• Journal of the Institute of Convergence Signal Processing
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• v.11 no.1
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• pp.63-73
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• 2010

This paper presents the optimal design method of an overlapped ultrasonic sensor ring for reduced positional uncertainty, and its application to the obstacle detection with improved resolution. Basically, it is assumed that a set of ultrasonic sensors are installed to form a circle at regular intervals with their beams overlapped. First, exploiting the overlapped beam pattern, the positional uncertainty inherent to an ultrasonic sensor is shown to be significantly reduced. Second, for an ideal ultrasonic sensor ring of zero radius, the effective beam width is defined to represent the positional uncertainty, and the optimal number of ultrasonic sensors required for minimal effective beam width is obtained. Third, for an actual ultrasonic sensor ring of nonzero radius, the design index is defined to represent the degree of positional uncertainty, and an optimal design of an overlapped ultrasonic sensor ring consisting of commercial ultrasonic sensors with low directivity is given. Fourth, given measured distances from ultrasonic sensors, the geometric method is described to compute the obstacle position with reference to the center of a mobile robot. Finally, through experiments using our overlapped ultrasonic sensor ring prototype, the validity and performance of the proposed method is demonstrated.

• Proceedings of the Korea Contents Association Conference
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• 2014.11a
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• pp.419-420
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• 2014

본 연구는 대장암 환자들의 암으로 진단받은 당시의 생활습관 실태를 암 병력이 없는 일반 성인들과 비교해봄으로써 대장암의 발생에 영향을 미치는 위험요인을 규명하고자 실시되었다. 연구 설계: 대장암 환자의 생활습관 실태를 파악하고, 대장암 발생에 영향을 미치는 인자를 확인하기 위하여 대장암 환자와 암 진단을 받지 않은 건강인을 대상으로 시도된 후향적 비교 조사연구(retrospective comparison survey study). 연구 대상자는 2011년 10월부터 2012년 8월까지 대장암으로 진단된지 1년 이내로 J대학교병원 내의 암전문연구센터에 내원한 대장암 환자 107명과 동 시기에 동 병원을 방문한 암환자 아닌 환자의 보호자 중 암진단을 받지 않은 일반 성인을 대상으로 빈도 짝찟기를 통해 연령, 성별 및 배우자 상태 등이 동질한 124명이었다. 연구 도구는 김화영(2011)의 생활습관 측정도구(Content Validity Index [CVI], Mean expert proportion=0.98) 를 저자의 승인 하에 사용하였으며, 관련문헌을 참조하여 수정 보완한 후 식습관, 음주 및 흡연 습관, 휴식 및 활동 습관, 스트레스 관리 및 정기검진습관 등의 5개 하위영역으로 측정하였다. 연구결과 인스턴트식품 섭취여부, 스트레스 해소정도, 육류 익힌정도(살짝 익힘/탈정도로 익힘) 및 평소 주로 먹는 음식(채식/육식 여부)이 대장암 발생에 유의한 영향을 미치는 요인으로 나타났다. 대장암환자군과 건강인군의 생활습관을 비교한 본 연구의 결과를 토대로 하여, 평소 식습관에서 인스턴트식품 등의 가공식품의 섭취를 줄이고, 스트레스가 발생(인지)될 때 이를 효과적으로 조절할 수 있도록 하며, 육류섭취 시 살짝 익혀서 먹는 습관이 실천되어야 할 것이다. 또한 평소에 육류 섭취를 줄이고 섬유질이 많은 채식 위주로 식사하도록 권장해야 할 것이다.

• The Korean Journal of Applied Statistics
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• v.25 no.1
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• pp.29-43
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• 2012

Financial data such as stock index returns and exchange rates have the properties of heavy tail and asymmetry compared to normal distribution. When we estimate VaR using the GARCH model (with the conditional return distribution of normal) it shows the tendency of the lower estimation and clustering in the losses over the estimated VaR. In this paper, we argue that this problem can be resolved through the adaptation of the unbounded Johnson distribution as that of the condition return. We also compare this model with the GARCH with the conditional return distribution of normal and student-t. Using the losses exceed the ex-ante VaR, estimates, we check the validity of the GARCH models through the failure proportion test and the clustering test. We nd that the GARCH model with conditional return distribution of unbounded Johnson provides an appropriate estimation of the VaR and does not occur the clustering of violations.

• Journal of Preventive Medicine and Public Health
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• v.42 no.2
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• pp.130-134
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• 2009

Objectives : A method of estimation using 8 populationbased cancer registries databases in Korea(KRCR DB) has been introduced as another strategy for validly estimating the national cancer incidence(NCI) in Korea. The purpose of this study was to evaluate the validity of this method with using the 7 KRCR DBs, excluding Seoul covering 21% of the total population of Korea. Methods : We designed the study method(NCSE_7) as same as the estimating method with using 8 KRCR DBs (NCSE_8) in order to ensure maximal comparability. We defined the expected number of cancer cases in each registry as the number of observed cases and then we added the weighted observed cases according to gender, age and the proportion of the population covered by each registry for the population of the seven regions and the population of all areas, with excluding these seven regions. From the expected number of total cancer incidents, the estimated NCI was calculated by dividing the expected number of cancer cases by the number of the total population. The standard error(SE) of the estimated incidence was also taken from the expected number of total cancer incidents. Results : Compared with the results of the NCSE_8, the overall age-standardized rates(ASR) in men and women became over-estimated and under-estimated, respectively. Primary sites that showed statistically significant differences were the colo-rectum, prostate, breast and thyroid. The index of death certificate only(DCO)and microscopically verified(MV)% indicating levels of data quality were decreased, especially for the brain in DCO% and kidney in the MV%. Conclusions : The database of Seoul regional cancer registry has a key role for the method to estimate the valid nationwide cancer statistics in Korea with using the population-based cancer registries databases.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.28 no.2
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• pp.106-111
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• 2017

Background and Objectives : The purpose of this study was to investigate the criterion-related concurrent validity of two standardized auditory-perceptual assessments and the Acoustic Voice Quality Index (AVQI) for measuring dysphonia severity in patients with vocal cord paralysis (VCP). Materials and Methods : Total 210 patients with VCP and 236 normal voice subjects were asked to sustain the vowel [a:] and to read aloud the Korean text "Walk". A 2 second mid-vowel portion of the sustained vowel and two sentences (with 26 syllables) were recorded. And then voice samples were edited, concatenated, and analyzed according to Praat script. Two standardized auditory-perceptual assessment (GRBAS and CAPE-V) were performed by three raters. Results : The VCP group showed higher AVQI, Grade (G) and Overall Severity (OS) values than normal voice group. And the correlation among AVQI, G, and OS ranged from 0.904 to 0.926. In ROC curve analysis, cutoff values of AVQI, G, and OS were <3.79, <0.00, and <30.00, respectively, and the AUC of each analysis was over .89. Conclusion : AVQI and auditory evaluation can improve the early screening ability of VCP voice and help to establish effective diagnosis and treatment plan for VCP-related dysphonia.

• Journal of the Korean Society for Library and Information Science
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• v.33 no.1
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• pp.87-111
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• 1999

This article investigates the functions, needs, and developments of the MARC format for classification data. and recommends the development for the KORMARC format for classification data. It ae analyzes the record structure, content designation and the content of it mainly based on USMARC format. Structure and content designation are almost same with those of the bibliographic and authority formats. The data fields divided into functional blocks based on their functions. Record contents of the data in the fixed-length fields include more elements on the classification numbers, including type of number, classification validity, standard or optional number, synthesized number. Variable fields can be grouped into several blocks, inducing those for numbers and codes: for classification numbers and terms; for references and tracings; for notes fields: for index terms fields, and for number building fields. Data in each fields of this format have the same contents with those in other related fields as soon as possible. This article analyzes the content in each data fields in detail.

• Asian Journal of Innovation and Policy
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• v.9 no.2
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• pp.223-239
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• 2020

It is important for urban planners and policy makers to understand complex, diverse urban demands and social structure, but this is not easy due to lack of data that represents the dynamics of residents at micro-geographical level. This paper explores how to create population data at at a micro-level by allocating population data to building. It attempted to allocate population data stored in a grid layer (100 meters by 100 meters) into a building footprint layer that represents the appearance of physical buildings. For the allocation, this paper describes a systemic approach that classifies grid cells into five prototypical patterns based on the composition of residential building types in a grid cell. This approach enhances allocation accuracy by accommodating heterogeneity of urban space rather than relying on the assumption of uniform spatial homogeneity of populations within an aerial unit. Unlike the methods that disaggregate population data to the parcel, this approach is more applicable to Asian cities where large multifamily residential parcels are common. However, it should be noted that this paper does not demonstrate the validity of the allocated population since there is a lack of the actual data available to be compared with the current estimated population. In the case of water and electricity, the data is already attached to an individual address, and hence, it can be considered to the purpose of the validation for the allocation. By doing so, it will be possible to identify innovative methods that create a population distribution dataset representing the comprehensive and dynamic nature of the population at the micro geographical level.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.55 no.10
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• pp.426-432
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• 2006

This paper describes the concepts of Static Line Rating (SLR) and Dynamic Line Rating (DLR) and the computational methods to demonstrate them. Calculation of the line capacity needs the heat balance equation which is also used for computing the reduced tension in terms of line aging. SLR is calculated with the data from the worst condition of weather throughout the year. Even now, the utilization ratio is obtained from this SLR data in Korea. DLR is the improved method compared to SLR. A process for DLR reveals not only improved line ratings but also more accurate allowed line ratings based on line aging and real time conditions of weather. In order to reflect overhead transmission line aging in DLR, this paper proposes the method that considers the amount of decreased tension since the lines have been installed. Therefore, the continuous allowed temperature for remaining life time is newly acquired. In order to forecast DLR, this paper uses weather forecast models, and applies the concept of Thermal Overload Risk Probability (TORP). Then, the new concept of Dynamic Utilization Ratio (DUR) is defined, replacing Static Utilization Ratio (SUR). For the case study, the two main transmission lines which are responsible for the north bound power flow in the Seoul metropolitan area are chosen for computing line rating and utilization ratio. And then line rating and utilization ratio are analyzed for each transmission line, so that comparison of the present and estimated utilization ratios becomes available. Finally, this paper proves the validity of predictive DUR as the objective index, with simulations of emergency state caused by system outages, overload and so on.

• Journal of The Korean Digital Architecture Interior Association
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• v.12 no.4
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• pp.49-57
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• 2012

With regard to the culture in cities this study aims to essential understanding and systematic approach to the culture. The "2011 Seoul Survey"report has been used to find out causality among the related variables. In the first place 'satisfaction of cultural condition' was operationally selected as a dependent variable for regression. For the purpose of controlling confounding factors for ceteris paribus effect correlation analysis was done between the dependent variable and all other variables respectively, which resulted in two groups of variables: group (1) - 6 variables of very significant correlations(p-value<0.01) and (2) - the other 6 variables of significant correlations(p-value<0.05). Then hierarchical regression was adopted to these 2 groups to analyse $R^2$ increment, statistical significance of independent variables, and multicollinearity(VIF; variance inflation factor). At last a regression model specified by group (1) as independent variables(they are 'social trust', 'satisfaction of walking condition', 'happiness index', 'preparation against old age', 'satisfaction of traffic condition' and 'hours for internet') shows that only 'social trust' variable has statistically significant and substantially strong effect on 'satisfaction of cultural condition.' This finding should be accepted on the following understanding; (1) urban culture has a collective attribute formed between people and society, (2) culture is somewhat telling and hearing stories and the confidence between tellers and hearers is essential in the mutual response and (3) stimulus is received by relationship in company with sense, emotion, thinking and action. In spite of restrictive external validity this finding can be used as a direction for promoting culture and a basis for related policy choice in cities.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.33 no.3
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• pp.103-113
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• 2015

This study is an evaluation index development research based on Gyeongju Historic Heritage Sites to identify the attractive Properties of Gyeongju, which decided to competitiveness of the historical city. We got the export Indicator candidate groups by the literature reviews and UNESCO, ICOMOS, and 49 Indicator candidate groups had been selected. In the end, we chose 42 attraction indexes in charm of the cultural heritage side, Cultural heritage tourism resources Side, Restraining force Heritage tourism Side three aspects based on the analysis of Importance(M), Standard deviation(SD), Content Validity Ratio(CVR), Agreement, convergence by using Delphi Technique. We can determine these indicators will be useful basic information, for improving the city's historic attractions. In the future, used these indicators as a basis for Attractions effectiveness evaluation of Gyeongju, Through which the attractions of Gyeongju can be re-recognized.