• Journal of Korean Tunnelling and Underground Space Association
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• v.16 no.1
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• pp.105-115
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• 2014

A numerical analysis on the smoke behavior and evacuee safety has been performed with computational fluid dynamics. The purpose of this study is to build computational processes for an evacuation and prevention of a fire disaster of a 3 km-length tunnel in Korea. To save computational cost, 1.5 km of the tunnel that can include a few cross-passing tunnels is considered. We are going to assess the fire safety in a road tunnel according to the smoke level, which consists of the smoke density and the height from the floor. The smoke density is obtained in detail from three-dimensional unsteady CFD analysis. To obtain proper temperature distributions on the tunnel wall, one-dimensional conduction equation is considered instead of an adiabatic wall boundary or a constant heat flux. The tunnel considered in this study equips the cross passing tunnels for evacuees every 250 m. The distance is critical in both safety and economy. The more cross passing tunnels, the more safe but the more expensive. Three different jet fan operations can be considered in this study; under- and over-critical velocities for normal traffic condition and 0-velocoty operation for the traffic congestion. The SE (smoke environment) level maps show a smoke environment and an evacuating behavior every moment.

• Journal of The Korean Association For Science Education
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• v.22 no.2
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• pp.398-409
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• 2002

The purpose of this study was to investigate the validity, reliability and practicality of a concept map as an assessment tool in the context of biology concept learning. Forty undergraduate students participated in concept mapping, and the maps were scored by preservice science teachers, using one of three different scoring methods, that is, concept map scoring methods developed by Burry-Stock, Novak & Gowin and McClure & Bell. Two scorers were assigned to each scoring method. As far as the validity of the assessment methods was concerned, two of the three methods were found to be very valid, while Burry-Stock's scoring method was shown little valid. As far as the internal consistency of the methods was concerned, considerably high consistencies were shown between every pair of scorers, judging from high correlation coefficients between the pair of scorers for each scoring method. It took from 1.13 minutes to 3.70 minutes to assess a map at the average. It showed that concept mapping could be used in school classrooms with the limited resources of time and people. These findings suggest that the concept mapping can be an appropriate tool for assessing biology concept understandings.

• Radiation Oncology Journal
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• v.27 no.2
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• pp.91-102
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• 2009

Purpose: To compare the accuracy and efficacy of EDR2 film, a 2D ionization chamber array (MatriXX) and an amorphous silicon electronic portal imaging device (EPID) in the pre-treatment QA of IMRT. Materials and Methods: Fluence patterns, shaped as a wedge with 10 steps (segments) by a multi-leaf collimator (MLC), of reference and test IMRT fields were measured using EDR2 film, the MatriXX, and EPID. Test fields were designed to simulate leaf positioning errors. The absolute dose at a point in each step of the reference fields was measured in a water phantom with an ionization chamber and was compared to the dose obtained with the use of EDR2 film, the MatriXX and EPID. For qualitative analysis, all measured fluence patterns of both reference and test fields were compared with calculated dose maps from a radiation treatment planning system (Pinnacle, Philips, USA) using profiles and $\gamma$ evaluation with 3%/3 mm and 2%/2 mm criteria. By measurement of the time to perform QA, we compared the workload of EDR2 film, the MatriXX and EPID. Results: The percent absolute dose difference between the measured and ionization chamber dose was within 1% for the EPID, 2% for the MatriXX and 3% for EDR2 film. The percentage of pixels with $\gamma$%>1 for the 3%/3 mm and 2%/2 mm criteria was within 2% for use of both EDR2 film and the EPID. However, differences for the use of the MatriXX were seen with a maximum difference as great as 5.94% with the 2%/2 mm criteria. For the test fields, EDR2 film and EPID could detect leaf-positioning errors on the order of -3 mm and -2 mm, respectively. However it was difficult to differentiate leaf-positioning errors with the MatriXX due to its poor resolution. The approximate time to perform QA was 110 minutes for the use of EDR2 film, 80 minutes for the use of the MatriXX and approximately 55 minutes for the use of the EPID. Conclusion: This study has evaluated the accuracy and efficacy of EDR2 film, the MatriXX and EPID in the pre-treatment verification of IMRT. EDR2 film and the EPID showed better performance for accuracy, while the use of the MatriXX significantly reduced measurement and analysis times. We propose practical and useful methods to establish an effective QA system in a clinical environment.

• The Journal of the Korea Contents Association
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• v.20 no.10
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• pp.190-198
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• 2020

The development in smartphone technology has brought convenience to the life of the mankind, but an excessive use of smartphones sometimes causes various accidents. This research tried to propose an application service 'Smombie Safe Go' UI(User Interface) that allows the prevention of such accident while using smartphones when walking. For this, after research and user observations, produced walker journey maps and derived necessary main functions needed for safety, and the result showed that transparent interface, obstacle location alert, warning of dangers functions were necessary. To make the contents of the service more detailed, hazardous situations faced during smartphone use when walking were classified into 3 situations : 1. Obstacle appearing in front, 2. traffic lights on crosswalks 3. No traffic lights on crosswalks. Scenarios by hazardous situation were written, and the flow and UI of the app service that warns its users in each situation of hazards were designed. it is predicted that 'Smombie Safe Go' may be possible to be utilized as an app service that provides a safe walking experience for not only regular pedestrians but also the blind population.

• Journal of Biosystems Engineering
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• v.33 no.5
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• pp.362-369
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• 2008

There is developing interest in precision agriculture in Korea, despite the fact that typical Korean fields are less than 1 ha in size. Describing within-field variability in typical Korean production settings is a fundamental first step toward determining the size of management zones and the inter-relationships between limiting factors, for establishment of site-specific management strategies. Measurements of rice (Oriza Sativa L) yield, chlorophyll content, and soil properties were obtained in a small (100-m by 30-m) Korean rice paddy field. Yield data were manually collected on 10-m by 5-m grids (180 samples with 3 samples in each of 60 grid cells) and chlorophyll content was measured using a Minolta SPAD 502 in 2-m by 2-m grids. Soil samples were collected at 275 points to compare results from sampling at different scales. Ten soil properties important for rice production in Korea were determined through laboratory analyses. Variogram analysis and point kriging with and without median polishing were conducted to determine the variability of the measured parameters. Influence of variogram model selection and other parameters on the interpretation of the data was investigated. For many of the data, maximum values were greater than double the minimum values, indicating considerable spatial variability in the small paddy field, and large-scale spatial trends were present. When variograms were fit to the original data, the limits of spatial dependency for rice yield and SP AD reading were 11.5 m and 6.5 m, respectively, and after detrending the limits were reduced to 7.4 m and 3.9 m. The range of spatial dependency for soil properties was variable, with several having ranges as short as 2 m and others having ranges greater than 30 m. Kriged maps of the variables clearly showed the presence of both large-scale (trend) variability and small-scale variability in this small field where it would be reasonable to expect uniformity. These findings indicate the potential for applying the principles and technology of precision agriculture for Korean paddy fields. Additional research is needed to confirm the results with data from other fields and crops.d similar tendency with the result for the frequency less than 20 Hz, but the width of change was reduced highly.

• Proceedings of the KSRS Conference
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• 2006.03a
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• pp.178-186
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• 2006

기상 수치예보는 (Numerical Weather Pridiction, NWP)는 바람, 기온, 등과 같은 기상요소의 시간 변화를 나타내는 물리방정식을 컴퓨터로 풀어 미래의 대기 상태를 예상하는 과학적인 방법으로 지구를 상세한 격자 2진부호(GRIdded Binary, 이하 GRIB)로 나누어 그 격자점에서의 값으로 대기 상태를 나타낸다. 지구 각지에서의 각종 관측자료를 기초로 격자점상의 현재값을 구한다. 대용량의 격자데이터는 이진형태이어서 컴퓨터, 서버 저장장치에서 동일형태 데이터로 존재한다. 우리나라 최초의 저궤도 관측 위성인 다목적 실용위성 KOMPSAT-1호(이하, 아리랑 위성1호)는 전자광학카메라(Electro Optical Camera, EOC)를 탑재하여 1999년 12월 21일에 발사된 이후 2006년 1월 현재까지 6여년간 성공적으로 임무를 수행, 7049여회의 영상을 획득하여 국가적으로 귀중한 자료로 활용하고 있다. 아리랑 위성1호는 일일 2-3회 EOC영상을 획득하고 있으며, 임무계획(Mission Planning)은 MP(Mission Planner)가 사용자로부터 자료를 수집하여 임무분석 및 계획 서브시스템(MAPS)에 의해 계산되어진 위성의 제도예측 데이터에 촬영하고자하는 목표지점 좌표를 입력하여 자동명령생성기(KSCG)에 의해 계산된 촬영 경사각도(Tilt)값을 위성에 전송하여 목표지역의 영상을 획득하게 된다. 위성영상 획득에 있어 고가의 위성을 운영하면서 기상의 상태를 정확히 예측하여 실패없이 유효한 영상을 획득하는 것이 무엇보다 중요하다. 본 논문에서는 효율적인 위성임무계획을 위한 기상수치예보 자료를 분석하여 앞으로 발사하게 될 고해상 카메라 탑제위성인 아리랑 위성2호와 3호에 적용하고자 한다. the sufficient excess reactivity to override this poisoning must be inserted, or its concentration is decreased sufficiently when its temporary shutdown is required. As ratter of fact, these have an important influence not only on reactor safety but also on economic aspect in operation. Considering these points in this study, the shutdown process was cptimized using the Pontryagin's maximum principle so that the shutdown mirth[d was improved as to restart the reactor to its fulpower at any time, but the xenon concentration did not excess the constrained allowable value during and after shutdown, at the same time all the control actions were completed within minimum time from beginning of the shutdown.및 12.36%, $101{\sim}200$일의 경우 12.78% 및 12.44%, 201일 이상의 경우 13.17% 및 11.30%로 201일 이상의 유기의 경우에만 대조구와 삭제 구간에 유의적인(p<0.05) 차이를 나타내었다.는 담수(淡水)에서 10%o의 해수(海水)

• Journal of the Korean Association of Geographic Information Studies
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• v.10 no.1
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• pp.35-46
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• 2007

In the study digital imagery was used to examine asphalt concrete pavements. With digitally mastered-image information that was filmed with a video camera fixed on a car travelling on road at a consistent speed, a road surface management system that can gain road surface information (Crack, Rutting, IRI) was developed using an object-oriented language "Delphi". This system was designed to improve visualized effects by animations and graphs. After analyzing the accuracy of 3-D coordinates of road surfaces that were decided using multiple image orientation and bundle adjustment method, the average of standard errors turned out to be 0.0427m in the X direction, 0.0527m in the Y direction and 0.1539m in the Z direction. As a result, it was found to be good enough to be put to practical use for maps drawn on scales below 1/1000, which are currently producted and used in our country, and GIS data. According to the analysis of the accuracy in crack width on 12 spots using a digital video camera, the standard error was found to be ${\pm}0.256mm$, which is considered as high precision. In order to get information on rutting, the physically measured cross sections of 4 spots were compared with cross sections generated from digital images. Even though a maximum error turned out to be 10.88mm, its practicality is found in work efficiency.

• Journal of Embryo Transfer
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• v.19 no.3
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• pp.291-299
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• 2004

Characterization of quantitative trait loci (QTL) was investigated in the experimental cross population between Berkshire and Yorkshire breed. A total of 512 F$_2$ offspring from 65 matting of F$_1$ parents were phenotyped the carcass traits included average daily gain (ADG), average backfat thickness (ABF), tenth rip backfat thickness (TRF), loin eye area (LEA), and last rip backfat thickness (LRF). All animals were genotyped for 125 markers across the genome. Marker linkage maps were derived and used in QTL analysis based on line cross least squares regression interval mapping. A decision tree to identify QTL with imprinting effects was developed based on tests against the Mendelian mode of QTL expression. To set the evidence of QTL presence, empirical significance thresholds were derived at chromosome-wise and genome-wise levels using specialized permutation strategies. Significance thresholds derived by the permutation test were validated in the data set based on simulation of a pedigree and data structure similar to the Berkshire-Yorkshire population. Genome scan revealed significant evidences for 13 imprinted QTLs affecting growth and body compositions of which nine were identified to be QTL with paternally expressed inheritance mode. Four of QTLs in the loin eye area (LEA), and tenth rip backfat thickness (TRF), a maternally expressed QTL were found on chromosome 10 and 12. These results support the useful statistical models to analyse the imprinting far the QTLs related carcass trait.

• Journal of the Korean Association of Geographic Information Studies
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• v.16 no.1
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• pp.1-14
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• 2013

The world largest land reclamation project in the name of Saemangeum(Ariul) from 1991 to the present has been implementing in a part of the west coast of Korea. In the Saemangeum reclamation project, the large-scale project cost is used for the landfill reclamation. A number of landfill reclamation methods have been studied in order to reduce the large-scale cost of the Saemangeum project under construction. There are many studies related to the on-site real-time monitoring with mobile systems for operating a wide range of landfill. In order to apply the work method for efficient cost-savings in the landfill operations to the Samangeum project, this paper develops a mobile management system that is composed of a mobile interface module, a data server module for data transmission and storage, and an analysis server module to analyze the input data and derive the results. The mobile system is designed by analysing user's and system requirements, functional interactions, and data flow using unified modeling language(UML). The user interface is developed for the on-site real-time monitoring through the status and related attributes of land reclamation by using the digital maps of the Samangeum coverage via mobile devices. Finally, a mobile management system would be developed that can provide a 3D GIS service based on the Dry Internal Project Site Digging Reclamation Method(DIPSDRM).

• Journal of Biomedical Engineering Research
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• v.25 no.5
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• pp.323-328
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• 2004

The development of group-specific tissue probability maps (TPM) provides a priori knowledge for better result of cerebral tissue classification with regard to the inter-ethnic differences of inter-subject variability. We present sequential procedures of group-specific TPM and evaluate the age effects in the structural differences of TPM. We investigated 100 healthy volunteers with high resolution MRI scalming. The subjects were classified into young (60, 25.92+4.58) and old groups (40, 58.83${\pm}$8.10) according to the age. To avoid any bias from random selected single subject and improve registration robustness, average atlas as target for TPM was constructed from skull-stripped whole data using linear and nonlinear registration of AIR. Each subject was segmented into binary images of gray matter, white matter, and cerebrospinal fluid using fuzzy clustering and normalized into the space of average atlas. The probability images were the means of these binary images, and contained values in the range of zero to one. A TPM of a given tissue is a spatial probability distribution representing a certain subject population. In the spatial distribution of tissue probability according to the threshold of probability, the old group exhibited enlarged ventricles and overall GM atrophy as age-specific changes, compared to the young group. Our results are generally consistent with the few published studies on age differences in the brain morphology. The more similar the morphology of the subject is to the average of the population represented by the TPM, the better the entire classification procedure should work. Therefore, we suggest that group-specific TPM should be used as a priori information for the cerebral tissue classification.