• 해양환경안전학회:학술대회논문집
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• 해양환경안전학회 2017년도 추계학술발표회
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• pp.138-138
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• 2017

• 시큐리티연구
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• 제4호
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• pp.65-82
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• 2001

Department of the imperial guard is of the soldiers organization which is formed in the royal power or the absolute near by a king. Thus, department of the imperial guard absolutely is showed it is a soldiers organization for guard a king. We summary the character and the function as followed when we subdivide. 1. The main mission was the guard of the royal palace. As we know from several historical materials, the defense of the royal palace was an fundamental mission. Therefore, department of the imperial guard would take charge of the defense of the royal palace. 2. They would carry out throne of king and the royal family or a battle. As unification, they would carry out guarding for political stability and a suppress probation of internal war in regard to the security and the frequent rebellion in central and locality. 3. They carried out guarding an honored going of a king or the royal family. We know the fact that there was an honored going of the royal family or many attendants on record. When a king or the royal family go, guarding of department of the imperial guard had not only protect them but also show off the authority of the royal family. As a result, when we analysis the substance from studying the guard system of Shilla, though our guard system is imitated the foreign guard system like U.S.A, transcending space-time, the guard system can be found a lot of something common at the guard principle and a rule. Today, in looking about a political system of any countries on the world, a king and a ruler of the country represent their country international, have responsibility of protect their nation and a people internal. Therefore, the guard for a ruler absolutely must carry out at a safety situation. Moreover the guard organ, at the same time is connected directly to a welfare of the nation, so we will have to devote a constant effort.

• 한국전기전자재료학회논문지
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• 제18권10호
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• pp.877-882
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• 2005

In order to fabricate a high breakdown SiC-SBD (Schottky barrier diode), we investigate an effect on metal guard ring (MGR) in breakdown characteristics of the SiC-SBD. The breakdown characteristics of MGR-type SiC-SBD is significantly dependent on both the guard ring metal and the alloying time of guard ring metal. The breakdown characteristics of MGR-type SiC-SBDs are essentially improved as the alloying time of guard ring metal is increased. The SiC-SBD without MGR shows less than 200 V breakdown voltage, while the SiC-SBD with Al MGR shows approximately 700 V breakdown voltage. The improvement in breakdown characteristics is attributed to the field edge termination effect by the MGR, which is similar to an implanted guard ring-type SiC-SBD. There are two breakdown origins in the MGR-type SiC-SBD. One is due to a crystal defects, such as micropipes and stacking faults, in the Epi-layers and the SiC substrate, and occurs at a lower electric field. The other is due to the destruction of guard ring metal, which occurs at a higher electric field. The demolition of guard ring metal is due to the electric field concentration at an edge of Schottky contact metal.

• 한국항공운항학회지
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• 제20권4호
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• pp.45-49
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• 2012

VDL(VHF Data Link) Mode E uses TDMA(Time Division Multiple Access) based aeronautical communication technologies for airborne environments. In the VDL Mode E, aircraft uses RR(Reservation Requests) slot to request data slot. However, RR needs a long guard time, since aircraft communication spans a considerable distance. The more number of aircrafts causes a larger amount of guard times which can make a throughput decreased. In this paper, we propose an enhanced MAC to reduce the guard time by using the distance information of aircraft. The ground station sends management data including time stamp. And then all aircraft can measure their distance from the ground station.

• Structural Engineering and Mechanics
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• 제12권5호
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• pp.541-558
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• 2001

The design specifications of guard fences in Japan were reexamined and the revised specifications were implemented from April 1999. Because of the huge consumption in time and cost to test the performances of full-scale guard fences in the field, some assumptions are adopted while modifying the design specifications, and numerical analyses are necessary to confirm the impact performance and safety level of new types of steel highway guard fences. In this study, the finite element models are developed for the heavy trucks and steel highway guard fences to reenact their behaviors, and the solution approach is carried out using nonlinear dynamic analysis software of structures in three dimensions (LS-DYNA). The numerical simulation results are compared with the full-scale on-site testing results to verify the proposed analysis procedure. The collision process is simulated and it is also made possible to visualize the movement of the truck and the performances of guard fences. In addition, the energy shift of the truck kinetic energy to the truck and guard fence Internal energy, and the energy absorption of each guard fence component are studied for the development of a new design methodology of steel highway guard fences based on the energy absorption capacity.

• 대한산업공학회지
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• 제25권3호
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• pp.351-359
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• 1999

We present a new approach to the analysis of mobile cellular communication systems under the environment of mixed platforms adopting a guard channel scheme. We assume general cell residence time distributions according to platform-types. Our system model is based on a heterogeneous M/G/c loss system with customer-dependent guard channels, where heterogeneous customers with different service time distributions have different numbers of their own guard channels. We develop the general formula of steady state probabilities for the heterogeneous M/G/c loss system with customer-dependent guard channels. The mean channel occupancy times of new and handoff calls are rigorously derived under a general setting. Finally, our numerical results show that the blocking probability and the forced termination probability are sensitive to the cell residence time distributions.

• 대한전자공학회논문지TC
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• 제37권2호
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• pp.24-31
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• 2000

무선 멀티미디어 망에서는 멀티미디어 트래픽의 변동성에 더하여 사용자의 이동성까지 고려하여야 하기 때문에 다양한 멀티미디어 트래픽을 위한 채널 할당 방식이 요구되어진다. 기존의 핸드오프 실패확률을 줄이기 위해 제안된 방식은 guard 채널을 이용한 방법으로 핸드오프 연결을 위하여 각각의 기지국에 guard 채널을 두는 것이다. 본 논문에서는 guard 채널을 사용한 무선 멀티미디어 망에서 핸드오프 연결에 우선권을 주는 효율적 채널 할당 방식을. 제안한다. 제안하는 방법은 guard 채널을 비실시간 연결과 실시간 핸드오프 연결이 공유하여 사용한다. 또한 핸드오프 실패 확률을 줄이기 위해서 망자원이 부족한 경우 진행중인 연결의 서비스 품질을 떨어뜨릴 수 있다. 시뮬레이션을 통하여 제안된 효율적인 채널 할당 방식이 기존에 제안된 방법들에 비해 채널 이용률과 핸드오프 실패확률에 대해서 우수한 성능을 가지고 있음을 보인다.

• 한국통신학회논문지
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• 제37C권11호
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• pp.1104-1111
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• 2012

공중 전술 네트워크는 공대공 또는 공대지 작전에 사용되고 전파 지연이 크다는 특징이 있다. 모든 노드는 TDMA 기반의 브로드캐스팅을 사용하여 데이터를 공유한다. 공중 전술 네트워크에서는 긴 전파 지연으로 인한 충돌 때문에, 브로드캐스팅을 보장하기 위해서는 각 타임 슬롯마다 보호 시간이 필요하다. 그러나 보호 시간의 낭비로 인해 네트워크의 채널 이용률이 크게 저하될 수 있다. 본 논문에서는 송신자 간 거리 정보를 사용하여 보호 시간의 낭비를 줄여 채널 이용률을 향상시키면서 브로드캐스팅을 보장하는 Inter-Transmitter Distance-Based TDMA (ID-TDMA) 기법을 제안한다. 그리고 성능 평가를 통해 ID-TDMA의 효과성을 확인하였다.

• 한국재난정보학회 논문집
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• 제6권2호
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• pp.11-20
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• 2010

All of the people or objects which are contacted during the activity of guard are added to range of objects. guard has to notice decision, question proposal, observation, accomplish to be happened them at the same time recognizing the steps as soon as possible. Before a lot of information of client are shown, guard expert has to search observation of materialization, extension of reservation, notification of business and causes of danger through personal interviews. Rapid communication system has to be assumed and effective caution, protection and shelter and following prevention are cooperated as well as has to care about safe of guard object by a protective wall. And also has to get out of the ground, keep the large shape when moves, prevent the trials of attack from the assassinators after takeing control over weapons.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2003년도 봄 학술발표논문집 Vol.30 No.1 (C)
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• pp.515-517
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• 2003

In this paper we examine the effects of the required portions of guard timing spaces in a MAC frame of ETSI BRAN HIPERLAN/2 system such as inter-mobile guard timing space in UL(Up Link) duration, inter-RCH(Random CHannel) guard timing space, sector switch guard timing space. In particular, we calculate the number of OFDM(Orthogonal Frequency Division Multiplexing) symbols required for these guard timing spaces in a MAC frame. We them evaluate the throughput of HIPERLAN/2 system as we vary parameter such as the guard time values defined in [2], the number of DLCCs(Data Link Control Connections), and the number of RCHs. Finally we show by numerical results that the portions for the 새심 summation of required guard timing spaces in a MAC frame are not negligible, and that they should be properly considered when trying to evaluate the performance of MAC protocol of HIPERLAN/2 system and also when determining the number of RCHs as well as the number of DLCCs in UL PDU trains at an AP/CC(Access Point/Central Controller).