• Title/Summary/Keyword: Attitude Control System

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A Study on the Steady-State Characteristics of Symmetric Pintle Nozzle with Varying Position of Pintle and Change in Altitude (대칭형 핀틀 노즐의 핀틀 위치와 고도 변화에 대한 정상상태 특성 연구)

  • Jeong, Kiyeon;Kang, Dong-Gi;Jung, Eunhee;Lee, Daeyeon;Choi, JaeSung
    • Journal of the Korean Society of Propulsion Engineers
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    • v.23 no.1
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    • pp.33-45
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    • 2019
  • In this study, numerical simulations were performed to investigate the steady-state characteristics of a symmetric pintle nozzle by varying the position of the pintle and the altitude. The pintle nozzle shape was used in a linear pintle nozzle that had been analyzed prior to the study, and the boundary conditions of the chamber were considered to be according to the propellant burn-back characteristics. A software was used to perform a verification analysis of the square nozzle, pintle nozzle, and high-altitude conditions with an appropriate analytical technique. The pintle position had three different nozzle throat area conditions-: fully closed, half open, and fully open, and the altitude was set at 0, 5, and 20 km. The study compared the thrust, pintle drive load, and static stability at each condition.

A Study on Importance and Satisfaction of Students about Forest Healing Instructor Training Program Using ISA Analysis (ISA 분석을 이용한 산림치유지도사 양성과정에 대한 수강생의 중요도와 만족도 연구)

  • Kim, Soyeon;Kim, Mina;Kim, Gyuri;Choi, Jungkee
    • Journal of Korean Society of Forest Science
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    • v.108 no.1
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    • pp.109-115
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    • 2019
  • The objectives of this study was to analyze the importance and satisfaction (ISA) of forest healing instructor training program, targeting on the students educated in 2018. As a result, it was found that students older than forties are the majority as 81 %, and they preferred forest healing instructors as their second future job. When comparing the importance and satisfaction, the students evaluated satisfaction with low grade compared to importance with high grade in all questions. In ISA analysis, it was needed to improve the updated textbook information, to list the example problems by subject, to expose the test subjects in the textbooks, to disclose the test questions and answers, to control the test difficulty, to adjust the test pass rate, to expand the number of test and test sites, to increase the effort for making students understand, to prepare lectures appropriate to practice for forest healing instructor training program by priority.

A Study on Status of Utilization and The Related Factors of Primary Medical Care in a Rural Area (일부 농촌지역의 일차의료이용실태와 그 관련요인에 관한 연구)

  • Wie, Cha-Hyung
    • Journal of agricultural medicine and community health
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    • v.20 no.2
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    • pp.157-168
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    • 1995
  • This study was carried out, through analyzing the annual reports(year of 1973-1993) on health status of Su Dong-Myun, and specific survey data of 332 households(Su Dong-Myun 209, Byul Nae-Myun 123), located in Nam Yang Ju-Si, Kyung Gi-Do, from July 20 to July 31, 1995, to find out more effective means for primary medical care in a rural area. The results were as fellows : 1. Number of population in Su Dong-Myun was 5,419 in 1973, 4,591(the lowest) in 1987 and 5,707 in 1995. In the composition rate of population, "0-14" of age group showed markedly decreasing tendency from 43.1% in 1975, to 19.1% in 1995, however "65 and over" markedly in creasing tendency form 5.3% in 1975 to 9.8% in 1995. 2. Annual utilization rate per 1,000 inhabitants in Su Dong-Myun showed markedly increasing tendency from 1973 to 1977 such as 343 in 1973, 540 in 1975, 900 in 1977. However, since 1979, the rate showed rapidly decreasing tendency, such as 846 in 1979, 519 in 1985, 190 in 1991 and 1993. 3. The morbid household rate per year was 53.6% of respondents and the rate per 15 days was 48.2%. In disease classification rate of morbid household per year, Arthralgia & Neuralgia was the highest rate(33.9%) and gastro-intestinal disorder(19.3%), Cough(11,9%), Hypertension(7.8%), Accident(3.2%) in next order. 4. In the utilizing facilities for Primary Medical Care, Medical facilities was showed the highest rate(58.1% of respondents) and Pharmacy and Drug Shp(33.1%), Tradition Method(4.0%) in next order. In the Medical facilities, General private clinic was showed the highest rate(34.3%) and specific private Clinic(22.3%), Hospital(19.0%), Health (Sub)center(16.3%), Nurse practitioner (3.3%), Oriental hospital and clinic(2.7%) in next order. 5. Experience rate, utilizing health subcenter was 51.8% of the respondents, and it was 55.0% in Su Dong-Myun and 46.3% in Byul Nae-Myun. In utilization times of health subcenter, times-rate showed next orders such as 1-2 times/6months(31.6%), 1-2 times/year (22.1%), 1-2 times/months(19.2%), 1-2 times/3months(15.6%). 6. In objectives, visiting Health Subcenter, Medical Care was the highest rate(59.8% of the respondents) and health control(23.3%) was in next order. In Medical Care, Primary Care by general physician was higher rate(51.1%) almost all. In the Health control, Immunization too was high rate(18.0%) in health control activities. 7. The reasons rate, utilizing health subcenter showed next order, such as distance to Medical facilities(33.0% of the respondents), Medical Cost(28.1%), Simple process of consultation (10.8%), Effectiveness of cure(7.6%), Function of primary medical care(7.0%) and Attitude of physician(6.5%). 8. In the affecting factors to utilization of primary medical facilities, medical needs was showed the highest rate(29.5% of the respondents) and medical cost(15.4%), distance to medical facilities(14.2%), traffic vehicle(14.2%) and farm work(6.9%) in next order. 9. In the priority between 'daily farm work,' and 'primary medical care', only 46.4% of respondents answered that primary health care is more important than the daily farm work The 22.6% of respondents answered 'daily farm work', and the 12.3% answered 'the equal of the both'. 10. In the criterion of medical facilities choice, medical knowledge and technical quality was showed the highest rate(56.3%), distance or time to medical facilities(10.9%), sincerity and kindness of physician(9.4%), medical cost(8.7%) and traffic vehicle(6.5%) in next order 11. In the advise for improvement of health subcenter function, the 36.1% of respondents answered that 'enforcement of medical personnel and equipment' was required, and then 'improved medical technology'(25.5%), 'good attitude of physician'(14.9%), 'improved medical system'(13.3%), 'enforced drug'(6.7%) in next order. 12. The study on affecting factors to utilization of primary medical facilities was very difficult subject to systematize the analyzed results, due to a prejudice of protocol planner, surveyer and respondent, and variety and overlapping of subject matter.

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A Study on Participation Intention and Herd Behavior on Domestic Securities Type Crowdfunding Investors: Focusing on the Theory of Planned Behavior (국내 증권형 크라우드펀딩 투자자의 참여의도와 무리행동에 관한 연구: 계획된 행동이론을 중심으로)

  • Hwang, Nakjin;Lee, So-young
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.15 no.2
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    • pp.1-18
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    • 2020
  • This study is to identify the influence of major variables that affect the participation intention of securities type crowdfunding investors and how participation intention and perceived behavioral control affect investors' herd behavior including indirect effect analysis based on the theory of planned behavior. The ultimate purpose of this study is to understand the investment behavior of securities type crowdfunding investors and to help the relevant parties to develop various policies and business plans to revitalize the system and protect investors. An online survey was conducted on people who are interested or have experience in securities type crowdfunding to receive a total of 276 responses. Excluding outliers, a total of 261 responses were taken into account for the final analysis. For the data analysis, structural equation model analysis using SPSS 22.0 and Amos 22.0 statistical package was conducted. As a result, two of the major variables of the theory of planned behavior-attitude and subjective norm-have been found to have a positive effect on the participation intention of securities type crowdfunding investors. And after analyzing the indirect effect, the participation intention was found to play a mediating role between attitude, subjective norm and herd behavior. However, the perceived behavioral control presented as a major variable of behavioral intention in the theory of planned behavior showed that the effect on participation intention was statistically insignificant. Instead, it was found to have a direct positive effect on herd behavior. This is significant because it empirically confirmed that even if investors perceive securities type crowdfunding as easy to participate, perceived behavioral control does not seem to have a significant impact on participation intention because securities type crowdfunding is an investment in an early-stage business with a high risk of loss. On the other hand, the study has great significance in that it empirically confirmed that domestic securities type crowdfunding investors perceive the funding progress information provided by the platform as a signal and imitate many other investors, showing herd behavior when they actually make an investment. It is expected that this study will provide meaningful insights for the policy making of crowdfunding supervisory offices and platform operators by empirically identifying major variables that influence the participation intentions and herd behavior of domestic securities type crowdfunding investors.

Research libraries as a scholarly communication system (학술정보 커뮤니케이션 시스팀으로서의 연구도서관)

  • 이영자
    • Journal of Korean Library and Information Science Society
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    • v.9
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    • pp.179-211
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    • 1982
  • Many problems which today's research libraries are confronted with should be taken the measures to find some solutions in any ways. The purpose of this study is to identify the main stream of chaining of research libraries as an existing collector and distributor of scholarly information into a communication system adopting the concept of resource sharing and on-line bibliographic search as some possible ways for solutions. The conclusions of this study can be summarized as follows: 1) The research libraries will be imposed on more and more responsibilities to be a reservoir of the intellectual heritage of an individual, a nation and mankind. 2) The research libraries in the near future will have to develop their collections in the new environment of austerity with the limited budget. 3) It is more desirable for the future research libraries to have the attitude that they are in the business of information and communication rather than being an entity as "a library". 4) The resource sharing developed to solve the severe problems confrontal by research libraries will improve the organizational and technical mechanism for the access to the scholarly information. 5) The research libraries will produce more and more bibliographic database to expand the library materials which can be available and shared. 6) Though on-line search service will be sure to provide a considerable profit to the scholarly information users, it will take a long time for this service to be popularize because of the high ratio of service fee. 7) Two problems should be solved for the efficient service by on-line search. One is the continuous, updating training for the professional librarians. The other is that the common efforts for the quality control and standardization of data base by the data base producers should be made. 8) Taking all the items of the conclusions derived from the study of research libraries mainly in the United States into a consideration, the followings should be paid an attention. - The status-quo of the research libraries in Korea should be analyzed in very detailed and accurate way. - The problems of research libraries in Korea as the major scholarly communication system should be clarified based on the analysis. - The measures for the problems should be taken in the light of the unique characteristics of korean environment. - For the developing the most efficient measures, the formal organize action to lead and govern the long-aimed study on the problems of research libraries should be established and the government-level su n.0, pport for the legislation and finance should be provided for the realization of the result of the study.

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System Development of Cubsat SIGMA(KHUSAT-3)

  • Shin, Jehyuck;Lee, Seongwhan;Lee, Jung-Kyu;Lee, Hyojeong;Lee, Jeongho;Seo, Junwon;Shin, Youra;Jeong, Seonyeong;Cheon, Junghoon;Kim, Hanjun;Lim, Jeonghyun;Lee, Junmin;Jin, Ho;Nam, Uk-Won;Kim, Sunghwan;Lee, Regina;Kim, Hyomin;Lessard, Marc R.
    • The Bulletin of The Korean Astronomical Society
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    • v.39 no.2
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    • pp.106-106
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    • 2014
  • SIGMA (Scientific cubesat with Instrument for Global Magnetic field and rAdiation)는 근 지구공간에서 우주방사선량 측정과 자기장 변화 검출의 과학적 목적과 교육적 목적을 가지고 개발하고 있는 초소형 큐브위성이다. $100mm{\times}100mm{\times}340.5mm$의 크기로 약 3.6 kg의 무게를 가지며, 탑재체는 방사선에 대하여 인체와 동일한 산란 흡수 특성을 가진 Tissue Equivalent Proportional Counter (TEPC)와 자기장 측정을 위한 Magnetometer (Mag)이다. 위성체는 구조계, 자세제어계, 전력계, 명령 및 데이터처리계, 통신계로 구성되어있다. 구조계는 위성의 뼈대인 Chassis와 Mag deployer로 이루어져있고, 위성의 안정적인 자세유지를 목적으로 Attitude Control System (ACS) Board와 Torque Coil이 자세제어계로 구성된다. 전력의 생산과 공급 및 충전은 태양전지판과 Electrical Power System (EPS), 리튬 배터리로 구성된 전력계에서 이뤄지며, 명령 및 데이터처리계는 On Board Computer (OBC)와 Instrument Interface board (IIB)를 중심으로 서브시스템의 명령체계와 데이터처리를 다룬다. 통신계는 Uplink인 VHF 안테나와 Downlink인 UHF, S-band 안테나로 구성되며 지상과 명령을 송수신한다. SIGMA는 타임인터럽트 기능을 활용한 Flight Software (FSW)로 운용되며 임무에 따른 6가지 모드의 시나리오로 위성을 운용한다. 이에 SIGMA의 개발과 테스트 결과를 소개한다. 본 큐브위성 개발기술을 바탕으로 향후 천문관측용 위성에도 활용할 예정이다.

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Development of the Balance Chair for Improving Postural Control Ability & Pelvic Correction (골반교정 및 자세균형능력 증진을 위한 균형의자 개발)

  • Oh, Seung-Yong;Shin, Sun-Hye;Kang, Seung-Rok;Hong, Chul-Un;Kwon, Tae-Kyu
    • Journal of rehabilitation welfare engineering & assistive technology
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    • v.11 no.3
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    • pp.271-277
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    • 2017
  • The purpose of this study was to develop a balance chair for improving pelvic correction and postural balance through postural balance training using tactile feedback by a vibration motor provided in real time according to the user's attitude. We built a body frame using mono cast(MC) Nylon, Touch thin film transistor(TFT) for user interface, a main control module using Arduino, a 9-axis acceleration sensor for user's posture determination, and a vibration module for tactile feedback. The prototype of the Balance Chair which surrounds the outside was made with cushion for sitting conformability. In order to verify the effectiveness of the postural balance training system using the built prototype, the muscle activity (% MVIC) of the left and right iliocostalis lumborum those are the main muscles of the spinal movement was measured with ten female subjects. And the balance ability before and after training was measured using Spine Balance 3D, a posture balance ability evaluation device. The muscular activities of the left and right iliocostalis lumborum showed the balance activation according to vibration feedback during exercise protocol and postural balance improved after balance exercise training using balance chair. This study could be apply to use the fundamental research for developing the various postural balance product.

Enterprise Human Resource Management using Hybrid Recognition Technique (하이브리드 인식 기술을 이용한 전사적 인적자원관리)

  • Han, Jung-Soo;Lee, Jeong-Heon;Kim, Gui-Jung
    • Journal of Digital Convergence
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    • v.10 no.10
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    • pp.333-338
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    • 2012
  • Human resource management is bringing the various changes with the IT technology. In particular, if HRM is non-scientific method such as group management, physical plant, working hours constraints, personal contacts, etc, the current enterprise human resources management(e-HRM) appeared in the individual dimension management, virtual workspace (for example: smart work center, home work, etc.), working time flexibility and elasticity, computer-based statistical data and the scientific method of analysis and management has been a big difference in the sense. Therefore, depending on changes in the environment, companies have introduced a variety of techniques as RFID card, fingerprint time & attendance systems in order to build more efficient and strategic human resource management system. In this paper, time and attendance, access control management system was developed using multi camera for 2D and 3D face recognition technology-based for efficient enterprise human resource management. We had an issue with existing 2D-style face-recognition technology for lighting and the attitude, and got more than 90% recognition rate against the poor readability. In addition, 3D face recognition has computational complexities, so we could improve hybrid video recognition and the speed using 3D and 2D in parallel.

BORDERLINE DISORDER OF CHILDHOOD : 8 CASES (아동기 경계선 장애 : 8증례)

  • Hong, Kang-E;Lee, Jeong-Seop;Shin, Min-Sup
    • Journal of the Korean Academy of Child and Adolescent Psychiatry
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    • v.6 no.1
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    • pp.3-17
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    • 1995
  • The so-called borderline children are characterised by disturbances in the sense of reality and interpersonal relationships, lack of control, fluctuation of functioning, uneven development and excessive anxiety. But the concept of borderline disorder of childhood is very difficult to define and diagnose in current classification system. The present study adapted the consensus symptoms in borderline children by Bemporad and Vera eight cases aged 7-11 were examined in 37 variables. Results are as follows 1) All subjects are boys and girl hardly be diagnosis n current diagnostic system and have many concurrent diagnoses. Common chief complaints in the sense of reality. 2) In KEDI-WISC test, the borderline children showed average intelligence, but performance IQ tends to be higher than verbal IQ. In Rorscharch test, they showed high thought disorder index, emotional instabilities and aggressive impulses. The results of TOVA suggested attentional deficit in half of the subjects. The organicity is not prominent. 3) Many of the borderline children were unwanted baby. Although primary care takers of all the subjects were their mothers there were moderate problems in caring attitude of their children and marital relationship with their husband. Sccioeconomic status was generally below middle class. Most of all subjects have delayed language development, but have overcome subsequently. Many subjects were rejected by peers because of their aggression. 4) The first visit of the subjects was about 6 years of age. Average duration of treatment was 2 years. All of them were treated in the outpatient basis except one. The effect of pharmacotherapy was doubtful and the necessity of long term play therapy was suggested. Although there were many limitations of method in present study, it was suggested that further research is needed for diagnostic criteria, epidemiology and treatment.

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Simulation of Sensor Measurements for Location Estimation of an Underwater Vehicle (수중 운반체 위치 추정 센서의 측정 시뮬레이션)

  • Han, Jun Hee;Ko, Nak Yong;Choi, Hyun Taek;Lee, Chong Moo
    • Journal of the Korean Institute of Intelligent Systems
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    • v.26 no.3
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    • pp.208-217
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    • 2016
  • This paper describes a simulation method to generate sensor measurements for location estimation of an underwater robot. Field trial of a navigation method of an underwater robot takes much time and expenses and it is difficult to change the environment of the field trial as desired to test the method in various situations. Therefore, test and verification of a navigation method through simulation is inevitable for underwater environment. This paper proposes a method to generate sensor measurements of range, depth, velocity, and attitude taking the uncertainties of measurements into account through simulation. The uncertainties are Gaussian noise, outlier, and correlation between the measurement noise. Also, the method implements uncertainty in sampling time of measurements. The method is tested and verified by comparing the uncertainty parameters calculated statistically from the generated measurements with the designed uncertainty parameters. The practical feasibility of the measurement data is shown by applying the measurement data for location estimation of an underwater robot.