• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.2
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• pp.231-243
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• 2016

This study presents the applicability of two-dimensional (2D) flood inundation model by applying to real irrigation reservoir failure with limited available data. The study area is Sandae Reservoir placed in Gyeongju and downstream area of it and the reservoir was failured by piping in 2013. The breach hydrograph was estimated from one-dimensional (1D) hydrodynamic model and the discharge was employed for upstream boundary of 2D flood inundation model. Topography of study area was generated by integrating digital contour map and satellite data, and Cartesian grids with 3m resolution to consider geometry of building, road and public stadium were used for 2D flood inundation analysis. The model validation was carried out by comparing predictions with field survey data including reservoir breach outflow, flood extent, flood height and arrival time, and identifying rational ranges with allowed error. In addition, the applicability of 2D model is examined using different simulation conditions involving grid size, building and roughness coefficient. This study is expected to contributed to analysis of irrigation reservoirs were at risk of a failure and setting up Emergency Action Plan (EAP) against irrigation reservoir failure.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.5
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• pp.2835-2838
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• 2013

Background: Prostate cancer features a substantial incidence and mortality burden, similarly to breast cancer, and it ranks among the top ten specific causes of death in males. Objective: To explore the situation of prostate cancer in a healthy population cohort in Eastern Nepal. Materials and Methods: This study was conducted in the Department of General Surgery at B. P. Koirala Institute of Health Sciences, Dharan, Nepal from July 2010 to June 2011. Males above 50 years visiting the Surgical Outpatient Department in BPKIHS were enrolled in the study and screening camps were organized in four Teaching District Hospitals of BPKIHS, all in Eastern Nepal. Digital rectal examination (DRE) was conducted by trained professionals after collecting blood for assessment of serum prostatic specific antigen (PSA). Trucut biopsies were performed for all individuals with abnormal PSA/DRE findings. Results: A total of 1,521 males more than 50 years of age were assessed and screened after meeting the inclusion criteria. The vast majority of individuals, 1,452 (96.2%), had PSA ${\leq}4.0$ ng/ml. Abnormal PSA (>4 ng/ml) was found in 58 (3.8%). Abnormal DRE was found in 26 (1.72%). DRE and PSA were both abnormal in 26 (1.72%) individuals. On the basis of raised PSA or abnormal DRE 58 (3.84%) individuals were subjected to digitally guided trucut biopsy. Biopsy report revealed benign prostatic hyperplasia in 47 (3.11%) and adenocarcinoma prostate in 11 (0.73%). The specificity of DRE was 66.0%with a sensitivity of 90.9% and a positive predictive value of 38.5%. The sensitivity of PSA more than 4ng/ml in detecting carcinoma prostate was 100% and the positive predictive value for serum PSA was 19.0% Conclusions: The overall cancer detection rate in this study was 0.73% and those detected were locally advanced. Larger community-based studies are highly warranted specially among high-risk groups.

• Korean Journal of Remote Sensing
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• v.34 no.2_2
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• pp.407-418
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• 2018

The frequency and risk of disasters are increasing due to environmental and social factors. In order to respond effectively to disasters that occur unexpectedly, it is very important to quickly obtain up-to-date information about target area. It is possible to intuitively judge the situation about the area through the image-map generated at high speed, so that it can cope with disaster quickly and effectively. In this study, we propose an image-map generation and visualization system from UAV images for real-time disaster monitoring. The proposed system consists of aerial segment and ground segment. In the aerial segment, the UAV system acquires the sensory data from digital camera and GPS/IMU sensor. Communication module transmits it to the ground server in real time. In the ground segment, the transmitted sensor data are processed to generate image-maps and the image-maps are visualized on the geo-portal. We conducted experiment to check the accuracy of the image-map using the system. Check points were obtained through ground survey in the data acquisition area. When calculating the difference between adjacent image maps, the relative accuracy was 1.58 m. We confirmed the absolute accuracy of the image map for the position measured from the individual image map. It is confirmed that the map is matched to the existing map with an absolute accuracy of 0.75 m. We confirmed the processing time of each step until the visualization of the image-map. When the image-map was generated with GSD 10 cm, it took 1.67 seconds to visualize. It is expected that the proposed system can be applied to real - time monitoring for disaster response.

• Journal of Environmental Impact Assessment
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• v.15 no.1
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• pp.1-12
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• 2006

Changes in the soil physical property and the topographic condition derived from agricultural activities like as farming activities, land clearance and cutting down resulted in environmental and economic problems including the outflow of nutrient from farms and the water pollution. Several theories on the soil conservation have been developed and reviewed to protect soil erosion in the regions having a high risk of erosion. This study was done using the USLE model developed by Wischmeier and Smith (1978), and model for the slope length and steepness made by Desmet and Govers (1996), and Nearing (1997) to evaluate the potential of the soil erodibility. Therefore, several results were obtained as follows. First, factors affecting the soil erosion based on the USLE could be extracted to examine the erosion potential in farms. Soil erodibility (K), slope length (L), and slope steepness (S) were used as main factors in the USLE in consideration of the soil, not by the land use or land cover. Second, the soil erodibility increased in paddy soils where it is low in soil content, and the very fine sandy loam exists. Analysis of the slope length showed that the value of a flat ground was 1, and the maximum value was 9.17 appearing on the steep mountain. Soil erodibility showed positive relationship to a slope. Third, the potential soil erodibility index (PSEI) showed that it is high in the PSEI of the areas of steep upland and orchard on the slope of mountainous region around Dokjigol mountain, Dunji mountain, and Deummit mountain. And the PSEI in the same land cover was different depending on the slope rather than on the physical properties in soil. Forth, the analysis of land suitability in soil erosion explained that study area had 3,672.35ha showing the suitable land, 390.88ha for the proper land, and 216.54ha for the unsuitable land. For unsuitable land, 8.71ha and 6.29ha were shown in fallow uplands and single cropping uplands, respectively.

• Journal of Biomedical Engineering Research
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• v.19 no.3
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• pp.251-260
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• 1998

The Holter monitoring system is a widely used noninvasive diagnostic tool for ambulatory patient who may be at risk from latent life-threatening cardiac abnormalities. In this paper, we design a high performance intelligent holter monitoring system which is characterized by the small-sized and the low-power consumption. The system hardware consists of one-chip microcontroller(68HC11E9), ECG preprocessing circuit, and flash memory card. ECG preprocessing circuit is made of ECG preamplifier with gain of 250, 500 and 1000, the bandpass filter with bandwidth of 0.05-100Hz, the auto-balancing circuit and the saturation-calibrating circuit to eliminate baseline wandering, ECG signal sampled at 240 samples/sec is converted to the digital signal. We use a linear recursive filter and preprocessing algorithm to detect the ECG parameters which are QRS complex, and Q-R-T points, ST-level, HR, QT interval. The long-term acquired ECG signals and diagnostic parameters are compressed by the MFan(Modified Fan) and the delta modulation method. To easily interface with the PC based analyzer program which is operated in DOS and Windows, the compressed data, that are compatible to FFS(flash file system) format, are stored at the flash memory card with SBF(symmetric block format).

• Journal of Dental Rehabilitation and Applied Science
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• v.28 no.1
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• pp.1-13
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• 2012

Short implants are used in parts which have anatomical structures like maxillary sinus, inferior alveolar nerve and limited alveolar height due to severe alveolar bone resorption. In these case, there are no need of additional bone augmentation so there are advantages like reduced entire treatment time, reduced patient's discomfort and protection of important anatomical structures. The aim of this study is, in implants whose length is less than 10mm, to analyze the impact of implant length, diameter, location of implant placement, presence of bone graft, presence of prosthesis splinting on survival rates and marginal bone resorption. The samples used in this study were 227 implants, less than 10mm, placed in 137 patients in Wonkwang university dental hospital implant center. From dental charts the information about implant length, diameter, location of implant placement, presence of bone graft, presence of prosthesis splinting were obtained. Emago advanced v5.6(Oral diagnostic systems, Amsterdam, The Netherlands)program was used to measure the amount of marginal bone resorption. Out of total 227 implants, resulting in 96.5 % of survival rate. There was a tendency toward higher failure rates for the maxilla and bone graft site. No significant difference in marginal bone resorption was found associated with length of implants(p>0.05) and neither with the diameter of implants. Among the risk factors examined, more failure rates of short implants can be attributed to poor bone quality in the maxilla and presence of bone graft. At implants under 10mm, length, diameter, location of implant placement, bone graft and splinting of prosthesis didn't affect marginal bone loss.

• Fire Science and Engineering
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• v.25 no.6
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• pp.136-145
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• 2011

One of a large proportion among the causes of fire is electrical factors, and of fire by electric factors, the accident which accounted for over certain percentage is electric leakage and ground fault. In order to reduce the electric leakage and ground fault, the technical guidelines on the protection of ground fault in the low-voltage electrical line (KECG 1091-2011) was amended for reflecting recent international standard, IEC 60364-4-41, and new conservation methods, which improved the reliability by recovering the facility's all-time use operation and breakdown defect, was on the rise. Accordingly, in this paper, after grasping the fire's status for last 10 years and analyzing the risk of electrical fires, and as a way to improve the electric leakage and ground fault accident which accounted for more than certain percentage, the revision of KECG 1091-2011 will be reviewed. And then, after applying to the preventive conservation methods in order to enhance the protection reliability of electric leakage and ground fault detection, the problems at issue routine inspection scheme and durable years scheme in time-scheduled conservation method are listed, along with suggestion of the problem-solving scheme, and the leakage current integrated monitoring systems and digital electric leakage devices by status monitor conservation method will be proposed.

• Journal of the Society of Naval Architects of Korea
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• v.39 no.3
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• pp.75-80
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• 2002

In these days of severe struggle for existence, the world has changed a great deal to global and digital oriented period. The enterprises try to introduce new management and production system to adapt such a change. But, if the only new technologies are applied to an enterprise without definite analysis about manufacturing, failure fellows as a logical consequence. Hence, enterprise must analyze manufacturing system definitely and needs new methodologies to mitigate risk. This study suggests that the new approach, which is systems approach for process improvement, is organized to systems analysis, systems diagnosis, and systems verification. Systems analysis analyzes manufacturing systems with object-oriented methodology-UML(Unified Modeling language) from a point of product, process, and resource view. Systems diagnosis identifies the constraints to optimize the system through scientific management or TOC(Theory of constraints). Systems verification shows the solution with virtual manufacturing technique applied to the core problem which emerged from systems diagnosis. This research shows the artifacts to improve the productivity with the above methodology applied to forming shop. UML provides the definite tool for analysis and re-usability to adapt itself to environment easily. The logical tree of TOC represents logical tool to optimize the forming shop. Discrete event simulator-QUEST suggests the tool for making a decision to verify the optimized forming shop.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.21 no.2
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• pp.87-94
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• 2010

Objectives : This study was aimed at investigating the relationship between internet game addiction and emotional and behavioral characteristics of students both in the 5th and 6th grade of elementary school and in middle school. Methods : Two elementary schools and two middle schools were chosen to participate. The students completed selfreport questionnaires designed by the authors, called the Internet Game Addiction Scale, Korean youth self-report (K-YSR). Results : Compared to previous studies, the rates of those in the obvious game addiction group were much lower in this study. We defined the upper 10% of internet game addiction scores as a high risk user group and the lower 10% as a control group. There were significant differences between the groups with respect to the the ages at which internet gaming began, the frequency of game play per week, and the average length of each game playing session. Significant associations were also found between the level of internet game addiction and the withdrawn and delinquency subscales of the K-YSR. However, the association between game addiction and the withdrawn subscale was found only in middle school students. Conclusion : The findings from this study suggested that withdrawn and delinquent behaviors could be predictors of internet game addiction. Results also suggested the importance of early childhood intervention for preventing the development of more severe psychopathology in early adolescence.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.24 no.5
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• pp.911-918
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• 2014

Over the past few years, security breaches have been consistently reported around the world. Especially, people's personal information are at risk of being breached as the firms gather and utilize the information for their marketing purposes. As an effort to revamp their data infrastructures, companies have rebuilt their system that almost every data, including the personal information, are stored within the digital database. However, this migration provides easier access to the database but it has also increased the system vulnerability. As the data can be easily exposed to the unauthorized personnel both intentionally and unintentionally, it is necessary for companies to establish a set of security protocol and operate the personal information protection system. There are two major certified security system in South Korea; PIMS from KISA and PIPL from NIA. This paper analyzes the preferences of SMEs and small business using conjoint attributes of PIMS and PIPL. The study shows that the business owners take post certification rewards as the most important factor. It also shows that the attributes that have the highest utility rates are the following; 1) KISA certification, 2) 79 points of protection counter measurements, 3) 28 items of life cycle, 3) 50 percent discount on certification fee, and 4) Reduced amount of fine for personal information leakage incident.