• 해양환경안전학회지
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• 제19권3호
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• pp.264-269
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• 2013

This paper is to investigate propagation path characteristics of GPS potential jamming signal. To do this, the spherical ground diffraction model is applied to the potential jamming scenario referred to the GPS jamming events occurred in recent years. The fundamental theory on the propagation path loss is discussed and a specific model is applied to several vehicles types which have own heights of antennas in order to compare their propagation path loss values at same 2-D location. The transmitting powers are appropriately given as the ordinary GPS jamming events. And then the received powers in dBW are obtained with given transmitting powers and the estimated total loss. The result of received jamming power at various locations due to the given scenario was distinct. For example, propagation loss values were estimated as -147 ~ -142dBW and -167 ~ -162dBW in $10^6W$ and $10^4W$, respectively. This computation result of the loss can be seriously considered with the tolerable jammer power against L1- C/A GPS receiver under any real jamming situations.

• 산경연구논집
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• 제3권2호
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• pp.5-16
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• 2012

Purpose - Distribution channels cannot function without cooperation. While evidence suggests channel power plays a fundamental role in fostering successful manufacturer-dealer channel cooperation in Western countries distribution systems, little is known empirically as to how dealers' possession of non-mediated powers influence SME manufacturers' cooperation in Asian developing countries. Research design, data, methodology - Drawing upon the extant distribution channels literatures; this study conceptualizes a model and examines the effects of dealer's non-mediated powers on manufacturing SME firms, as well as the mediating influence of trust, relationship satisfaction and commitment. A survey of 400 manufacturing SMEs in Taiwan empirically supports the proposed hypothesis. Results - The model is acceptable in terms of overall goodness of fit. Acceptable model fit are indicated by χ²/(df): 2.35, GFI≧.90; RMSEA values≦ .08; IFI, TLI and CFI values≧.90. Our results indicate that, GFI (0.910), IFI (0.937), TLI (0.903), CFI (0.936), and RMSEA (0.079) and therefore, achieved the suggested thresholds. Conclusions - The results of this study have some managerial implications for managers in the dealer's firms. The overall implication from the findings is that managers can utilize expert, referent and traditional legitimate powers to attain channel cooperation with manufacturing SMEs in addition to garnering their trust, relationship satisfaction and commitment.

• 대한원격탐사학회지
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• 제33권1호
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• pp.47-60
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• 2017

The permafrost active layer plays an important role in permafrost dynamics. Ecological patterns, processes, and water and ice contents in the active layer are spatially and temporally complex depending on landscape heterogeneity and local-scale variations in hydrological processes. Although there has been emerging interest in the application of optical remote sensing techniques to permafrost environments, optical sensors are significantly limited in accessing information on near surface geo-cryological conditions. The primary objective of this study was to investigate capability of L-band SAR data for monitoring spatio-temporal variability of permafrost ecosystems and underlying soil conditions. This study exploits information from different polarimetric SAR observables in relation to permafrost environmental conditions. Experimental results show that each polarimetric radar observable conveys different information on permafrost environments. In the case of the dual-pol mode, the radar observables consist of two backscattering powers and one correlation coefficient between polarimetric channels. Among them, the dual-pol scattering powers are highly sensitive to freeze/thaw transition and can discriminate grasslands or ponds in thermokarst area from other permafrost ecosystems. However, it is difficult to identify the ground conditions with dual-pol observables. Additional backscattering powers and correlation coefficients obtained from quad-pol mode help understanding seasonal variations ofradar scattering and assessing geo-cryological information on soil layers. In particular, co-pol coherences atHV-basis and circular-basis were found to be very usefultools for mapping and monitoring near surface soil properties.

• 한국통신학회논문지
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• 제17권1호
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• pp.29-37
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• 1992

본 논문에서는 일반적 형태의 상승 Cosine함수와 그 n-제곱 함수에 대한 Fourier변환을 해석적으로 구하는 새롭고 용이한 방법을 제안하였다. 이는 (1+D)형 부분응답 시스템의 개념에 근거를 두고 있으며, 또 함수에 의하여 변환되는 기존의 방법에 비하여 매우 간결함을 보인다. 특히, 이러한 방법에 의하여 유도되는 해는 각각의 차수에 대하여 다루기 용이한 세 함수의 합으로 주어지며, 이들은 차수에 따라 순환적 관계를 유지한다. 따라서 이러한 과정은 컴퓨터에 의한 수치적 변환에 대해서도 매우 잘 적용된다.

• International Journal of Reliability and Applications
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• 제7권2호
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• pp.167-175
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• 2006

Effective and quick methods that are easy to carry out even by hand, or easy to be programmed by hand-held calculators are needed for assessing the sizes of contrasts of unreplicated $2^P$ factorial designs. Moreover, they have the advantage to use the original numerical measurements which makes the analysis easier to explain. Basically, Lenth (1989) is one of the most familiar of such quick and powerful methods. Later on, Aboukalam (2001) proposes under constant effects an alternative sophisticated method to Lenth's method. The proposed method is the supreme from two considerable powers. The first utmost indicates less inflation deficiency while the other utmost indicates less shrinkage deficiency. Also under constant effects, Al-Shiha (2006) introduces an alternative quick method which is less shrinkage deficiency while the inflation deficiency is the same. If effects are random, Aboukalam (2005) introduces an alternative quick method in which the first power is favored as long as the second power is within a small margin. In the spirit of quickness and fixed effects, this article adds another method which is supreme from the two considerable powers. The method is based on a one step of the scale-part of a suggested M-estimate for location. Explicitly, we suggest adapting the skipped median (ASKM) estimate. Critical values of ASKM-method, for several sample sizes often used, are empirically computed.

• Journal of Contemporary Eastern Asia
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• 제20권2호
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• pp.157-173
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• 2021

In the transition to a multipolar international system, the literature has focused on great power competition while little attention has been given to the strategic possibilities of smaller states. However, as a result of globalization, states are so closely interconnected that the primary strategies of even major powers are not to achieve zero-sum solutions but to create asymmetric dependency through which they can influence the behavior of other states and non-state actors. States are assisted in this effort by a variety of tools, including setting up institutions, direct economic influence and through building different forms of infrastructure connectivity networks. By discussing asymmetric dependency situations from the perspective of the great powers, the literature presents smaller states primarily as passive actors, paralyzed by their dependence on great powers. Our paper argues that interdependence allows smaller states to effectively influence larger actors and examines strategies from which smaller states can choose in order to influence the behavior of larger states. Despite an extremely asymmetric relationship between Myanmar and China, actors in Myanmar have sought to influence China's Myanmar policy. We examine a case study of the Myitsone Dam, including Myanmar's strategic aims, chosen strategy and limitations in maneuvering space. Semi-structured interviews with local decision-makers and stakeholders are conducted in order to portray the full picture. Our study concludes that further research on the influencing strategies of small states in response to asymmetric dependence can contribute to a better understanding of the interdependence of states.

• 한국안광학회지
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• 제19권2호
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• pp.231-237
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• 2014

목적: 자동굴절력계의 굴절력 값과 포롭터를 이용한 안경처방 굴절력 값에서, 굴절값 차이의 대소가 나타나는 조건을 연구하였다. 방법: 자동굴절력계(SR-7000)와 자동포롭터(AV-9000)를 이용하여 안질환이 없고, 굴절 이상으로 근용안경을 착용하는 30명을 대상으로 총 60안을 검사 하였다. 검사자에 기인한 굴절력 처방값의 변화를 방지하기 위하여, 2명의 검사자가 동일한 검사 조건에서 피검사자의 눈을 측정하였다. 결과: 통계적으로 2명의 검사자의 굴절력 처방값은 유의할만한 차이가 없었다. 대부분의 측정값에서 포롭터를 이용한 안경처방 굴절력 값이 자동굴절력계를 통해 측정된 굴절력 값보다 작게 측정되었다. 근시에서 (-)구면 굴절력 값이 클수록 자동굴절력계의 측정값과 자동포롭터 처방값 간의 차이가 증가하는 현상은 찾아 볼 수 있었다. 근시성 난시안에서 난시도수의 구간별로 결과를 분석하였다. 난시도수가 증가할수록 자동굴절력계와 자동포롭터 값 사이의 차이는 적어지는 경향을 확인할 수 있었다. 결론: 2명의 검사자의 처방값 간의 차이는 없었다. 자동굴절력계의 굴절력 값과 포롭터를 이용한 안경처방 굴절력 값 차이는 근시나 근시성 난시의 경우 피검사자의 굴절 이상도에 대략 비례한다. 피검사자의 교정 렌즈의 굴절력이 클수록 굴절력 차이가 증가하므로, 교정 렌즈 처방 시 주의가 요구된다.

• 생명과학회지
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• 제19권12호
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• pp.1829-1835
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• 2009

과호흡은 뇌파 측정 시에 사용하는 중요한 부활법 중의 하나이며, 과호흡의 질을 평가하여 결과에 반영하는 것이 진단의 측면에서 중요하다. 본 연구는 과호흡이 제대로 유도되었는지를 살펴보고자 하는 목적으로, 환기량에 따른 뇌파의 변화를 살펴보았다. 쥐를 대상으로 기관 절개를 한 후 삽관하여 인공호흡을 유도하였다. 환기유도 시 조건은 정상 환기량을 160 ml/min으로 하여, 240 ml/min, 300 ml/min의 총 세 군으로 하여, 인공적 과호흡을 유도하였다. 뇌파는 전두부와 두정부에서 측정하였으며 과호흡을 하기 전과 후의 뇌파를 비교하였다. 뇌파는 델타, 세타, 알파, 베타의 네 가지 주파수 영역에서의 파형을 정량적으로 분석하였다. 한편 조직검사 결과, 인공적인 과호흡 유도는 폐조직에 물리적인 손상을 유발하지 않았다. 과호흡을 유도하기 위한 조건인 기관절개술도 뇌파에 미치는 영향을 미치지 않는 것으로 나타났다. 과호흡은 정상환기량의 약 90%까지 증가하였을 때에 적절한 결과를 보였고, 뇌파는 델타파가 가장 우세하였으며 세타, 알파, 베타 순으로 출현 비율이 높았고, 특히 전두부에서 유의적으로 나타났다. 과호흡으로 인한 뇌파의 변화를 살펴보면, 전두부 델타 파워가 12.8%(p<0.01) 증가하였고 전두부의 세타 파워와 알파 파워는 각각 41.3%(p<0.01), 48.6%(p<0.05) 감소하였으며, 베타파워도 41.9%(p<0.05)가 감소하였다. 이상의 결과를 통해 전 두부의 뇌파가 과호흡의 질을 평가할 수 있는 기초 자료가 될 것으로 사료된다.

• 대한수학회논문집
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• 제5권2호
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• pp.147-149
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• 1990

• 한국자기학회:학술대회 개요집
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• 한국자기학회 1999년도 춘계연구발표회 논문개요집
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• pp.110-111
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• 1999