab laboratories' business environment of Gyeongnam region. And accordingly, this researcher examined such strategy styles that dental lab managers, chief technicians and assistant technicians usually have. Results of the study can be summarized as follows. First, out of the self-leadership strategy styles, most remarkably found among the professional of dental technology was constructive thought strategy, followed by behavior-focused and natural reward strategies in order. In general, therefore, the professionals strongly tend to make their thoughts that can a positive effect on their work performance or in a constructive way. In other words, professional dental technicians are more likely to make efforts to persuade or persuade themselves to change their own unreasonable confidence or negative process in more positive way. Second, the extent to which constructive thought strategy is perceived was not different among dental lab managers, chief technicians and assistant technicians. While, behavior-focused and natural reward strategies were found most strongly perceived by dental lab managers, followed by chief and assistant technicians in order. This may be attributed to the fact that the higher professional dental technicians are in position, the higher they are in self-leadership, or in the ability to overcome crises by themselves and make their thought or behavior in a right way. Dental lab managers usually have lots of experiences in relation to behavior-focused or natural reward strategy. Therefore, they are very strongly capable of controlling themselves in order to overcome crises or make their thought or behavior in a right way. In contrast, assistant technicians are still having lots of trials and errors because they are less experienced and skilled. This suggests that chief technicians should make themselves fully capable as a medium that connects between dental lab managers and assistant technicians.

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전극의 용량성분을 이용한 공진이득 증폭형 유전가열장치에 관한 연구 (A study on a dielectric heating system for amplifying the resonant gain using the capacitance of electrodes)

  • 김신효;이창우;배한나;조대권
    • Journal of Advanced Marine Engineering and Technology
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    • 제39권9호
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    • pp.940-946
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    • 2015
  • 본 논문에서는 300kHz 이상의 주파수를 사용하는 고전압펄스의 출력이득을 증폭시키는 방법에 대하여 고찰하였다. 종래의 파워스테이지의 전압을 상승시켜 펄스진폭(Pulse-amplitude)을 증폭하는 방식 대신에, 부하의 용량성분과 회로의 기생성분간의 공진을 이용하여 출력이득을 증폭하는 방식으로 연구가 진행되었다. 특히 브릿지형 대신에 Flyback Topology를 적용을 통하여 회로구성을 간소화하고, 출력펄스파형에 출력전극의 용량성분을 부여함에 따라 부하에 가해지는 출력전압의 이득을 증폭시킴으로써, 하드스위칭을 통한 출력회로 내에서의 과부하 및 발열에 따른 손상을 막을 수 있는 장점이 있다. 해당연구는 의료 및 산업용가열분야에 적용되는 유전가열 방식의 접촉형 가열기기의 공간적, 전기적 효율을 제고할 수 있는 한 방법을 제시한다.

Mechanical design of mounts for IGRINS focal plane array

  • Oh, Jae Sok;Park, Chan;Cha, Sang-Mok;Yuk, In-Soo;Park, Kwijong;Kim, Kang-Min;Chun, Moo-Young;Ko, Kyeongyeon;Oh, Heeyoung;Jeong, Ueejeong;Nah, Jakyuong;Lee, Hanshin;Pavel, Michael;Jaffe, Daniel T.
    • 천문학회보
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    • 제39권1호
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    • pp.53.2-53.2
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    • 2014
  • IGRINS, the Immersion GRating INfrared Spectrometer, is a near-infrared wide-band high-resolution spectrograph jointly developed by the Korea Astronomy and Space Science Institute and the University of Texas at Austin. IGRINS employs three HAWAII-2RG focal plane array (FPA) detectors. The mechanical mounts for these detectors serves a critical function in the overall instrument design: Optically, they permit the only positional compensation in the otherwise "build to print" design. Thermally, they permit setting and control of the detector operating temperature independently of the cryostat bench. We present the design and fabrication of the mechanical mount as a single module. The detector mount includes the array housing, a housing for the SIDECAR ASIC, a field flattener lens holder, and a support base. The detector and ASIC housing will be kept at 65 K and the support base at 130 K. G10 supports thermally isolate the detector and ASIC housing from the support base. The field flattening lens holder attaches directly to the FPA array housing and holds the lens with a six-point kinematic mount. Fine adjustment features permit changes in axial position and in yaw and pitch angles. We optimized the structural stability and thermal characteristics of the mount design using computer-aided 3D modeling and finite element analysis. Based on the computer simulation, the designed detector mount meets the optical and thermal requirements very well.

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