• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.1
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• pp.73-76
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• 2010

The issue of inspection and characterization of microstructures has emerged as a major consideration in design, fabrication, and detection of MEMS devices. However, the conventional measurement techniques, including scanning electron microscopy (SEM) imaging, atomic force microscopy (AFM) scanning, and mechanical surface profiler, require often destructive process or may be difficult to measure with a wafer scale. In this paper, we characterize the surface profiles of microstructures using an optical scanner based on a DVD pick-up module. Scanning images of the microstructures are successfully generated using the intensity of reflected light from different depths of the surface profiles, based on the focus error signal (FES) from photodiodes. It is shown that the proposed optical scanner can be used as an alternative measurement system with high performance and low cost, compared to conventional measurement techniques.

• Economic and Environmental Geology
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• v.36 no.3
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• pp.201-212
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• 2003

Recently, the ability of earthquake detection in the Kyungsang Basin of southeastern Korean Peninsula is greatly improved since seismic stations including seismic network of KIGAM(Korea Institute of Geoscience and Mineral Resources) have been significantly increased. However, a large number of signals from explosions are recorded because of frequent medium to large chemical explosions. The discrimination between natural earthquakes and explosions in the Basin has become an important issue. High frequency local records from 43 earthquakes and 43 explosions with comparable magnitude are selected to establish a reliable discrimination technique in the Basin. Several discrimination techniques in spectral domain using spectral amplitude ratios among Pg, Sg, and Lg waves are widely examined with tile selected data. Among them the Pg/Lg spectral ratio method is appeared to be a good discrimination technique to improve the discrimination power. Multivariate discriminant analysis is also applied to the Pg/Lg spectral ratios. The discrimination power of the Pg/Lg ratios for distance corrected three component record compared to uncorrected vertical component one shows distinct improvement. In the frequency band 4 to 14 Hz, Pg/Lg spectral ratio for distance corrected three component record provides discrimination power with a total misclassification probability of only 0.89%.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.29 no.1
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• pp.55-62
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• 2011

Amidst the raising of climate change in relation to the earth's environment as an international issue, there is a growing interest in forest resources. In particular, Korea faces a period in which we need to control carbon release pursuant to the Convention on Climate Change and the enforcement of the Kyoto Protocol; therefore, the importance of forests is becoming greater. Recently, there has been a focus on light detection and ranging (Lidar) which is a means of acquiring in a short time various necessary pieces of information for forest management as three dimensional geospatial information. In this study, the carbon absorption of a forest was measured by using the Lidar data obtained from the Lidar. Carbon absorption release was calculated on the basis of three criteria involving the minimum height of a tree, the density of the forest, and the minimum area of the forest, which are items proposed by the Forest resources surveyor. Through this study, a method of extracting the carbon absorption of a forest area using the Lidar data quantitatively was confirmed.

• Journal of Preventive Medicine and Public Health
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• v.36 no.3
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• pp.239-247
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• 2003

Objectives : The objectives of this study were to examine the difference in attitude toward health-specific locus-of-control and medical care among western medical students, oriental Medical students, and non-medical school students. Methods : The subjects of this study were 667 students who agreed to respond the questionnaire :212 western medical school students, 190 oriental medical school students, and 205 non-medical school students. The health-specific locus of control was measured by the structured questionnaire developed by Lau and Ware. The attitude toward western and oriental medicine was also measured by the questionnaire. Results : Western medical students and non-medical school students were more likely than oriental medical students to place high value on 'the provider control over health' and 'the general threat to health' scales (F=20.47, F=19.98). But oriental medical school students ranked 'the self control of health' scale as more important than any other locus of control scale (F=19.34). The health specific locus of control was also different from the grade. When trte grade was increased, 'the provider control over health' scale was slowly decreased, especially in western medical students and non medical school students. However, the 'general threat to health' scale was increased in oriental medical students. Western medical school students expressed more positive attitude toward western medicine. Oriental medical school students put a higher score on oriental medicine. Nevertheless, as the grade was increased, the positive attitude toward oriental medicine slightly decreased in oriental medical school students. Conclusions : There is a difference in health-specific locus of control and attitude toward medicine among western medical students, oriental medical students, and non-medical students. The locus of control and attitude of medical students towards medicine may affect both how they behave towards patients and how they help shape future public policy. Therefore, interdisciplinary educational initiatives may be the best way to handle this issue.

• The Korean Journal of Applied Statistics
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• v.21 no.1
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• pp.53-63
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• 2008

It is commonly believed that disease of human or economic traits of livestock are caused not by single gene acting alone, but by multiple genes interacting with one an-other. This issue is difficult due to the limitations of parametric statistical method like as logistic regression for detection of gene effects that are dependent solely on interactions with other genes and with environmental exposures. Multifactor dimensionality reduction (MDR) nonparametric statistical method, to improve the identification of single nucleotide polymorphism (SNP) associated with the Hanwoo(Korean cattle) carcass cold weight, is applied and compared with ANOVA results.

• The KIPS Transactions:PartB
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• v.9B no.3
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• pp.327-336
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• 2002

Texture analysis is an important technique in many image understanding areas, such as perception of surface, object, shape and depth. But the previous works are intend to the issue of only texture segment, that is not capable of acquiring recognition information. No unsupervised method is basased on the recognition of texture in image. we propose a novel approach for efficient texture image analysis that uses unsupervised learning schemes for the texture recognition. The self-organization neural network for multiple texture image identification is based on block-based clustering and merging. The texture features used are the angle and magnitude in orientation-field that might be different from the sample textures. In order to show the performance of the proposed system, After we have attempted to build a various texture images. The final segmentation is achieved by using efficient edge detection algorithm applying to block-based dilation. The experimental results show that the performance of the system Is very successful.

• Journal of the Korea Computer Graphics Society
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• v.23 no.1
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• pp.39-48
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• 2017

We present penetration depth (PD) computation algorithms using explicit Minkowski sum construction ($PD_e$) and implicit Minkowski sum construction ($PD_i$). Minkowski sum construction is the most time consuming part in fast PD computation. In order to address this issue, we find a candidate solution using a centroid difference and motion coherence. Then, $PD_e$ constructs or updates partial Minkowski sum around the candidate solution. In contrast, $PD_i$ constructs only a tangent plane to the Minkowski sums iteratively. In practice, our algorithms can compute PD for complicated models consisting of thousands of triangles in a few milli-seconds. We also discuss the benefits of using different construction of Minkowski sums in the context of PD.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.28 no.5
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• pp.1225-1231
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• 2018

FPGA-based system development is being developed as a form of outsourcing that shortens the development time and reduces the cost. Through the process, the risk of letting the hardware Trojan, which causes malfunctions, seep into the system also increases. Various detection methods are proposed for the issue; however, such type of hardware Trojans is inserted by modifying a bitstream directly and therefore, it is hard to detect with the suggested methods. To detect the type of hardware Trojans, it is essential to reverse-engineer the electric circuit implemented by bitstream to a distinguishable level. Specifically, it is important to reverse-engineer the routing information of the circuit that can identify the input-output flow of the signal. In this paper, we analyze the BIL bitstream reverse-engineering tool-chain that uses the algorithm, which retrieves the routing information from FPGA bitstream, and suggest the method to improve the tool-chain.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38B no.1
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• pp.87-96
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• 2013

Influence propagation is an important research issue in social networks. Influence propagation means that the status or the disposition of nodes get changed by new idea, information and gossip propagated by other nodes. Influenced nodes also make other nodes influenced across the network. The influence propagation problem based on 'word of mouth' referral is to find most influential nodes set in networks to maximize influence. In this paper, we study the influence measuring and finding most influential nodes set in Delay-Tolerant Networks. It is difficult to measure exact influential power in Delay-Tolerant networks where network topology is not stable due to the nodal mobility. In this paper, we propose a distributed scheme that each node constructs $k$-clique community structure and estimates local influential power in Delay-Tolerant Networks. Simulation results show that the influential nodes information estimated by proposed scheme is in agreement with a global view of influential nodes information.

• Toxicological Research
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• v.31 no.3
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• pp.279-288
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• 2015

N-nitrosamines, which are classified as carcinogens by IARC and US EPA, can be easily found in various foods. They are reaction products between nitrogen oxide and secondary amines, but can also be generated during fermentation. Ever since the 1960s, when nitrite, used as a preservative in processed meats, was suspected to generate N-nitrosamines, the usage of the food additive has been debated. However, the benefit of nitrite in food supply could not be ignored and the risk-benefit analysis has become a key issue in the use of the additive. For a risk analysis, an accurate estimation of the hazardous material is necessary; therefore, analytical methods for nitrosamines have continuously evolved from the 1950s. Solid supported liquid-liquid extraction and solid phase extractions have replaced the distillation for the clean-up steps, and tandem mass spectrometry is employed for higher selectivity and sensitivity. In the present study, for a better estimation of N-nitrosamine intake, the total diet study samples were prepared for the N-nitrosamines analysis. In order to obtain the most sensitive results, a partial preparation procedure was developed and modified for different food matrices. Among seven N-nitrosamines (N-nitrosodimethylamine, N-nitrosomethylethylamine, N-nitrosodiethylamine, N-nitrosodibutylamine, N-nitrosopiperidine, N-nitrosopyrrolidine, and N-nitrosomorpholine) analyzed in the present study, N-nitrosodiethylamine has shown the highest detection rate in agricultural foods, while N-nitrosodimethylamine has appeared most frequently in livestock and fishery food products. The concentration of N-nitrosodimethylamine was the highest in seasoning.