• The Journal of Korean Institute of Communications and Information Sciences
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• v.26 no.6A
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• pp.1107-1116
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• 2001

고속 IP 주소 룩업(lookup)은 고속 인터넷 라우터의 성능을 좌우하는 주요 요소이다. LPM(longest prefix matching) 탐색은 IP 주소 룩업에서 가장 시간이 많이 걸리는 부분이다. PICAM은 고속 LPM 탐색을 위한 파이프라인 CAM 구조로서, 기존 CAM(content addressable memory, 내용 주수화 메모리)을 이용한 방법보다 룩업 테이블의 갱신속도가 빠르면서도 LPM 탐색율이 높은 CAM 구조이다. PICAM은 3단계의 파이프라인으로 구성된다. 단계 1 및 단계 2의 키필드분할수 및 매칭점의 분포에 따라 파이프라인의 성능이 좌우되며, LPM 탐색율이 달라질 수 있다. 본 논문에서는 PICAM의 파이프라인 성능모델을 제시하고, 이산사건 시뮬레이션(discrete event simulation)을 수행하여, 최적의 PICAM 구조를 도출하였다. IP version 4인 경우 키필드분할수를 8로 하고, 부하가 많이 걸리는 키필드블록을 중복 설치하는 것이 최적구조이며, IP version 6인 경우 키필드블록의 개수를 16으로 하는 것이 최적구조다.

• Proceedings of the Korea Multimedia Society Conference
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• 2003.05b
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• pp.179-182
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• 2003

1990년대 초반 Frame-Relay 망이 출현하면서부터 등장한 VPN 기술은 최근에도 많은 연구가 이루어지고 있다. 그러나 VPN을 형성하는 기술들이 매우 다양하고, 그 특성도 달라 실제 이용하는 측면에서는 어떤 기술에 기반한 VPN을 채택해야 하는지에 대한 기준이 분명하지 않다. 이런 기준의 하나로 VPN 기술에 따른 트래픽 부하를 들 수 있다. 따라서 본 논문에서는 현존하는 VPN 기술들에 의해 트래픽 부하가 실제 얼마나 부가하는지에 대한 실험 결과를 보인다. SP의 Frame-Relay나 ATM 망과 연동하여 ISP측에 기반통신망 없는 DSL 서비스 등을 가능케 했던 주역인 L2TP, Microsoft측에서 내어놓은 PPTP, MPLS VPN와 같이 최근에 많은 연구가 되고 있는 IP-VPN의 대표적인 예인 IPSec, 그리고 필드에서 실제 많이 구현되고 있는 조합인 IPSec/L2TP 기술에 대해 인터넷이 배제된 망에서 트래픽 부하를 측정하고 분석하였다. 이에 따라 향후 VPN 기술의 효율성 제고에 지침을 제공하고자 한다.

• Journal of Drive and Control
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• v.19 no.4
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• pp.46-53
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• 2022

RIn this study, a test tractor that could measure various types of agricultural operational loads was developed, and its performance was verified. This tractor could be used to measure the load generated during agricultural work and convert the related data into a database. A test tractor was developed using an 80-kW-rated load tractor, and it could measure various types of field test data, such as engine torque and rpm, wheel torque, PTO(power take-off) torque, hexometer, IMU/INS sensor, steering angle sensor, hydraulic pressure, and flow sensor data. To verify the developed test tractor, a verification test using an agriculture rotavator was performed. The test conditions were L1, L2, and L3 based on the tractor's main and sub-transmission stages, and stages 1 and 2 were selected as the PTO. In a comparison of the analyzed test data, similar tendencies in the test results of this research and other research (Kim's research) were seen. Through this, the developed test tractor was verified. In the future, we plan to conduct research on the tractor developed in this study using various attached working machines.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.5
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• pp.111-120
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• 2021

A tractor is an agricultural machine that performs farm work, such as cultivation, soil preparation, loading, bailing, and transporting, through attached working implements. Farm work must be carried out on time per the growing season of crops. As a result, the reliability of a tractor's transmission is vital. Ideally, the transmission's design should reflect the actual load during agricultural work; however, configuring such a measurement system is time- and cost-intensive. The design and analysis of a transmission are, therefore, mainly performed by empirical methods. In this study, a tractor with a measurement system was used to measure the actual working load in the field. Its hydro-mechanical transmission was then analyzed using the measured load. It was found that the velocity factor, load distribution factor, lubrication factor, roughness factor, relative notch sensitivity factor, and life factor affect the gear strength of the transmission. Also, loading conditions have a significant influence on the reliability of the transmission. It is believed that transmission reliability can be enhanced by analyzing the actual load on the transmission, as performed in this study.

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.6
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• pp.683-687
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• 2010

In this paper, we propose an anycast routing scheme for large-scale wireless mesh networks, which requires only one-hop local information with no flooding overhead. We develop an analytical model for anycast mesh networks based on an electrostatic theory. A finite difference method contributes to achieving gateway load balancing with constant control overheads. We verify the performance of the proposed scheme by simulations.

• Journal of Internet Computing and Services
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• v.7 no.6
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• pp.51-62
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• 2006

The load of this kind of gores, which is heavier than that of any other precedent, and on enormous seamless virtual world characterize the MMORPG(Massively Multiplayer Online Role-Playing Game) genres. In this seamless environment, gamers can usually accept a set of independent spaces, which is being held by independent game servers, os a single big virtual world. Despite the efforts of some developers, gamers are suffered from huge message traffic which comes from the interaction between client and server and the interaction between fold sowers. In this paper, new gore server architecture using MigAgent is proposed which tries to reduce message traffic. Usually, message traffic reaches the climax when a PC(Player Character) is moving to other field server. MigAgent, designed in this thesis, tries to manage this kind of PCs and to ploy o role of user's agent to prepare for the unexpected situation. Improvement of this system is shown by the analysis of the effect of the size ratio of AOI (Area of Interest) and AC (Adjacent Cell).

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.8
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• pp.67-73
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• 2021

In this study, we installed forward and reverse rotation rotavators on a tractor to measure the load in the field and analyze the power consumed. The rotavator is attached to the rear of the tractor and transmits the power applied from the power take off (PTO) of the tractor to the rotating shaft of the rotavator, and it plows or reverses the soil according to the rotational direction of the rotating shaft. Depending on the rotational direction of the rotavator, the power consumed in the tractor engine and the power transmitted to the tractor axle and rotavator also vary, thus, research of load and power is an essential factor in designing the system. As a field test results, 84.1-93.5% power was consumed by the forward rotation rotavator, and 37.8-57.5% power was consumed by the reverse rotation rotavator. In addition, depending on the rotation direction of the rotavator, the power consumed by the tractor was in the order of PTO and axle. Based on the research results, development of reliable rotavator systems would be possible in the future research.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.1
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• pp.1-8
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• 2013

Recently, the automotive technology has developed with electronics and information technology as convergence technology while vehicles had been regarded as machines. Moreover, vehicles are becoming more intelligent and safer devices, assembly of advanced technologies by customers' demand. Even though all of installations of vehicle have attracted as diverting devices, it cause drivers' mistakes like delay of response on traffic condition. Here, we proposed the Field Operational Test (FOT) environment which could be used as driving and road conditions collector(Vehicle motion, Traffic condition, Driver input, Driver state, etc.) for researches about Driver Friendly Intelligent System(SCC, LDWS, etc.), Human Vehicle Interface(Driving Workload, etc.) and Economic Drive Model. Furthermore driving patten and fuel consumption patten of drivers were analyzed by measured data and direction of future research was suggested.

• The KIPS Transactions:PartD
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• v.14D no.6
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• pp.649-656
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• 2007

Today, controller area network(CAN) is a field bus that is nowadays widespread in distributed embedded systems due to its electrical robustness, low price, and deterministic access delay. However, its use safety-critical applications has been controversial due to dependability limitation, such as those arising from its bus topology. Thus it is important to analyze the performance of the network in terms of load of data bus, maximum time delay, communication contention, and others during the design phase of the controller area network. In this paper, a simulation algorithm is introduced to evaluate the communication performance of the vehicle network and apply software base fault injection techniques. This can not only reduce any erratic implementation of the vehicle network but it also improves the reliability of the system.

• 전기의세계
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• v.53 no.7
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• pp.31-35
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• 2004

본 고에서는 현재 개발 및 필드테스트되고 있는 전력품질 보상기기인 STATCOM(Static Compensator), DVR(Dynamic Voltage Restorer), 고속전력절체스위치 SSTS(Solid State Transfer Switch)들이 국내 22.9kV급 배전계통에 도입되어 운용될 경우, 배전계통의 전력품질상의 외란, 즉 voltage sag, voltage swell, interruption등에 대해서도 부하기기가 문제없이 잘 동작할 수 있어야 하는 전력품질향상기기의 성능(전력품질향상기준)에 대한 평가방법 에 대하여 기술하고자 한다. 먼저, 전력품질향상기기인 DVR, D-STATCOM, SSTS들이 만족해야할 전력품질향상기준을 국내 전력 품질 실태를 고려하여 제시하고, 또한, 이들 전력품질향상기기에 대한 국내 배전계통적용에 적합한 성능평가방안을 제안/소개하기로 한다. (중략)