• The KIPS Transactions:PartC
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• v.17C no.1
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• pp.15-26
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• 2010

Social Networks such as 'Facebook' and 'Myspace' are regarded as useful tools for people to share interests and maintain or expand relationships with other people. However, they pose the risk that personal information can be exposed to other people without explicit permission from the information owner. Therefore, we need a solution for this problem. Although existing social network sites allow users to specify the exposing range or users who can access their personal information, this cannot be a practical solution because the information can still be revealed to third parties through the permitted users albeit unintentionally. Usually, people allow the access of unknown person to personal data in online social networks and this implies the possibility of information leakage. We could use an access control method based on trust value, but this has the limitation that it cannot reflect the quantitative risk of information leakage. As a solution to this problem, this paper proposes an access control method based on a synthesized metric from trust and risk factors. Our various experiments show that the risk of information leakage can play an important role in the access control of online social networks.

• Journal of Korean Society of Transportation
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• v.22 no.6
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• pp.145-157
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• 2004

Microscopic freeway simulation models project the uncertain values of performance measures for subject traffic conditions by explaining drivers' driving behavior with lane changing and car-following models. However, the existing lane changing models are limited to gap acceptance oriented passive behavior of drivers and not able to capture more-or-less aggressive driving behavior(e.g. cut-in lane changing) ordinarily obseved in field. This paper suggests the definition of cut-inlane changing and presents its characteristics based on the findings from two different freeway on- and off-ramp sections. In addition, this paper proposes a new lane changing model capable of handling both passive and active drivers' driving behavior for better performance of simulations. The proposed lane changing model was tested with Hanyang Simulatin (HYTSIM), a microscopic freeway simulation program developed for this study. The HYTSIM simulation results reflecting the performance of the proposed lane changing model were compared against the field data. The test results showed that the distribution of gaps collected when vehicles change lanes were statistically identical to the field data at 95% confidence level.

• Korean Journal of Health Education and Promotion
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• v.27 no.5
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• pp.1-14
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• 2010

Objectives: This study is an explorative study for developing an instrument to measure habitual physical activity level of school-aged children. Methods: HPAQ-S consists of 41 items and a self-reported 5-day recall instrument designed to assess habitual physical activity level for school-aged children. For the validity and reliability test, a sample consisted of 28 children, aged 10-11 years old. Results: 41 question items showed an acceptable internal consistency (cronbach's alpha=.89). A significant positive correlation with the pedometer results (r=.69, p<.001) and with Borg's questionnaire (r=.76, p<.001) support the validity of HPAQ-S. Conclusion: HPAQ-S may be more useful for measuring habitual physical activity level of elementary school-aged children in large populations.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.7
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• pp.175-183
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• 2017

In this study, the LINC project is finished and a new LINC+ has begun. For the settlement of mutual cooperation in universities and corporations, the main agenda of LINC+ project, this research attempts to find factors that are important to industries rather than the measurement of performance closely related to universities. From the companies' perspective, it is not easy to measure how much they are benefiting from mutual cooperation, although there are quantitative performance determinants such as sales, employment and export growth. Therefore, while estimating the satisfaction of industrial-educational cooperation and simultaneously estimating the satisfaction's effect to the development of companies, we try to estimate the contribution of satisfaction towards company development through subjective indicators. Through these efforts, we will raise the credibility of government policies through the cultivation of talented individuals who are customized to the industry through the cultivation of "Industry-Leading Universities" that we intend to pursue through the implementation of LINC+ business, and small and medium enterprises. Innovative support and the cooperation of industry-universities will increase job creation and ensure consistent industry. We will contribute to the mutual development of universities and industries.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.12B
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• pp.815-825
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• 2007

It is necessary to establish a systematic framework where the performance of governmental funding projects can be evaluated just-in-time as well as objectively regarding IT small and medium-sized enterprises and venture business. In this study, a framework is proposed for the performance evaluation using Data Envelopment Analysis (DEA) and a case study is illustrated with an empirical dataset. Especially, in order to enhance the reliability of optimal solutions, a DEA/AR-I revised model is developed by adding Acceptance Region (AR) Type I constraints into the DEA basic model. Based on the procedure and the models, it is considered that an 'efficiency score' can be calculated as a guideline for conducting successive performance evaluation processes fast. As for major governmental funding projects with respect to 'IT SMERP 2010 Plan', performance evaluations are discussed concerning between projects as well as between corporate entities within each project.

• The Korean Journal of Elementary Counseling
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• v.11 no.3
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• pp.351-369
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• 2012

The purpose of this study is to examine the psychometric properties of the Korean Children's Rejection Sensitivity Questionnaire (K-CRSQ). In order to investigate the reliability and validity of the K-CRSQ, the data were collected from 286 elementary students. The results are as follow : Internal consistency and test -retest reliability of the K-CRSQ were .83~.89, .72~.79, respectively. To test the convergent and discriminant validity, participants were separated into two samples and administered the K-CRSQ and ten validity indices. The correlation of K-CRSQ and validity indices scores suggested that the convergent and discriminant validity are high. High rejection sensitivity group revealed high score on intentional attribution, depression, anxiety, and aggression. In contrast, low rejection sensitivity group revealed high score on self-esteem, perceived competence, and social support. The results were compared with previous studies and the implication and limitation were discussed.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.44 no.4 s.316
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• pp.101-108
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• 2007

Parallel processing algorithms, coupled with advanced networking and distributed computing architectures, improve the overall computational performance, dependability, and versatility of a digital signal processing system In this paper, novel parallel algorithms are introduced and investigated for advanced sonar algorithm, conventional matched-field processing (CMFP). Based on a specific domain, each parallel algorithm decomposes the sequential workload in order to obtain scalable parallel speedup. Depending on the processing requirement of the algorithm, the computational performance of the parallel algorithm reveals different characteristics. The high-complexity algorithm, CMFP shows scalable parallel performance on the array of DSP processors. The impact on parallel performance due to workload balancing, communication scheme, algorithm complexity, processor speed, network performance, and testbed configuration is explored.

• Journal of the Korean Data and Information Science Society
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• v.24 no.6
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• pp.1263-1274
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• 2013

VaR (value at risk), which represents the expectation of the worst loss that may occur over a period of time within a given level of confidence, is currently used by various financial institutions for the purpose of risk management. In the majority of previous studies, the probability of return has been modeled with normal distribution. Recently Chen et al. (2010) measured VaR with asymmetric Laplacian distribution. However, it is difficult to estimate the mode, the skewness, and the degree of variance that determine the shape of an asymmetric Laplacian distribution with limited data in the real-world market. In this paper, we show that the VaR estimated with (symmetric) Laplacian distribution model provides more accuracy than those with normal distribution model or asymmetric Laplacian distribution model with real world stock market data and with various statistical measures.

• The Journal of the Korea Contents Association
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• v.11 no.10
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• pp.342-348
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• 2011

The study aimed to compare the validity between the abdominal ultrasonographic(US) grading system of fatty liver and histologic grading system of fatty liver in living liver donor candidates. As the fatty liver is defined as pathologic total fat >10%, US validity was sensitivity 64.6%, specificity 68%, positive predictive value 76.8%, negative predictive value 54%. As the strict data handling on US grading normal, mild fatty liver are negative, moderate fatty liver is positive, US validity was sensitivity 26.8%, specificity 100%, positive predictive value 100%, negative predictive value 45.5%. ROC curve analysis according to different cut off value of liver-to-kidney brightness ratio was Area under ROC curve=0.859(95% CI=0.795~0.922, state variable= total fat 10%). There were statistically significant difference( p<0.001). Ultrasonography for the fatty diagnosis showed a high validity to predict the result of histology grade of fatty liver.

• Tunnel and Underground Space
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• v.19 no.5
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• pp.463-472
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• 2009

Many old domestic mines were excavated with the room and pillar method or the sublevel caving method and they involve the great possibility of surface subsidence, especially in the shallow depth mines. In most of these cases, the mine roadways and openings are very irregular in shape and the information about the local geology is uncertain. Consequently it is not simple to standardize the estimation method for the possibility of subsidence, especially the sinkhole subsidence. In this study, the fuzzy reasoning method has been applied for development of estimating the possibility of subsidence occurrence in abandoned mine area. This method has the advantage in producing the reliable estimation results with a simple performance procedure even when the precise information on the local geology and mining conditions is rare. For the verification of applicability of this method, the developed method has been applied to Kumho mine in Bonghwa, Kyungbook province and the Choong-ju mine in Iryu, Choongbook province where the surface subsidence occurred already.