• International Journal of Highway Engineering
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• v.13 no.4
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• pp.199-209
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• 2011

In the study of traffic safety, the analysis on factors affecting crash severity and the understanding about their relationship is important to be planning and execute to improve safety of road and traffic facilities. The purpose of this study is to develop a hierarchical binomial logistic model to identify the significant factors affecting fatal injuries and vehicle damages of traffic crashes on freeway. Two models on death and total vehicle damage are developed. The hierarchical structure of response variable is composed of two level, crash-occupant and crash-vehicle. As a result, we have gotten the crash-level random effect from these hierarchical structure as well as the fixed effect of covariates, namely odds ratio. The crash on the main line and in-out section have greater damage than other facilities. Injuries and vehicle damages are severe in case of traffic violations, centerline invasion and speeding. Also, collision crash and fire occurrence is more severe damaged than other crash types. The surrounding environment of surface conditions by climate and visibility conditions by day and night is a significant factor on crash occurrence. On the orher hand, the geometric condition of road isn't.

• Journal of environmental and Sanitary engineering
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• v.14 no.4
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• pp.85-92
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• 1999

Indoor air quality tends to be the dominant contributor to personal exposure because most people spend over 90% of their time indoors. For some contaminants, exposure to indoor air poses a potentially greater health threat than outdoor air exposures. Indoor nitrogen dioxide ($NO_2$) levels are mainly affected gas range, flue gas spillage, kerosene heaters, wood-burning appliances and cigarette smoke. In addition, indoor $NO_2$ levels are influenced by such house characterization as surface reaction and air exchange rate. In this study, the measurements of indoor and outdoor $NO_2$ concentrations were taken using identical protocols, and information was collected on housing characteristics using identical questionnaires in 14 houses out of 15 houses for daily 30 daily 30 days in Brisbane, Australia.The usage of gas range was the most contributing factor in indoor $NO_2$ concentration in relation to house characteristics. Average indoor and outdoor ratios of NO2 concentration in electronic and gas cooking houses were $0.6{\pm}0.1$ and $0.9{\pm}0.2$, respectively. The frequency distributions of $NO_2$ concentration in each house were approximately log-normal Geometric mean of indoor $NO_2$ concentrations of electronic and gas cooking houses for daily 30 days ranged from 2.5 ppm to 11.5 ppm with a mean 6.8 and from 4.7 ppm to 28.6 ppm with a mean 15.6 ppm, respectively. The $NO_2$ concentrations between electronic and gas cooking houses were significantly different (p<0.05). Since each house has different life-style and house characteristics, sampling interval to measure the $NO_2$ levels was recommended above 7 days.

• Journal of Korean Society of Transportation
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• v.26 no.5
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• pp.195-204
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• 2008

When the drivers try to read an information on road signs, they can reach their destinations successfully. In this situation, human factors, road signs and geometric condition regarded as the most important factors for a safe driving should be a well-balanced relationship mutually. This research aims to prove the factors obstructing a safe driving, while drivers try to read an information on road signs for the next destination. For this sake, driving simulator was used and human factors, road signs etc. were considered in this experiment. The statistical analysis indicated what factors disturb a safe driving. The probability function using a Logistic Model was presented in this study. This result and experience will be used as a basic data in designing better road signs.

• Proceedings of the Korean Geotechical Society Conference
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• 2007.09a
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• pp.623-634
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• 2007

The aim of this research is development and verification of resistivity seismic dilatometer (RSDMT) system. The resistivity module for obtaining resistivity-depth plot and seismic module for obtaining wave velocity-depth plot are attached to the conventional flat dilatometer testing equipment. To enhance reliability and repeatability of seismic part in RSDMT, automatic testing system including automatic surface source, PC based data acquisition system and operating program were developed. To obtain real resistivity value of soil, geometric factor for the array of electrodes in RSDMT was derived empirically. The verification studies for the developed RSDMT system were performed at the southeast side of Korea where soil improvement work is planned. SPT, CPT, geophysical subsurface imaging techniques and some laboratory tests were performed for the comparisons. As one penetration of RSDMT, various soil parameters could be obtained. The results of field test showed good repeatability and reliability in every part. From these studies, developed RSDMT system was checked and the effectiveness of this system was verified in light of proper evaluation of geotechnical characteristics of soft soil.

• Journal of Ocean Engineering and Technology
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• v.27 no.1
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• pp.85-92
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• 2013

This paper deals with the resonant type of a WEC (wave energy converter) and the determination method of its geometric parameters which were obtained to construct the robust and optimal structure, respectively. In detail, the optimization problem is formulated with the constraints composed of the response surfaces which stand for the resonance period(heave, pitch) and the meta center height of the buoy. Use of a signal-to-noise ratio calculated from normalized multi-objective results with the weight factor can help to select the robust design level. In order to get the sample data set, the motion responses of the power buoy were analyzed using the BEM (boundary element method)-based commercial code. Also, the optimization result is compared with a robust design for a feasibility study. Finally, the power efficiency of the WEC with the optimum design variables is estimated as the captured wave ratio resulting from absorbed power which mainly related to PTO (power take off) damping. It could be said that the resultant of the WEC design is the economical optimal design which satisfy the given constraints.

• Journal of the Korean Institute of Telematics and Electronics
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• v.26 no.5
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• pp.137-144
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• 1989

A new algorithm is presented which efficiently reports minimum width/space violation in a geometric mask pattern. The proposed algorithm solves a sequence of range search problems by employing a plane sweep method. The algorithm runs in O(n log n) time, where n is the number of edges in a mask pattern. Since a lower bound in time conplexity for reporting all minimum width/space violations is ${\Omega}$ (n log n), this algorithm is theoretically optimal within a constant multiplicaive factor. It requires O($n^{0.5}$) space which is very efficient in practice. Moreover, this algorithm, we believe, is easy to implement and practically fast (116.7 seconds for a rectilinear region with 250000 vertices ar VAX 8650.)

• Fashion & Textile Research Journal
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• v.9 no.2
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• pp.145-150
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• 2007

Recently, active movements are occurring to reestablish our own traditional Korean images in all levels of society. One of them is about Ordinary Hanbok. Academics and business sectors are endeavoring to develop comfortable and Korean traditional Hanbok designs and popularize them as well. Based on the facts, the study focuses on developing Ordinary Hanbok designs for women by applying Korean traditional patchwork in order to present handmade, humane senses. First of all, the backgrounds, history and preference of Ordinary Hanbok are discussed through literatures and precedent studies as study methodology. Then, the study is analyzing the formative beauty of Korean traditional patchwork that contains emotions of women in the Chosun Dynasty. After that, it shows Ordinary Hanbok designs developed for women by using checks, free style, and yeoiju patterns of the fabrics dyed with clay and Chinese ink that recently attract people in particular. The results are like followings; First, the limits that excessive transformation of Hanbok may cause the lack of traditional beauty can be covered through using a variety of images of Korean traditional patchwork. Second, diverse face configuration of patchworks has very unique geometric forms so to be easily applied to modern Ordinary Hanbok designs. Third, the sewing technique of patchworks also plays a role as a design factor as important as face configuration. Fourth, utilizing fabric pieces may result in various unplanned face configuration and help resource recycling. Fifth, it is possible to coordinate Hanbok with other ordinary clothes that people normally wear on. Sixth, using patchworks images can encourage developing more active and refined designs added with traditional beauty. Seventh, natural dying and fabrics are eco-friendly, which is good for human health and environment. Finally, more studies should be done on design development based on precedent studies about Ordinary Hanbok. Also, it is important to foster social atmosphere and circumstances where people accept wearing Ordinary Hanbok as our natural culture.

• Journal of the Korea Society of Computer and Information
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• v.15 no.11
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• pp.67-73
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• 2010

In this paper, a new face detection method that is more accurate than the conventional methods is proposed. This method utilizes a hybrid of Hausdorff distance based on the geometric similarity between the two sets of points and the LBP distance based on the distribution of local micro texture of an image. The parameters for normalization and the optimal blending factor of the two different metrics were calculated from training sample images. Popularly used face database was used to show that the proposed method is more effective and robust to the variation of the pose, illumination, and back ground than the methods based on the Hausdorff distance or LBP distance. In the particular case, the average error distance between the detected and the true face location was reduced to 47.9% of the result of LBP method, and 22.8% of the result of Hausdorff method.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.21 no.4
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• pp.267-277
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• 2009

Partial safety factors of the load, resistance, and reliability function are evaluated according to the target probability of failure on sliding mode of monolithical vertical caisson of composite breakwaters. After reliability function is formulated for sliding failure mode of caisson of composite breakwaters regarding bias of wave force, uncertainties of random variables related to loads, strengths are analyzed. Reliability analysis for the various conditions of water depth, geometric, and wave conditions is performed using Level II AFDA model for the sliding failure. Furthermore, the reliability model is also applied to the real caisson of composite breakwaters of Daesan, Dong- hae, and Pohang harbor. By comparing the required width of caisson of composite breakwater according to target probability of failure with the other results, the partial safety factors evaluated in this study are calibrated straightforwardly. Even though showing a little difference on the 1% of target probability, it may be found that the present results agree well with the other results in every other target probability of failure.

• Magazine of the Korea Concrete Institute
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• v.11 no.1
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• pp.243-254
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• 1999

This paper presents a numerical study for developing the moment magnifier method that is applicable to RC flat plates subject to combined axial compressive and floor load. For the nonlinear finite element analysis, a computer program addressing material and geometric nonlinearities was developed. The flat plates to be studied are designed in accordance with the Direct Design Method in Korean Building Code for Structural Concrete. This paper proposes the buckling force and the moment magnification factor for the flat plate under the governing load condition that is the combined vertical and subsequently applied uniaxial compressive load. The buckling force is defined with two ingredients: the buckling coefficient and the effective flexural rigidity. Parametric studies are performed to investigate variations of the buckling coefficient and the effective flexural rigidity. Based on the numerical results, this paper provides the design values of the buckling coefficient and the effective flexural rigidity, and the design procedure for the moment magnifier method.