• 제목/요약/키워드: period classification

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Development of Site Classification System and Modification of Design Response Spectra considering Geotechnical Site Characteristics in Korea (III) - Modification of Desing Response Specra (국내 지반특성에 적합한 지반분류 방법 및 설계응답스펙트럼 개선에 대한 연구 (III) - 설계응답스펙트럼 개선방법)

  • Yoon, Jong-Ku;Kim, Dong-Soo;Bang, Eun-Seok
    • Journal of the Earthquake Engineering Society of Korea
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    • v.10 no.2 s.48
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    • pp.63-71
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    • 2006
  • In the companion paper (II, Development of Site Classification System), new size classification system based on site periods $(T_G)$ was recommended for legions of shallow bedrock depth in Korea. Despite the site classification method was improved, the response spectrum would be required to be modified by adjusting the integration interval to calculate the site coefficients because the response spectra did not match well the average spectral accelerations obtained by site response analyses in the range of long periods. In this paper, new response spectra for each site categories were determined by adjusting the integration interval of long period site coefficient $F_v\;from\;0.4{\sim}2.0\;to\;0.4{\sim}1.5$ second. It matched well the average spectral accelerations and new response spectrum, and it was also improved compared to the current she classification system.

Mortality Analysis of Surgical Neonates: A 20-year Experience by A Single Surgeon (신생아 외과 환자의 수술 후 사망률 변화에 대한 연구)

  • Lee, Eun-Joung;Choi, Kum-Ja
    • Advances in pediatric surgery
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    • v.12 no.2
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    • pp.137-146
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    • 2006
  • Pediatric surgery could establish a definitive position in the medical field on the basis of a stable patient population. Neonatal surgery, the core of pediatric surgery, requires highly skilled surgeons. However, recent advancement of prenatal diagnosis followed by intervention and decreased birth rate has resulted in a significant decrease in the neonatal surgical population and the number of surgical operations. The purpose of this study is to examine the outcome of neonatal surgeries and to propose a guide for the future surgeries. A total of 359 neonatal surgical patients operated upon at the Department of Surgery, Ewha Medical Center, during past 21 years were studied. The study period hasbeen divided into two time periods: from 1983 to 1993 and from 1994 to 2004. Analysis was based on the Clinical Classification System and mortality pattern, frequency of disorders, occurrence and cause of death, and other changes. Neonatal surgery was 6.4 % of all pediatric surgery during the total 21 year period, 9.9 % in the first period and 4.8 % in the second. Male to female ratio increased from 2.7:1 to 2.1:1. The overall mortality was 6.7 %, and there was significant decrease from 7.4 % in the first period to 6.0 % in the second. The clinical classification system (CCS) for death cases included class II 2, III 4, and IV 7 during the first period and class III 3, and IV 8 during the second, respectively. According to the mortality pattern by Hazebroek, there were 6 preventable death cases during the first period, and only one in the second, and 2 non-preventable death cases during the first period and 8 in second, respectively. Although the patients in the second period had more serious diseases, surgical mortality has been decreased in the second period, which may be the result of improved surgery methods for newborns and advanced patient care.

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A Study of the Application of Relative Location System and Minute Classification System in the DDC (DDC의 상관식 배가법 적용과 분류체계 세분화에 대한 연구)

  • Kwak, Chul-Wan
    • Journal of Korean Library and Information Science Society
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    • v.48 no.3
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    • pp.45-61
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    • 2017
  • The objective of this study is to understand the application of relative location system and minute classification system in the DDC and to identify the effect of the relative location system and minute classification system during the late of 19th century. In order to achieve the objective, four main investigation areas were chosen: relative location system, minute classification system, and DDC influence to other libraries and classification systems. First, DDC applied a relative location system revolutionarily instead of a fixed location system for arranging books on the shelves, so it opened the period of modern library classification systems. Second, it used a minute classification system, and could classify books which had minute subjects. Third, it applied form to a criterion for dividing divisions and sections, so it helped for classifying books. Fourth, it used a numerical decimal system as a classification system, then people could use it economically and practically. Last, DDC influenced modern classification system such as the Expansive Classification and the Subject Classification etc. DDC is a suitable library classification system for the needs of the times, and it is a practical classification system for each library.

A Study on the History of Mathematics Education of China (중국의수학교육사)

  • Jeon, Young-Ju
    • Journal for History of Mathematics
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    • v.24 no.2
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    • pp.91-108
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    • 2011
  • This study starts with dividing the history of mathematics education of China into four periods; Experimentation Period(the 1st period, from 1949 to 1965), Stagnancy Period(the 2nd period, from 1966 to 1976). Adjustment Period(the 3rd period, from 1977 to 1999) and Development Period(the 4th period, since 2000 ~) Through periodical classification, several causes and characteristics in mathematics education of each period are identified. And from that, this study draws implications for Korea mathematics education.

Functional Data Classification of Variable Stars

  • Park, Minjeong;Kim, Donghoh;Cho, Sinsup;Oh, Hee-Seok
    • Communications for Statistical Applications and Methods
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    • v.20 no.4
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    • pp.271-281
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    • 2013
  • This paper considers a problem of classification of variable stars based on functional data analysis. For a better understanding of galaxy structure and stellar evolution, various approaches for classification of variable stars have been studied. Several features that explain the characteristics of variable stars (such as color index, amplitude, period, and Fourier coefficients) were usually used to classify variable stars. Excluding other factors but focusing only on the curve shapes of variable stars, Deb and Singh (2009) proposed a classification procedure using multivariate principal component analysis. However, this approach is limited to accommodate some features of the light curve data that are unequally spaced in the phase domain and have some functional properties. In this paper, we propose a light curve estimation method that is suitable for functional data analysis, and provide a classification procedure for variable stars that combined the features of a light curve with existing functional data analysis methods. To evaluate its practical applicability, we apply the proposed classification procedure to the data sets of variable stars from the project STellar Astrophysics and Research on Exoplanets (STARE).

Function-Based Classification System for Public Records of Government-General of Chosun (조선총독부 기록물을 위한 기능분류체계 개발 연구)

  • 설문원
    • Journal of the Korean Society for information Management
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    • v.20 no.1
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    • pp.457-488
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    • 2003
  • Public records, produced during the period of Government-General of Chosun. are essential sources for Korean modern history research. The purpose of this study is to provide a guideline for developing function-based classification scheme for the records. This present paper begins with analyzing archival principles regarding the function-based classification. and examines the problems of current arrangement practices. Based on these analyses, it suggests a guideline for constructing a classification system and a functional thesaurus for the public records of Government-General of Chosun. This guideline also covers functional analysis process and some considerations of different classification aspects which are conceptual, verbal and notational.

Establishment of WBS·CBS-based Construction Information Classification System for Efficient Construction Cost Analysis and Prediction of High-tech Facilities (하이테크 공장의 효율적 건설 사업비 분석 및 예측을 위한 WBS·CBS 기반 건설정보 분류체계 구축)

  • Choi, Seong Hoon;Kim, Jinchul;Kwon, Soonwook
    • The Journal of the Korea Contents Association
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    • v.21 no.8
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    • pp.356-366
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    • 2021
  • The high-tech industry, a leader in the national economy, has a larger investment cost compared to general buildings, a shorter construction period, and requires continuous investment. Therefore, accurate construction cost prediction and quick decision-making are important factors for efficient cost and process management. Overseas, the construction information classification system has been standardized since 1980 and has been continuously developed, improving construction productivity by systematically collecting and utilizing project life cycle information. At domestic construction sites, attempts have been made to standardize the classification system of construction information, but it is difficult to achieve continuous standardization and systematization due to the absence of a standardization body and differences in cost and process management methods for each construction company. Particular, in the case of the high-tech industry, the standardization and systematization level of the construction information classification system for high-tech facility construction is very low due to problems such as large scale, numerous types of work, complex construction and security. Therefore, the purpose of this study is to construct a construction information classification system suitable for high-tech facility construction through collection, classification, and analysis of related project data constructed in Korea. Based on the WBS (Work Breakdown Structure) and CBS (Cost Breakdown Structure) classified and analyzed through this study, a code system through hierarchical classification was proposed, and the cost model of buildings by linking WBS and CBS was three-dimensionalized and the utilized method was presented. Through this, an information classification system based on inter-relationships can be developed beyond the one-way tree structure, which is a general construction information classification system, and effects such as shortening of construction period and cost reduction will be maximized.

Development of Site Classification System and Modification of Design Response Spectra considering Geotechnical Site Characteristics in Korea (I) - Problem Statements of the Current Seismic Design Code (국내 지반특성에 적합한 지반분류 방법 및 설계응답스펙트럼 개선에 대한 연구 (I) - 국내 내진설계기준의 문제점 분석)

  • Yoon, Jong-Ku;Kim, Dong-Soo;Bang, Eun-Seok
    • Journal of the Earthquake Engineering Society of Korea
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    • v.10 no.2 s.48
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    • pp.39-50
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    • 2006
  • Site response analyses were peformed based on equivalent linear technique using the shear wave velocity profiles of 162 sites collected around the Korean Peninsula. The she characteristics, particularly the shear wave velocities and the depth to bedrock, are compared to those in the western United States. The site coefficients of short period $(F_a)$ and the long period $(F_v)$ obtained from this study were significantly different compared to 1997 Uniform Building Code (1997 UBC). $F_a$ underestimated the motion in shot period ranges and $F_v$ overestimated the motion in mid period ranges in Korean seismic guideline. It is found that the existing Korean seismic design code were is required to be modified considering geological site conditions in Korea for the reliable estimation of sue amplification. Problems of the current seismic design code were dicussed in this paper and the development of site classification method and modification of desing response spectra were discussed in the companion papers(II-Development of Site Classification System and III-Modification of Dosing Response Specra).

Modification of Site Classification System for Amplification Factors considering Geotechnical Conditions in Korea (국내 지반 특성에 따른 합리적 증폭 계수의 결정을 위한 지반 분류 체계 개선 방안 고찰)

  • Sun, Chang-Guk;Chung, Choong-Ki;Kim, Dong-Soo
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2005.03a
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    • pp.90-101
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    • 2005
  • For the site characterization at two representative inland areas, Gyeongju and Hongsung, in Korea, in-situ seismic tests containing boring investigations and resonant column tests were performed and site-specific ground response analyses were conducted using equivalent linear as well as nonlinear scheme. The soil deposits in Korea were shallower and stiffer than those in the western US, from which the site classification system and site coefficients in Korea were derived. Most sites were categorized as site classes C and D based on the mean shear wave velocity to 30 m, Vs30 ranging between 250 and 650 m/s. Based on the acceleration response spectra determined from the site-specific analyses, the site coefficients specified in the Korean seismic design guide underestimate the ground motion in the short-period band and overestimate the ground motion in mid-period band. These differences can be explained by the differences in the bedrock depth and the soil stiffness profile between Korea and western US. The site coefficients were re-evaluated and the preliminary site classification system was introduced accounting for the local geologic conditions on the Korean peninsula.

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Suicide Mortality Across Broad Occupational Groups in Greece: A Descriptive Study

  • Alexopoulos, Evangelos C.;Kavalidou, Katerina;Messolora, Fani
    • Safety and Health at Work
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    • v.7 no.1
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    • pp.1-5
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    • 2016
  • Background: Several studies have investigated the relationship between specific occupations and suicide mortality, as suicide rates differ by profession. The aim of this study was to investigate suicide mortality ratios across broad occupational groups in Greece for both sexes in the period 2000-2009. Methods: Data of suicide deaths were retrieved from the Hellenic Statistical Authority and comparative mortality ratios were calculated. Occupational classification was based on the International Classification of Occupations (ISCO-88) and the coding for Intentional self-harm (X60-X84) was based on the international classification of diseases (ICD-10). Results: Male dominant occupations, mainly armed forces, skilled farmers and elementary workers, and female high-skilled occupations were seen as high risk groups for suicide in a period of 10 years. The age-productive group of 30-39 years in Greek male elementary workers and the 50-59 age-productive group of Greek professional women proved to have the most elevated number of suicide deaths. Conclusion: Further research is needed into the work-related stressors of occupations with high suicide mortality risk and focused suicide prevention strategies should be applied within vulnerable working age populations.