• Science of Emotion and Sensibility
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• v.12 no.4
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• pp.557-564
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• 2009

For scoring polygraph charts, the Prosecutors' Office of the Republic of Korea uses a consistency criterion in which an elevated signal on one physiological channel is scored as a deceptive response only if the signal is also elevated on other channels. In the current study, the effects of this scoring criterion on reliability and accuracy (validity) of polygraph scores were assessed. Polygraph tests on 26 suspects were evaluated twice by the same examiners. The examiners used the consistency criterion in the first evaluation. In the second evaluation, the examiners were prevented from using the criterion; the signals from each physiological channel were separated and randomly arranged before they were rescored by the same examiner. Reliability was assessed by the variation among the scores for each suspect. Accuracy was assessed by establishing a standard, based on a Latent Class Analysis model, using the results of polygraph tests on each of 182 additional suspects. Reliability and accuracy were both improved by the use of the consistency criterion which therefore was recommended.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.3
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• pp.997-1005
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• 2013

Since the cross-sectional shape of the Nakdong river is compound type, the water stage rises up to the top of the flood plane, as the flow discharge increases during the extreme rain storm in summer. The recent increase of rainfall intensity and flood frequency results in the immersions of parks and hydrophilic facilities located in the flood plain. Therefore it is necessary to analyze the hydraulic characteristics evolved by the extreme rain storm in the flood plain. The study reach ranging from the Gangjeong Goryeong Weir and the Dalseong Weir, where several hydraulic facilities are located along the channel, was selected and numerical simulations were conducted for 42 hours including the peak flood of the typhoon Sanba. The 2-D transient model, FaSTMECH was employed and the accuracy of the model was assessed by comparing the water level between the simulation results and the measured ones at a gauging station. It showed a high correlation with $R^2$ of 0.990, AME of 0.195, and RMSE of 0.252. In addition, the inundation time, the inundation depth, the inundation velocity, and the shear stress variation in the flood plain facilities were analyzed.

• Investigative Magnetic Resonance Imaging
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• v.9 no.1
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• pp.36-42
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• 2005

Purpose : To develop a novel approach to calculate the sensitivity profiles of the phased array coil for use in non-uniform intensity correction. Materials and Methods : The proposed intensity correction method estimates the sensitivity profile of the coil to extract intensity variations that represent the scanned image. The sensitivity profile is estimated by fitting a non-linear curve to various angles of projections through the imaged object in order to eliminate the high-frequency image content. Filtered back projection is then used to compute the estimates of the sensitivity profile of each coil. The method was applied both to phantom and brain images from 8-channel phased-array coil and 4-channel phased-array coil, respectively. Results : Intensity-corrected images from the proposed method have more uniform intensity than those from the commonly used 'sum-of-squares' approach. By using the proposed correction method, the intensity variation was reduced to $6.1\%$ from $13.1\%$, acquired from the 'sum-of-squares'. Conclusion : The proposed method is more effective at correcting the intensity non-uniformity of the phased-array surface-coil images than the conventional 'sum-of-squares' method.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.4
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• pp.546-551
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• 2020

Generally, surface vessels have many compartments for operation and living quarters, and each compartment is an important space for the ship's survivability. During ship construction, a compartment leak test is necessary and is carried out on each vessel. However, the current test method is in doubt when looking at the actual test results. The reason is that only one pressure gauge is used for the measurement to check the air, so an uncomprehended phenomenon is detected during group compartment leak tests. From this point of view, an improved test device and method are needed. In this study, a multi-channel data acquisition device with multiple pressure sensors is proposed to detect each compartment's pressure variation or pressure drop. This test is a more confidential compartment leak test than the current method, and the test device can show real-time pressure detection values of each of the pressure sensors, which are installed in each compartment, including unmanned space.

• The Journal of Engineering Geology
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• v.24 no.4
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• pp.631-641
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• 2014

Characteristics of water-level changes in the Temporary Gulpocheon Discharge Channel were identified by observing and analyzing changes in the subterranean water level induced by hydrological stresses the underground aquifer. The subterranean water level refers to the level at which the pressure of subterranean water passing through the corresponding position has an equipotential value that is in equilibrium with the atmospheric pressure at that location. This water level is not fixed but changes in response to hydrological stress. It can be identified by repeatedly measuring the distance from the observation point to the surface of the subterranean water. The subterranean water-level change equation and the variance range of the hydrological curve of subterranean water over 24 hours at the Gimpo-Gimpo National Groundwater Monitoring Network (NGMN) were used as assessment factors. The variance characteristics of the subterranean water at the 18 monitoring system locations were classified into three impact, observational wish, and non-impact. The impact type accounted for 50% of the subterranean water of and accurately reflected the water-level changes due to hydrological stress, showing that distance is the major controlling factor. The observational wish type accounted for 27.8% of the subterranean water, and one of the two assessment factors did not meet the assessment factors. The nonimpact type accounted for 22.2% of the subterranean water. This type satisfied the two assessment factors and represents subterranean water-level changes response to precipitation.

• 한국해양학회지
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• v.30 no.4
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• pp.237-249
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• 1995

To understand the cross-sectional structures of temperature, salinity and current across the Korea Strait, field measurements were carried out for the period of May 2 to 20, 1994. Using the R/V Tam Yang, detailed CTD profiles and ADCP records were obtained and used to examine the mean and variability field on two time scales (15 days and 25 hours). A sharp coastal front in the middle of the Korea Strait exists across which two different water masses, i.e., warm and saline water in the eastern side and cold and less saline water in the western side are neighboring. We observed highly variable field of T and S apparently caused by the westward movement of warm and saline water mass. Short-term fluctuations of T and S in the middle layer are remarkable and their importance was analysed as the first Eigen mode accounting for more than 50% of total variances. The currents in th Korea Strait are strongly influenced by tidal currents with spring and neap variation whose maximum speed ranges 80-90 and 60-70 cm/s respectively near the central portion of the channel. Strong southward tidal current could even mask the Tsushima Current completely. Results of harmonic analysis show that the magnitudes of semidiurnal, diurnal and mean components of currents are comparable to each other at spring and neap tide conditions. The volume transport across the western channel of the Korea Strait were estimated to be 2.1 Sv at neap tide condition and 3.4 Sv at spring tide condition.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.16 no.3
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• pp.163-180
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• 1983

Fish larvae were collected from Changson channel, Namhae over the period from June 1982 to May 1983. A total of 44 species (33 families and 41 genera) were identified and described with morphological feature. The larvae of Cyclopsis tentacularis is newly reported in the Korean waters. Abundance of the species in numbers was as follows : Engraulis japonica $86.56\%$, Acanthogobius flavimanus $5.91\%$, Enedrias sp. $1.71\%$, Sebastes inermis $1.18\%$, Leucopsarion petersi $0.78\%$, Hexagrammos otakii $0.68\%$. According to variation of seasonal abundance the larvae were grouped into three seasonal groups as follows : Spring type: Engraulis japonica, Astroconger sp., Enedrias sp., Leucopsarion petersi, Sebastes inermis, Hexagrammos otakii Summer type : Engraulis japonica, Leiognathus nuchalis, Acanthogobius flavimanus, Omobranchus elegans, Syngnathus schlegeri. Winter type: Enedrias sp.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.1
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• pp.29-36
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• 2012

In Wireless Sensor Network(WSN)s, the detection of precise location of each node is essential for utilizing sensing data acquired from sensor nodes effectively. Among various location methods, the received signal strength(RSS) based localization scheme is mostly preferable in many applications because it can be easily implemented without any additional hardware cost. Since a RSS-based localization scheme is mainly affected by radio channel or obstacles such as building and mountain between two nodes, the localization error can be inevitable. To enhance the accuracy of localization in RSS-based localization scheme, a number of RSS measurements are needed, which results in the energy consumption. In this paper, a RSS based localization using Bayesian Compressive Sensing(BSS) with path-loss exponent estimation is proposed to improve the accuracy of localization in the energy-efficient way. In the propose scheme, we can increase the adaptative, reliability and accuracy of localization by estimating the path-loss exponents between nodes, and further we can enhance the energy efficiency by the compressive sensing. Through the simulation, it is shown that the proposed scheme can enhance the location accuracy of multiple unknown nodes with fewer RSS measurements and is robust against the channel variation.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.11
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• pp.1149-1155
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• 2003

OFDM/SFH(orthogonal frequency division multiplexing/slow frequency hopping) system is the combination of OFDM communication system with frequency hopping(FH) method and OFDM/DS(orthogonal frequency division multiplexing/direct sequence) system combines the OFDM communication system with direct sequence(DS) method in terms of PN(pseudo noise) sequence. These two systems are also can be used for anti-jamming. In this study we analyze performances of OFDM/SFH system and OFDM/DS system with the equal information rate in partial band jamming and tone jamming channel. We find BER(bit error rate) in the variation of JFR(jamming fractional ratio) and JSR(jamming to signal power ratio) of the partial band jamming. Also, BER is found in the several JSR of the single tone or multi tone jamming. OFDM/DS system shows better performance than OFDM/SFH system in partial band jamming environment. OFDM/DS system has about 2.5 ㏈ SNR(signal to noise power ratio) gains than OFDM/SFH system when JFR=4/16 and JSR=0 ㏈ to meet BER=10$\^$-3/. However, OFDM/SFH system has about 3 ㏈ SNR gains than OFDM/DS system at single tone jamming of JSR=5 ㏈. In multi tone jamming, performance of OFDM/SFH system is considerably degraded than OFDM/DS system.

• Journal of Korea Water Resources Association
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• v.48 no.2
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• pp.91-103
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• 2015

This paper presents the systematic approach to positively skewed shape of instantaneous unit hydrograph (IUH), that is one of the universal features of hydrologic response function. To this end an analytical expression of statistical moments for IUH is derived within the framework of geomorphologic instantaneous unit hydrograph (GIUH) theory and quantified according to the concept of hydrodynamic, geomorphologic and kinematic heterogeneity. There is a big scale difference between hillslope and channel flow path system. Although the former has the much smaller level of scale its variation coefficient tends to be higher and coefficient of skewness has the different trend than the latter. The shape of IUH is likely to be much more affected by kinematic heterogeneity rather than hydrodynamic heterogeneity and its combined effect with geomorphologic heterogeneity is the major cause of skewing hydrologic response function. Statistical features of hillslope and channel flow path can be transferred into hydrologic response function in the form of dimensionless statistics and their relative importance forms the general shape of hydrologic response function.