• The Transactions of the Korean Institute of Electrical Engineers D
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• v.52 no.1
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• pp.38-44
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• 2003

In this study, the balance beam control subsystem, new type of construction machinery using the mechanism of CMG (control moment gyro), for the attitude control of an unstructured object such as a beam carried by a tower crane, is designed and implemented. The balance beam controller consists of a wheel spinning at high speed and an outer gimbal for controlling the attitude of the wheel. Two motors, one for the wheel and the other for the gimbal, are used. Applying force to the spin axis of the wheel, as an input of the system, leads the torque about the axis because of the gyro effects. This torque is used to control the attitude of the unstructured object in this study. For the stabilizer function, in addition, holding the load at the current position, the attitude of the wheel is freed by cutting the power applied to the gimbal motor of the balance beam controller, which result in the braking force to stop the load by gyro effect. The works presented here include the mechanical system of the balance beam controller, the remote controller, the servo controller and the control software for the system. We also present experimental results to show that the system we proposed is useful as a new construction machinery which can control the attitude of the beam hanging from a tower crane.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.27 no.10
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• pp.935-940
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• 2016

Directed energy weapon enables to radiate the concentrated energy so as to result in distraction and overload of the target electronics. Analysis on effectiveness of weapon system can be important consideration in order to determine performance and design weapon system. In this paper, air defense weapon system, which is one of directed energy weapon system is studied. In order to analyze the effectiveness, the reflector antenna with high power circularly polarized horn antenna is designed, and power density in axial effective area is simulated and calculated using Friis formula. Through the study, the validity of antenna system is verified, and the effectiveness of directed energy weapon system on the target is evaluated.

• Journal of KIISE:Computing Practices and Letters
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• v.9 no.1
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• pp.95-99
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• 2003

In addition to wired communication technology, wireless communication technology has had communication revolution nowadays. Bluethooth technology carries out data/voice communication within pico-net. Nowadays the various services are supported by access network connected to public network. This paper presents implementation of bluetooth protocol analyser which simulates bluetooth protocol. MS window98 and visual C are used for development environment and application program is operated over the firmware loaded on the bluetooth device connected to the PC through UART which of the maximum transmission rate is 115kbps because transmission rate less than 20kbps affects rarely the performance. The performance analysis on the propose system is carried out as simulating the signalling information for the voice test and the traffics between two bluetooth systems for file transfer. The throughput analysis for file transfer service and call processing capacity for voice service are considered as performance analysis parameters. File access time is very important parameter and throughput is 13 kbps in case breakpoint time to file access is 0.04sec. Also call processing time is about 16.6ms in case of communication with the headset. The performance analysis of simulation results satisfies with bluetooth device development.

• Journal of dental hygiene science
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• v.4 no.1
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• pp.7-11
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• 2004

The purpose of this study was to investigate the distribution of microorganisms and the degree of contamination in the air of the dental clinics and to offer basic data as to the contamination of medical equipment and the prevention of the clinics. With this in mind, the researcher gathered air samples from the waiting rooms and medical offices of nine dental clinics in the city of J, South Korea with the use of a method of natural inattention and an air sampler and cultivated the samples on the plain table and drew from it bacteria falling and separated and sorted out the colony with the help of ATB and detected the distribution of the germs. The results are following, The number of bacteria falling in the air of the dental clinics was less than 10(CFU/Plate) with the exception of one dental clinic. This implies that they fit in with standards for hygiene. The number of bacteria falling in the air of the medical offices was less than 10(CFU/Plate) with the exception of one dental clinic. This implies that they fit in with standards for hygiene. The survey on the detection of staph. aureus reveals that all the dental clinics with the exception of B dental clinic proving to be positive had non-pathogenic staphylococci detected. The survey on the detection of pathogenic gram negative bacilli indicates that all the dental clinics but one were none detected. The survey on the distribution of germs shows that germs in 7 out of 9 dental clinics were none detected, and that they in four out of 9 waiting rooms were none detected. All the germs detected in the others were mostly non-pathogenic. The study shows that all the subject dental clinics but one were hygienically controlled and that there was a difference in accordance with cleaning and sterilization. This means that dental clinics should be equipped with systematic programs for cleaning and sterilization designed to prevent infection.

• Membrane Journal
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• v.24 no.4
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• pp.325-331
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• 2014

We synthesized novel polyimides with high gas permeability and selectivity for application of on board inert gas generation system (OBIGGS). 2,2-bis(3,4-carboxylphenyl) hexafluoropropane dianhydride (6FDA) and two kinds of amines with high permeability and solubility were used to prepare the novel polymide. 2,3,5,6-Tetramethyl-1,4-phenylenediamine (TMPD) was used to improve gas permeability and various kinds of diamines were used to improve the gas selectivity respectively. The polyimide copolymers were synthesized by commercial chemical imidization method and their average molecular weights were over 100,000g/mol. The glass temperature ($T_g$) and the thermal degradation temperature were characterized using differential scanning calorimeter (DSC) and thermogravimetric analysis (TGA). The synthesized copolymers showed high $T_g$ over $300^{\circ}C$ and high thermal degradation temperature over $500^{\circ}C$. The gas permeation properties were measured by time-lag equipment. Although general polyimides showed very low gas permeability, synthesized polyimide copolymer showed high $O_2$ permeability of 36.21 barrer with high $O_2/N_2$ selectivity around 4.1. From this result, we confirm that these membranes have possibility to apply to OBIGGS.

• The Journal of the Korea institute of electronic communication sciences
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• v.6 no.5
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• pp.673-681
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• 2011

Among the network information services combined with a number of security technologies and required security policies, Infrastructure as a Service, a hardware plat-form service of Cloud Computing, has been provided since 2011. It is more or less similar to the existing central concentration method services, in terms of the specifications and technical aspects for given hardware category, but it is entirely different from them in that it overcomes the spatial limitations of specific network and targets the public network. Information security technology has also been prospering so that it could ensure the stability of offered hardware plat-forms. As currently supported hardware, Internet Data Center has been provided by virtualizing the previously offered servers and discs (backup discs), but the hardware plat-forms offered are somewhat limited. Meanwhile, the areas of security fields for offered services are confined to the center or include the TCP/IP-based SSL (Secure Sockets Layer) for the public network connected with clients, which shows that microscopic access security policies have been used. Therefore, this study was aimed to provide a realistic security mechanism for realizing defense policy, by expanding service areas into security devices and suggesting Diskless and Stateless security policy based high-speed synchronous network infrastructure.

• Research in Plant Disease
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• v.24 no.3
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• pp.202-212
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• 2018

Major viruses infecting rice are transmitted by planthoppers such as small brown planthopper (SBPH), brown planthopper (BPH) and white-backed planthopper (WBPH). In this study, we investigated planthoppers captured during 2015 to 2017 by a smart sky net trap (SSNT) system installed in 40 areas in Korea, which is an automatic, rapid and real-time insect surveillance system. The average rates of captured migration plnathoppers was 27.5%, 17.2%, 15.3% and 10.9% in Chungcheongnamdo, Jeollanamdo, Jeollabukdo and Gyeonggido, orderly. The highly migrated month was July for SBPH, July to August for WBPH and August for BPH. To investigate the viruliferous rates of planthoppers of rice during 2015 to 2017, we performed RT-PCR using specific primers for each rice virus. RBSDV was detected from 0.4% in SBPH, while no viruses were detected in BPH and SBPH. Rice planthoppers exist all around in Asia. They can move long distance by wind from southern countries to Korea. Monitoring the migration of rice planthoppers and their viruliferous rates is important to prevent the outbreaks of rice virus diseases.

• Journal of KIISE:Computing Practices and Letters
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• v.5 no.6
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• pp.782-792
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• 1999

효과적인 ATM 망의 관리는 연결 지향 환경, 다양한 서비스 등급, 대규모 트래픽, 가상 망 구성 그리고 여러가지 트래픽 유형 등과 같은 다양한 ATM 특성을 다룰 수 있어야만 한다. 이를 위해 ATM 포럼에서는 ATM 장치, 사설망, 공중망 및 그들간의 상호작용을 지원하기 위한 ATM 망 관리 참조 모델을 정의하였으며, 그 중 하나가 서로 다른 판매자로부터의 ATM 장비들간의 상호동작성을 보장하기 위해 SNMP 기반 망 관리 프로토콜을 통해 상호 연결된 인터페이스를 관리할 수 있도록 정의된 통합 지역 관리 인터페이스(ILMI) 프로토콜이다. ILMI의 목적은 두 인접한 ATM 장치로 하여금 그들 간에 공통의 ATM 링크에 대한 동작 파라메타를 자동적으로 구성할 수 있도록 함으로서, 관리자에 의해 수동 구성이 아닌 ATM 장치 상호간의 플러그 앤 플러그 기능을 지원하는데 있다. 본 논문에서는 이러한 ILMI 기술을 바탕으로 공중망 ATM 교환기에 연결된 가입자의 물리 인터페이스, ATM 계층 인터페이스, VPC 및 VCC의 구성 및 상태 정보를 효율적으로 관리하며, 가입자 시스템의 ATM 주소를 자동으로 등록, 관리할 수 있도록 하는 가입자 인터페이스 관리 시스템(SIMS)을 설계하고, 구현하였다. Abstract An effective ATM management must address the various features of ATM such as connection-oriented environment, varying class of service, large scale traffic, virtual network configurations and, and multiple traffic types. For this, ATM network management reference model defined by ATM Forum describes the various types of network management needed to support ATM devices, private networks, public networks, and the interaction between them. One of these types is Integrated Local Management Interface (ILMI) defined to manage interconnected interface through SNMP-based network management protocol for ensuring the interoperability of ATM devices from different vendors. The purpose of ILMI is to enable two adjacent ATM devices to automatically configure the operation parameters of the common ATM link between them and then to provide a Plug and Plug function to any ATM devices with not a passive configuration by manager but a automatic configuration. This paper design and implement a Subscriber Interface Management System (SIMS) which provide automatic registration and management of ATM address of subscriber system and efficiently manages physical interface of subscriber who is connected to public ATM switch, ATM layer interface, configuration information and status information of VPC and VCC.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.3 no.2
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• pp.347-354
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• 1999

Generally, transceiver is operated to the remote control for the purpose of breading the traffic zone which is established on a mountain peak, island and building top using private line. Therefor, the remote control system of public radio station have been the very important role that is decision the quality relate to the quickness, accuracy, safety of communication on old type transceiver of SSB, VHF etc. In the case of using the only 1 private line which is exchanged voice signal with data signal had mixed or interrupted for up/down of channel, PTT control and monitoring of transmission channel and power. The up/down of channel and PTT control is according to the ASK and the data of monitoring is transfered to the FSK modulation, additional algorithm is studied on the serial protocol and traffic sequence using the MCS-51 processor in the simplex communication methode.

• 한국방재학회:학술대회논문집
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• 2011.02a
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• pp.71-71
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• 2011

캣워크는 현수교의 주케이블을 가설을 위해 일시적으로 설치하는 공중작업발판으로 주케이블 가설장비와 작업원 등의 하중을 지지한다. 캣워크는 유연한 구조물로서 풍하중에 상당한 변형이 발생한다. 하지만, 국내외를 막론하고 캣워크의 내풍안정성에 대한 연구는 별로 이루어지지 않았다. 거기에 더하여 캣워크에 작용하는 정적 공기력에 대한 정보도 부족하며, 현재 캣워크 단면에 대한 적절한 풍하중을 산정하지 못하고 경험적인 설계가 이루어지고 있다. 따라서 캣워크의 효율적인 내풍설계를 위하여 풍동실험을 통한 충실률과 공기력계수와의 관계를 알아보는 것이 필요하다. 이를 위하여 축척 1/4인 모형을 사용한 풍동실험을 통하여 메쉬망의 크기를 변화시키면서 충실률에 따른 공기력계수를 측정하고 설계식을 제안하고자 한다. 캣워크는 로프와 아울러 가는 철망으로 아래와 양 옆이 막혀 있다. 즉 바람을 직접 받는 부분인 철망은 가는 원형단면으로 구성되어 있다. 원형 단면의 경우에 레이놀즈 수에 따라 항력계수가 크게 변하는 것으로 알려져 있다. 그러나 가는 원형 단면으로 둘러싸인 캣워크의 항력계수에 레이놀즈 수가 미치는 영향에 대해서는 연구된 바가 없다. 본 연구에서는 캣워크의 공기력계수에 미치는 레이놀즈 수에 대한 영향을 파악하고자 1/4모형과 1/14모형을 제작하여 최대풍속 30m/s까지 변화시켜가면서 공기력계수를 측정하였다. 이때 레이놀즈 수는 최대 20배까지 차이가 나므로 만약 공기력계수가 레이놀즈 수의 영향을 받는다면 확실히 그 영향을 파악할 수 있다. 본 연구에서는 풍동실험을 통해 충실률과 공기력계수와의 관계과 레이놀즈 수의 영향을 살펴보았으며, 정적공기력 계수의 설계식을 제안하였다. 본 연구를 통하여 얻은 결과를 정리하면 다음과 같다. 1. 축척 1/14 및 1/4 모형을 사용하여 다양한 풍속에서 공기력계수를 측정한 결과, 캣워크에 작용하는 정적 공기력계수는 레이놀즈 수의 영향을 받지 않는 것으로 나타났다. 따라서 향후 새로운 형식의 캣워크에 대한 풍동실험을 수행할 경우에 축척에 상관없이 풍동실험 결과를 사용할 수 있을 것으로 판단된다. 2. 풍동실험 결과, 캣워크에 작용하는 정적 공기력계수 중 항력계수와 피칭모멘트계수는 측면 충실률에 따라 달라지고, 영각에 대한 양력계수의 기울기는 하부 충실률의 영향을 받는 것으로 나타났다. 그리고 주케이블이 캣워크 내부에 위치하고 있어도 캣워크의 정적 공기력계수에는 큰 영향을 미치지 않은 것으로 측정되었다. 이를 정리하여 캣워크 충실률에 따른 정적 공기력계수의 추정식을 제안하였다.