• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1999년도 하계학술대회 논문집 C
• /
• pp.1347-1350
• /
• 1999

접지는 최근까지 대형 변전소를 제외한 대부분의 분야에서 정확한 현장 분석 없이 단순히 접지저항만을 계산하여 시공하고 있다. 본 논문에서는 접지 설계에 필수적인 시공 현장의 대지저항률을 실측하여 컴퓨터 시뮬레이션을 통해 지질특성을 분석한 후, 3가지 방식의 접지시스템을 현장에 맞게 설계 시공하였다. 각각의 접지 시스템의 시공은 동일한 장소에서 이루어 졌으며, 시공된 각각의 접지시스템들의 결과를 실측하여 접지 설계에 따른 시공 성능을 확인하였으며, 접지시스템들의 성능과 특성을 상호 비교 분석함으로써 현장에 가장 적합한 접지시스템을 제안하였다.

• The Korean Journal of Pain
• /
• 제7권2호
• /
• pp.181-187
• /
• 1994

The MAC($ED_{50}$)values of enflurane, fentanyl, and nalbuphine-enflurane under 65% $N_2O$ were determined in 76 Sprague-Dawley rats using the tail-clamp technique to compare the equipotent effects of intravenous and inhaled anesthetics. The rats were divided into 3 groups: enfluarne, fentanyl, and nalbuphine-enflurane. Results were as follows: 1) The MAC value of enflurane under 65% $N_2O$ was $1.160{\pm}0.05%$ and after subcutaneous nalbuphine 20 mg/kg injection, the values were 1.08% at 60min and 0.99% at 90min. 2) The lowest $ED_{50}$ for fentanyl was 26.8 ${\mu}g$/kg at 15 min, and the $ED_{50}$, 30, 45, and 60min after the injection were 36.2, 39.7, and 44.7 ${\mu}g$/kg, respectively. 3) On arterial blood gas analysis under 65% $N_2O$-1MAC($ED_{50}$), fentanyl and nalbuphine-enflurane groups showed mild increase in $PaCO_2$, but there were no significant differences among 3 groups. Fentanyl group showed significant difference in pH compared with enfluarane and nalbuphine-enflurane groups. 4) Rats injected with high dose fentanyl(above $40{\mu}g$) displayed rigidity and respiratory depression.

• 한국정보과학회:학술대회논문집
• /
• 한국정보과학회 2011년도 한국컴퓨터종합학술대회논문집 Vol.38 No.1(D)
• /
• pp.325-327
• /
• 2011

With increasing competition of the radio spectrum, co-channel interference(CCI) is becoming the dominant interference and may seriously degrade the communication performance of wireless stations. Co-channel interference, when not minimized, increases the probability of packet collisions which cause diminished system capacity. The work presented in this paper investigates the effect of co-channel interference, which is studied in a co-channel interference scenario. To minimize the co-channel interference, a new MAC protocol is proposed in this paper.

• 한국정보과학회:학술대회논문집
• /
• 한국정보과학회 2007년도 가을 학술발표논문집 Vol.34 No.2 (D)
• /
• pp.602-607
• /
• 2007

최근 4G 이동통신 시스템의 진화를 위한 단계로 기존의 이동통신 시스템을 유지하면서 효율 극대화를 통한 비용 절약 측면과 고 주파수 대역을 이용한 셀 간격의 협소화로 인해 나타나는 문제점에 대한 대안으로 커버리지 확대와 데이터 처리율 향상을 위한 IEEE 802.16j 표준화 작업이 진행 중에 있다. 향후 VoIP 서비스를 위한 업링크 스케줄링 기법으로 몇 가지가 IEEE 802.16j에 제시되어 있으나, 본 논문에서는 보이스 트래픽 특성 및 수학적 모델링을 통하여 기존 방법들보다 더 효율적인 대역 이용을 통해 같은 대역폭 대비 성능과 용량 면에서 개선된 스케줄링 기법인 eertPS를 제시하여 IEEE 802.16j Multi-Hop 환경하에서도 대역 효율적인 VoIP 서비스를 이용할 수 있도록 한다.

• 한국정보과학회:학술대회논문집
• /
• 한국정보과학회 2008년도 한국컴퓨터종합학술대회논문집 Vol.35 No.1 (D)
• /
• pp.131-136
• /
• 2008

와이브로는 IEEE 802.16e 기반으로 이동 중에도 사용자에게 고속 무선 데이터 서비스를 제공하는 기술로 IPv4 기반 인터넷을 통한 이동성 지원은 원활하게 제공되나 IPv6 환경에서는 많은 문제점을 가지고 있다. 와이브로 MAC은 유선망의 이더넷과 와이브로 망 구성요소 간 점대다 연결과 브로드 캐스트 기능을 지원하지 않는다. 또한 이더넷에서 사용하는 MAC 주소를 대체한 CID(Connection ID)를 사용하기 때문에 Mobile IPv6에서 CoA(Care of Address) 생성을 위한 IPv6 Address Auto-Configuration 기능을 이용하는 것은 매우 어렵다. 본 논문에서는 와이브로 서비스 제공을 위하여 Mobile IPv6의 Proxy 기능을 도입하고 이를 적용하는 방안을 제시한다. 제안된 방식을 통하여 와이브로 망에서 IPv6의 장점을 이용한 고속 핸드오버 서비스 제공이 가능하다.

• Journal of Mechanical Science and Technology
• /
• 제19권11호
• /
• pp.2061-2067
• /
• 2005

In this study, we focus on the submerged plate built into the Very Large Floating Structure with the partial openings of Sm long, which enables the reverse flow of incident wave to generate the wave breaking. The purpose of this study is to investigate the characteristics of wave exciting forces acting on the submerged plate and the fore part of VLFS. Firstly, we have carried out the extensive experiments to understand the characteristics of the wave exciting forces. Then we have performed the numerical simulations by applying the Marker and Cell method (MAC method) and compared with the experimental results. We discuss the validity of MAC method and the effects of the submerged plate on the motion of VLFS. As a result, we get the conclusion that the submerged plate is useful for reducing the wave exciting forces acting on the structure behind the submerged plate.

• Journal of Veterinary Science
• /
• 제23권4호
• /
• pp.53.1-53.9
• /
• 2022

Background: Problems associated with using inhalational anaesthesia are numerous in veterinary anaesthesia practice. Decreasing the amount of used inhalational anaesthetic agents and minimising of cardiorespiratory disorders are the standard goals of anaesthetists. Objective: This experimental study was carried out to investigate the sparing effect of intravenous tramadol, lidocaine, dexmedetomidine and their combinations on the minimum alveolar concentration (MAC) of sevoflurane in healthy Beagle dogs. Methods: This study was conducted on six beagle dogs. Sevoflurane MAC was determined by the tail clamp method on five separate occasions. The dogs received no treatment (control; CONT), tramadol (TRM: 1.5 mg kg^-1 intravenously followed by 1.3 mg kg^-1 h^-1), lidocaine (LID: 2 mg kg^-1 intravenously followed by 3 mg kg^-1 h^-1), dexmedetomidine (DEX: 2 ㎍ kg^-1 intravenously followed by 2 ㎍ kg^-1 h^-1), and their combination (COMB), respectively. Cardiorespiratory variables were recorded every five minutes and immediately before the application of a noxious stimulus. Results: The COMB treatment had the greatest sevoflurane MAC-sparing effect (67.4 ± 13.9%) compared with the other treatments (5.1 ± 25.3, 12.7 ± 14.3, and 40.3 ± 15.1% for TRM, LID, and DEX treatment, respectively). The cardiopulmonary variables remained within the clinically acceptable range following COMB treatment, although the mean arterial pressure was higher and accompanied by bradycardia. Conclusions: Tramadol-lidocaine-dexmedetomidine co-infusion produced a remarkable sevoflurane MAC-sparing effect in clinically healthy beagle dogs and could result in the alleviation of cardiorespiratory depression caused by sevoflurane. Cardiorespiratory variables should be monitored carefully to avoid undesirable side effects induced by dexmedetomidine.

• 전기학회논문지
• /
• 제59권7호
• /
• pp.1302-1308
• /
• 2010

In this study, Zigbee Sensor Node to transmit harmful gases CO and $CO_2$ information using wireless communication within the ground and underground structures were developed. Wireless communication protocol was used Zigbee Stack included IEEE 802. 15.4 MAC protocol. For wireless transmission of detected harmful gas signal from ADC of MCU was implemented Zigbee Sensor Node that was developed protocol using Serial-Port-Profile(SPP) here. The proposed Zigbee Sensor Node was verified transmission distance from experiments. Transmission distance was into 90m in experiments. Distance experiments were measured at 10m intervals using sine & pulse wave input signal at indoors. The proposed Route Sensor Node was applied mesh routing protocol. When built up USN(Ubiquitous Sensor Network)using Route Sensor Node, transmission distance was not limited. On the experimental results, harmful gas values between direct measurements and USN measurements were consistent. The semiconductor CO sensor and N-DIR $CO_2$ sensor module as a harmful sensor was used. Therefore, the proposed Zigbee Sensor Node was verified about reliability and validity to build USN for transmission of harmful gas information.

• 한국산업융합학회 논문집
• /
• 제20권4호
• /
• pp.299-305
• /
• 2017

This study proposes a new technique to design and control of robot hand gripper for assembling and disassembling of a machine parts. The motion equation describing dynamics of the manipulators and object together with geometric constraint is formulated by Lagrange-Euler's equation. And the problems of controlling both the grasping force and the rotation angle of the grasped object under the constraints are analyzed. The effect of geometric constraints and a method of computer simulation for overall system is verified. Finally, it is illustrated that even in case of there exists a sensory feedback from sensing data of the rotational angle of the object to command inputs control of joint and this feedback connection from sensing data to control grasping of machinery parts.

• 대한한방부인과학회지
• /
• 제27권1호
• /
• pp.167-175
• /
• 2014

Purpose: This study was performed to find correlations between Edema Index and Pulse Energy in early postpartum period. Methods: Fiftynine postpartum women were participated in this study which was conducted with Inbody 720 (Biospace Co. Ltd) and 3D Blood Pressure Pulse Analyzer (3D-MAC). Edema Index (Extra Cellular Water/Total Body Water) calculated after body composition analysis and 3D-MAC result (Pulse Energy) were analysed within a week after delivery. Results: The results were as follows 1. Edema Indexes of the upper, lower limbs, trunk and whole body were associated with each other respectively. 2. Edema Indexes and Right Kwan pulse energy had significant positive correlation. 3. Right Kwan pulse energy showed positive correlations with Left Kwan, Right Chon, Right Cheok. Conclusions: Viscera associated with Postpartum Edema are Spleen, Lung, Liver and Vital Gate. The most important thing is thought to be Spleen.