• Clinical and Experimental Pediatrics
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• v.57 no.9
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• pp.379-383
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• 2014

Recombinant growth hormone (GH) is an effective treatment for short children who are born small for gestational age (SGA). Short children born SGA who fail to demonstrate catch-up growth by 2-4 years of age are candidates for GH treatment initiated to achieve catch-up growth to a normal height in early childhood, maintain a normal height gain throughout childhood, and achieve an adult height within the normal target range. GH treatment at a dose of $35-70{\mu}g/kg/day$ should be considered for those with very marked growth retardation, as these patients require rapid catch-up growth. Factors associated with response to GH treatment during the initial 2-3 years of therapy include age and height standard deviation scores at the start of therapy, midparental height, and GH dose. Adverse events due to GH treatment are no more common in the SGA population than in other conditions treated with GH. Early surveillance in growth clinics is strongly recommended for children born SGA who have not caught up. Although high dose of up to 0.067 mg/kg/day are relatively safe for short children with growth failure, clinicians need to remain aware of long-term mortality and morbidity after GH treatment.

• International Journal of Aeronautical and Space Sciences
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• v.11 no.4
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• pp.338-344
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• 2010

This paper discusses the development of the control system of a mini quadrotor in Konkuk University for indoor applications. The attitude control system consists of a stability augmentation system, which acts as the inner loop control, and a modern control approach based on modeling will be implemented as the outer loop. The inner loop control was experimentally satisfied by a proportional-derivative controller; this was used to support the flight test in order to validate the modeling. This paper introduces the mathematical model for the simulation and design of the optimal control on the outer loop control. To perform the experimental tests, basic electronic hardware was developed using simple configurations; a microcontroller used as the embedded controller, a low-cost 100 Hz inertial sensors used for the inertial sensing, infra-red sensors were employed for horizontal ranging, an ultrasonic sensor was used for ground ranging and a high performance propeller system built on an quadrotor airframe was also employed. The results acquired from this compilation of hardware produced an automatic hovering ability of the system with ground control system support for the monitoring and fail-safe system.

• Transactions of the Korean Society of Automotive Engineers
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• v.5 no.6
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• pp.155-166
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• 1997

In this study, a simulation tool is developed in order to investigate non steady-state cornering performance of 6WD/6WS special-purpose vehicles. 6WD vehicles are believed to have good performance on off-the-road maneuvering and to have fail-safe capabilities. But the cornering performances of 6WS vehicles are not well understood in the related literature. In this paper, 6WD/6WS vehicles are modeled as a 18 DOF system which includes non-linear vehicle dynamics, tire models, and kinematic effects. Then the vehicle model is constructed into a simulation tool using the MATLAB /SIMULINK so that input/output and vehicle parameters can be changed easily with the modulated approach. Cornering performance of the 6WS vehicle is analyzed for brake steering and pivoting, respectively. Simulation results show that cornering performance depends on the middle-wheel steering as well as front/rear wheel steering. In addition, a new 6WS control law is proposed in order to minimize the sideslip angle. Lane change simulation results demonstrate the advantage of 6WS vehicles with the proposed control law.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2011.11a
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• pp.277-281
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• 2011

장애학생들이 생활하는 특수학교의 경우 화재 발생빈도는 낮지만, 장애인은 초기 대응능력과 피난능력이 현저히 부족하므로 화재 발생 시 막대한 인명피해를 초래할 수 있다. 장애인의 안전한 피난을 위해서는 초기 소화설비와 피난에 필요한 경보설비, 피난설비의 설치 및 운영 그리고 피난보조자의 역할과 책임이 중요하기 때문에 특수학교를 대상으로 하여 소방시설의 설치 및 운영, 피난보조자의 화재안전의식에 대해 조사하였다. 그 결과 Fail-safe 원칙에 따라 2방향 이상의 피난이 가능해야 하지만 6개교 중 5개교가 평상시 안전을 이유로 비상구에 자물쇠를 채워 통행이 불가능하였고, 특수학교 교사들 중 피난시 교사들의 역할분담에 대해 54.2%가 모르고 있었으며, 피난보조자에 대해서도 64.5%가 모른다고 답하였다. 또한 소화기와 옥내소화전을 실제 사용해 본적 있는 교사는 각각 32.2%, 7.9%로 조사되어 화재발생시 초기소화를 담당해야 하는 교사들의 소화설비의 사용 경험이 부족한 것으로 나타났다.

• Journal of Aerospace System Engineering
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• v.8 no.2
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• pp.7-13
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• 2014

In order to enable fail-safe operation the electro-hydrostatic actuators can be dualized. When a symmetrical actuator is combined in series with an asymmetrical actuator with single rod cylinder, the flow rates of their cylinders are unmatched. If their position controller has same configuration, one of their pumps can supply too much flow rate under particular load conditions, which should be bypassed into low pressure side e.g. by a relief valve. In this paper it is shown how the hydraulic circuit for the asymmetrically combined electro-hydrostatic actuator can be designed without sacrificing power consumption.

• KIEAE Journal
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• v.9 no.5
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• pp.21-28
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• 2009

In apartment buildings, casualties, especially fatalities have occurred in balcony areas in fires if residents fail to escape to the main entrance. Potential consequences of a particular infrequent event should be considered. In attempting to design apartment buildings for fire safety, alternative escape methods such as vertical penetration could be considered. The purpose of this study is to investigate present building regulations regarding apartment buildings and examine pros and cons of the current escape method and alternative escape methods. Focus group interview was conducted to discuss problems of fire escape methods. In addition, questionnaires were distributed to field professionals working in architecture, construction and related industries. Among 500 questionnaires distributed, 192 questionnaires were collected. Usable 162 questionnaires were analyzed using SPSS 15. Regarding alternative fire escape methods, several concerns were mentioned. Safety, privacy, security, effectiveness of escape, water proof problems were raised. Based on the opinions, vertical penetration between apartment unit appeared more safe, secure, effective than horizontal penetration. However, both methods have its own pros and cons under specific contexts. Alternative escape methods need be considered for a selective options for residents in case of fire.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.13 no.4
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• pp.44-49
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• 2014

Roll forming technology has a problem in that it depends only on experience without accurate data in the actual field. To solve this problem, it is necessary to procure accurate data during the roll forming process. To this end, we determined the operating force and the material thickness by implementing several changes to those variables during an experiment. This study compares the FEA results and experimental results. Experimental results were used for the basic data of the design. The FEA results show that the roll forming machine is operating accurately and safely. And, a comparison of the results shows that the design of the automatic roll forming machine is operating in the right way. This design of an automatic roll forming machine will be helpful for many areas of the industry.

• Journal of the Korea Society of Computer and Information
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• v.23 no.10
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• pp.157-164
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• 2018

The purpose of this study was to investigate the effect of empowerment in nurses through a systematic literature review and meta-analysis. 23 studies were collected through a systematic process of using several databases such as NDSL, DBPIA, and KISS. Keywords included 'nurse', 'empowerment', and 'correlation' and the reviewed articles were published from 2002 to 2017. In order to estimate the effect size of correlation between empowerment, 3 variables (job satisfaction, organizational commitment, and nursing performance) were considered. Using the R program, meta-analysis was calculated by using random effects model, and effect sizes on three types were estimated. As the result, it was found, first, the effect size of correlation between job satisfaction and empowerment is .50. Second, the effect size of correlation between organizational commitment and empowerment is .45. Third, for the nursing performance and empowerment relationship, the effect of correlation is 0.50. Also, Egger's regression test, fail-safe N, trim-and-fill test, and funnel plot were showed to evaluate the results. These results highlights the need for appropriate policies of the relationship between empowerment and job satisfaction, organizational commitment and nursing performance in nurses.

• Proceedings of the KSR Conference
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• 2003.05a
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• pp.456-461
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• 2003

기존선 속도 향상 및 병목현상 해소와 안전운행을 위해 국내 철도 현황의 주요 분야를 검토한 후, 국내 17년동안 사용으로 안전성이 검증된 신호기술을 바탕으로 국내 실정에 적합하며, 기존의 ATS 장치를 개선한 정보형 ATS(ATPS)를 개발하여 이를 제시하였다. 본 시스템은 운행 중인 열차의 제동특성을 고려하여 구간별 제한속도를 상향 조정하여 운행 효율을 증가 시킬 수 있다. 또, 안전성과 신뢰성 보장을 위해 Fail-Safe 및 이중계(redundancy)로 제작 하였고, 기존의 차상자와 발진기를 통합함으로써 Q factor를 개선하여 무응동 방지 및 기준 응동시간 비교방식을 통해 오동작을 개선하였다. 그리고, 정보기록 장치를 추가함으로써 이미 기록되어있는 차량정보데이터와 지상정보데이터를 연산하여 운전정보를 제공하고 기록한다. 또한, 이 운전정보는 정보 분석용 PC 및 프로그램에 의해 쉽게 분석, 관리가 가능하다. 무엇보다도 기존 ATS 구간과의 겸용사용으로 영업 운전시 안전한 연속 운행 보장 및 지상설비 개량 없이 안전을 확보할 수 있다. 다양한 종류의 동력차에 설치, 인터페이스 및 지상설비 개량이 용이하다. 향후 틸팅 시스템과 연계하여 틸팅 제어/감시 신호를 제공하는 기능을 갖는다.

• Journal of the Korea Safety Management & Science
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• v.13 no.3
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• pp.1-8
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• 2011

The overall goal of a safety based railroad system is either to eliminate hazards in designing or to minimize the possibility of it. In order to indicate system safety or low risk although it may not be possible to achieve zero risk conditions, first, it shall ensure that any disasters would occur due to system operation because the prescribed specifications are properly fulfilled and there are no failures of any kind. Second, the risk of faults or failures leading to a mishap must be eliminated or minimized by using fault-tolerance or fail-safe procedures. This paper will attempt to summarize the personal and social risk criterion at widely scattered points, presently used as a safety approach in all over EU, in order to establish the step by step procedures of the detailed standard for railway facilities. In addition, we present the new safety analysis method using the SIL-based evaluation standard and the Reachability Graph of the Petri Net.