• Journal of Welding and Joining
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• v.12 no.3
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• pp.82-89
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• 1994

In this paper the effect of stress ratio on the fatigue crack growth rate of aluminum alloy A5083-O was examined. The fatigue tests were carried out using CCT (center cracked tension) specimens and CT(compact tension) specimens which were subjected to 0.5 and -1.0 stress ratio respectively. The obtained results are as follows; 1) The $\DeltaK_{th}$ as the function of stress ratio R was introduced in evaluating the fatigue crack growth rate of A5083-O. 2) A new model evaluating the effect of stress ratio on the fatigue crack growth rate was developed over the region of low and high propagation rate.

• The Korean Journal of Pain
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• v.1 no.1
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• pp.9-15
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• 1988

Postherpetic neuralgia, the most feared complication of acute herpes zoster, may agonize the pain clinician because the appropriate management of intractable pain can fail inspite of various and prolonged therapeutic techniques. Of all patients with herpes zoster, approximately 5~10% will develop postherpetic neuralgia. Postherpetic neuralgia is very rare in young patient but very common in patients over 60. In other words, the older, the higher incidence. In our pain clinics, 13 postherpetic neuralgic patients were treated with sympathetic blocks, local infiltration with local anesthetics and steroids, TENS, Laser and various drugs including antiderpressant. The results of management of pain in 13 patents were as follows. 1. Excellent pain control :4(30.8%) 2. Good pain control :3(23.0%) 3. Fair pain control :2(15.4%) 4. No effect :4(30.8%).

• Economic and Environmental Geology
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• v.32 no.1
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• pp.33-41
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• 1999

A new sedimentary basin is reported from the marine multi-channel seismic data which were acquired for the hydrocarbon exploration on the southwestern Korean continental shelf in 1970. Along the southeastern part of Line 1192, the about 60-km-long basin with the thickness of 0.55~1.1 s is observed on the near-trace gather. However, both new and previous 24-fold stack sections fail to show the basin image probably due to its rugged top beneath the shallow water. The boundary contact between the basement with the velocity of about 5200m/s and the basin filling with the velocities of 4300~4700 m/s is unclear. These velocites are calculated from the corresponding shot gathers. Compared with the Haenam Basin, a neighbouring onshore Cretaceous sedimentary basin, we interpret that the new basin includes the volcanics and volcaniclastic sequences deposited in the lacustrine environment. This nonmarine basin was possibly formed as the result of the tectonic movement during the Cretaceous, implying the wide occurrence of the Cretaceous basins over the southern Korean Peninsula as well as its southwestern continental shelf.

• Proceedings of the KIEE Conference
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• 1997.07a
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• pp.346-348
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• 1997

This paper presents microprocessor-based real-time speed and position detection by inductive radio loop in new transportation system, such as magnetically levitated train system, rubber tyred train, and linear-motor car. The constant elapsed time method is used in this study for high accurate detection over a wide speed range. And for reliability and safety of the system, it is duplicated and data-bus level comparison is performed by fail-safe comparator.

• Computers and Concrete
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• v.13 no.6
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• pp.749-764
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• 2014

Structural safety has always been a key preoccupation for engineers responsible for the design of civil engineering projects. One of the mechanisms of structural failure, which has gathered increasing attention over the past few decades, is referred to as 'progressive collapse' which happens when one or several structural members suddenly fail, whatever the cause (accident, attack, seismic loading(.Any weakness in design or construction of structural elements can induce the progressive collapse in structures, during seismic loading. Masonry infill panels have significant influence on structure response against the lateral load. Therefore in this paper, seismic performance and shear strength of R.C frames with brick infill panel under various lateral loading patterns are investigated. This evaluation is performed by nonlinear static analysis. The results provided important information for additional design guidance on seismic safety of RC frames with brick infill panel under progressive collapse.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1999.05a
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• pp.235-239
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• 1999

This thesis is concerned with the development of useful engineering techniques to detect and analyze nonlinearities in mechanical systems. The methods developed are based on the concepts of higher order spectra, in particular the bispectrum. The study of higher order statistics has been dominated by work on the bispectrum. The bispectrum can be viewed as a decomposition of the third moment(skewness) of a signal over frequency and as such is blind to symmetric nonlinearities. Initially auto higher order spectra are studied in detail with particular attention being paid to normalization method. Traditional method based on the bicoherence are studied. Under certain conditions, notably narrow band signals, the above normalization method is shown to fail and so a new technique based on prewhitening the signal in the time domain is developed.

• Journal of Agricultural Extension & Community Development
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• v.27 no.1
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• pp.33-50
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• 2020

This study aims at shedding light on two questions: 1) how livelihood strategies hired by heterogeneous farm households differ and in what aspect, and 2) would the strategy change over time or remain identical across farm types? Using 2013-2017 Farm Economy Survey panel data, we divide the sample farms into 4 sub-groups based on income level and sources. Key findings are as follows. First, regardless of farm types, strong path dependency has been observed. That is, lots of farms are likely (enforced) to maintain the livelihood strategies, accounting for why many farms fail to response to market and/or policy signals. Second, along with compounding risks, farms are more vulnerable to specific sorts risks. Third, based on the findings, we made policy suggestions.

• Journal of Electrical Engineering and Technology
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• v.4 no.1
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• pp.19-27
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• 2009

This paper presents a newly developed optimization algorithm, the Bee Optimization Algorithm (BeeOA), to solve the economic power dispatch (EPD) problem. The authors have developed a derivative free and global optimization technique based on the working of the honey bee. The economic power dispatch problem is a nonlinear constrained optimization problem. Classical optimization techniques fail to provide a global solution and evolutionary algorithms provide only a good enough solution. The proposed approach has been examined and tested on two test systems with different objectives. A simple power dispatch problem is tested first on 6 generators and then the algorithm is demonstrated on 13 thermal unit systems whose incremental fuel cost function takes into account the value point loading effect. The results are promising and show the effectiveness and robustness of the proposed approach over recently reported methods.

• Proceedings of the Korea Information Processing Society Conference
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• 2001.10a
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• pp.283-286
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• 2001

전통의 자기 디스크 형태 저장 장치로의 접근 지연 시간을 줄이고자, 최근에 서로 네트워크로 연결된 컴퓨터간의 메모리 자원들을 파일을 저장하는 장치로써 활용해 볼 수 있는 가상 장치(Network RamDisk)가 개발되었다. 이 시스템은 메모리 공간을 제공해 주는 서버의 노드들이 패리티 그룹(parity group)을 이루는 일종의 software RAID 시스템으로 한 서버의 노드 crash 에 대해 대응하는 것을 고려하지 않아 제 이의 서버가 노드 crash, 프로세스 crash 혹은 데이터 손실을 발생시키면 완전히 데이터를 잃어버리는, 신뢰성이 낮은 문제점이 있다. 본 논문은 클라이언트가 서버측의 노드 crash를 적절히 감지하고 새로운 서버로 fail over 할 수 있는 여러 가지 기법들을 설계하고 구현하였다. 또한 서버 풀(server pool)이라는 가상의 공간을 따로 관리하여 서버들에 대한 메모리 자원 요구 부하를 균등히 분산 시키는 효과도 얻도록 하였다.

• The Pure and Applied Mathematics
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• v.17 no.1
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• pp.1-27
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• 2010

Wu and Zhao [17] provided a semilocal convergence analysis for a Newton-type method on a Banach space setting following the ideas of Frontini and Sormani [9]-[11]. In this study first: we point out inconsistencies between the hypotheses of Theorem 1 and the two examples given in [17], and then, we provide the proof in affine invariant form for this result. Then, we also establish new convergence results with the following advantages over the ones in [17]: weaker hypotheses, and finer error estimates on the distances involved. A numerical example is also provided to show that our results apply in cases other fail [17].