• The Journal of the Acoustical Society of Korea
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• v.43 no.4
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• pp.455-465
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• 2024

In shallow water, the array invariant, known as the effective range estimation method, is developed based on the broadband dispersion characteristics in an ideal waveguide, which can be summarized by the waveguide invariant. It is robust enough to estimate both the array tilt and range simultaneously, even in situations where array tilt exists. Recently, it has been extended to fully consider the angle dependence of the waveguide invariant. However, applying the array invariant in range-dependent environments instead of range-independent environments can lead to range estimation errors due to bathymetry mismatch. In this paper, we interpret such range estimation errors by introducing the concept of effective range. Through numerical simulations and experimental data in a weakly range-dependent environment, we demonstrate the relationship between range estimation errors and effective range.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.05a
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• pp.101-104
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• 2008

현대에 컴퓨터를 기반으로 무선으로 데이터를 측정하고 제어하는 device들이 보편화 되어있으며, 낮은 가격으로 높은 성능을 낼 수 있는 device들이 각광 받고 있다. 그리고 산업 환경에서 유선 이용이 불가능한 곳이나 직접 사람이 들어갈 수 없는 위험한 장소와 거리 측정할 때 Zigbee 통신 Solution을 이용한다면 공간의 제약 없이 컴퓨터로 데이터를 분석 처리할 수 있다. Zigbee 통신은 기존의 RF나 bluetooth등에 비해 전력 소모에서 효율적이고 battery 사용을 장시간 사용할 수 있는 장점을 가지고 있다. 또한 시스템 구현 비용이 아주 저렴하기 때문에 네트워크에 많은 노드들을 설치 할 수 있다. 이에 본 논문에서 구현한 거리 측정 무선 송/수신 시스템은 여러 개의 LMC(Laser Measuring Control)와 이에 상응하는 여러 개의 Slave Zigbee에서 하나의 Master Zigbee 까지 무선으로 데이터를 송신한다. Master Zigbee는 LMC에서 측정한 데이터들을 수신 받아 컴퓨터로의 처리를 하고자 하였다.

• Journal of Energy Engineering
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• v.24 no.2
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• pp.17-21
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• 2015

Restriction orifices in the feed and bleed circuit of nuclear power plant are designed using computer program capable of handling multiple hole cascade orifice assembly. Single hole stages of orifice assembly are alternated with multihole stages where necessary. The distance between stages is such that it allows full pressure recovery. The minimum static pressure is higher than vapor pressure at the operating temperature so that cavitation does not occur. Piping sizes are reviewed and increased if necessary to improve rigidity.

• Environmental and Resource Economics Review
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• v.5 no.2
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• pp.317-327
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• 1996

소비자예치금제를 도입하는 경우 적정예치금을 설정하기 위해서는 용기재활용에 따른 소비자 불편비용의 산출이 필요하다. 본 논문에서는 폐음료용기에 의한 외부효과를 내재화하는 정책적 수단의 하나인 소비자예치금제 동에서 소비자의 용기반환에 따른 불편비용을 추정하는 방법 및 실험적 분석결과를 제시하였다. 비시장재화의 가치평가에 널리 응용되고 있는 가상적 가치평가법(Contigent Valuation Method)을 이용하여 용기반환시 보상받고자 하는 수취의사액, 즉 불편비용에 상응하는 액수를 추정한 결과 용기반환장소 까지의 거리가 멀어짐에 따라 소비자의 불편비용은 증가하고 용기 하나당 평균 16원의 불편비용이 발생하는 것으로 나타났다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.10
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• pp.1830-1834
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• 2008

At the present day, devices for measurement and control of data by wireless based computer have been generalized. The devices with low cost and high performance have been spotlighted. If Zigbee communication solution is used in dangerous places and places that can not in use wire communication, computer can process data without limitation. Zigbee communication solution is effective in power consumption as compared with RF or bluetooth and can use battery. System cost of Zigbee also is very low, so can install lots of nodes. The system made in this paper transmit by wireless many LMCs(Laser Measuring Control) of wireless transmission system for distance measurement and many slave Zigbee to a master Zigbee.

• Electrical & Electronic Materials
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• v.5 no.4
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• pp.430-438
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• 1992

본 논문은 단로기의 조작 또는 전력기기의 고장시에 흐르는 급준성 대전류에 의하여 발생하는 자계의 측정이 가능한 새로운 센서의 개발에 대하여 기술한다. 동축케이블을 이용한 자기적분형 자계센서의 동작원리 및 설계방법 등에 대하여 이론적으로 해석하고 인가된 자계에 대한 센서응답을 정확하게 결정할 수 있는 교정실험을 수행하였다. 또한 센서의 동작원리에 상응하는 이론적 모델을 제안하였다. 시제작된 자계센서는 적분저항의 증가와 더불어 감지전압이 상승하고 감쇠시간은 줄어드는 특성을 나타내었다. 과도대전류에 의하여 유발되는 방사자계는 거리의 제곱에 반비례하는 특성을 보였으며 전자기기의 보호를 위한 전자차폐장치의 설계시 방사자계성분에 대한 영향을 고려하여야 됨을 확인하였다.

• Journal of the Korean earth science society
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• v.32 no.1
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• pp.152-157
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• 2011

Lg amplitude decrease $Q^{-1}$ becomes very important when harzadous earthquakes occurred in neighbor nations such as Japan and China because the Lg phase is the largest seismic phase in Korea. The values of Lg $Q^{-1}$ are correlated with seismic activities from the RTSM for IRIS data with long pair distance of stations and events. The Japanese paths crossing the East Sea (Sea of Japan) show high $Q^{-1}$ values related with seismicity and oceanic crust. The paths of Shanghai having the moderate seismicity show the second highest values followed by the Japanese region, while the paths between Manchuria and the Korean Peninsula exhibit low values associated with the low seismicity of the regions.

• Journal of the Korean earth science society
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• v.41 no.5
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• pp.478-489
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• 2020

This study presents an analysis of infrasonic signals from two accidental explosions in Gwangyang city, Jeonnam Province, Korea, on December 24, 2019, recorded at 12 infrasound stations located 151-435 km away. Infrasound propagation refracted at an altitude of ~40 km owing to higher stratospheric wind in the NNW direction, resulting in favorable detection at stations in that direction. However, tropospheric phases were observed at stations located in the NE and E directions from the explosion site because of the strong west wind jet formed at ~10 km. The transmission losses on the propagation path were calculated using the effective sound velocity structure and parabolic equation modeling. Based on the losses, the observed signal amplitudes were corrected, and overpressures were estimated at the reference distance. From the overpressures, the source energy was evaluated through the overpressure-explosive charge relationship. The two explosions were found to have energies equivalent to 14 and 65 kg TNT, respectively. At the first explosion, a flying fragment forced by an explosive shock wave was observed in the air. The energy causing the flying fragment was estimated to be equivalent to 49 kg or less of TNT, obtained from the relationship between the fragment motion and overpressure. Our infrasound propagation modeling is available to constrain the source energy for remote explosions. To enhance the confidence in energy estimations, further studies are required to reflect the uncertainty of the atmospheric structure models on the estimations and to verify the relationships by various ground truth explosions.

• Journal of Korean Philosophical Society
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• v.145
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• pp.351-380
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• 2018

In every society, citizens must decide how to punish criminals, uphold the virtue of justice, and preserve the security of the community. In doing so, the members of society must ask themselves how they will punish those who carry out the most abhorrent of crimes. Many common responses to such a question is that death is an acceptable punishment for the most severe crimes. But to draw some theoretical distinction between a crime that deserves incarceration and a crime that is so heinous that it deserves capital punishment is subject to three errors. First, what possible line could be drawn? To decide on a particular number of deaths or to employ any standard would be arbitrary. Second, the use of a line would trivialize and undermine the deaths of those whose murderers fell below the standard. Third, any and all executions still are unjust, as the State should not degrade the institution of justice and dehumanize an individual who, although he or she has no respect for other human life, is still a living person. Simply put, all murders are heinous, all are completely unacceptable, and deserve the greatest punishment of the land; however, death as punishment is inappropriate. Also, while this article arrives at the conclusion that the death penalty is an inappropriate form of punishment, I have not offered an acceptable alternative that would appease those who believe capital offenders deserve a punishment that differs in its quality and severity. This is a burden that, admittedly, I am unable to meet. I finally conclude that the death penalty is unjustified retribution. This is the only claim that can effectively shift the intellectual paradigms of the participants in the debate. The continued use of the death penalty in society can only be determined and influenced by the collective conscience of the members of that society. As stated at the outset of this article, it is this essentially moral conflict regarding what is just and degrading that forms the backdrop for the past changes in and the present operation of our system of imposing death as a punishment for crime.

• Animal Systematics, Evolution and Diversity
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• v.18 no.1
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• pp.13-21
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• 2002

To add genetic information to the conservation efforts on grey coral (Naemorhedus caudatus) in Korea, we investigated the pattern of mitochondrial cytochrome b gene sequence (606 bp) of six specimens from two localities in Korea. The corresponding sequences of N. caudatus in China obtained from GenBank were also used. The nucleotide Tamura-Nei distances between each of four haplotypes of N. caudatus in Korea and the haplotype of N. caudatus in China varied from 0.0650 to 0.0803: N. caudatus revealed high level of sequence diversity in Bovidae. In N. caudatus in Korea, the distances among three haplotypes at Yanggu were 0.0151 to 0.0185, and it suggests that the genetic diversity of Yanggu population was decreased in low level. Moreover, the distances between each of three haplotypes at Yanggu and one haplotype at Samcheok were 0.0343 to 0.0489. It indicates that habitat isolation caused the continuous increase of genetic distance with geographic distance in N. caudatus, and various conservation plans for mitigating the loss of genetic diversity in Korea have to be in immediate action. To clarify the taxonomic status of N. caudatus, the sequence (276 bp) of N. goral available from GenBank were also utilized, and n goral was not distinct from N. caudatus. It suggests that they may be conspecific, but further analyses with additional specimens of two species are necessary.