• Title/Summary/Keyword: period classification

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A Proposition of Site Coefficients and Site Classification System for Design Ground Motions at Inland of the Korean Peninsula (국내 내륙의 설계 지반 운동 결정을 위한 지반 증폭 계수 및 지반 분류 체계 제안)

  • Sun Chang-Guk;Chung Choong-Ki;Kim Dong-Soo
    • Journal of the Korean Geotechnical Society
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    • v.21 no.6
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    • pp.101-115
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    • 2005
  • For the site characterization at two inland areas, Gyeongju and Hongsung, which represent geomorphic and geologic characteristics of inland region in Korea, in-situ seismic tests containing borehole drilling investigations and resonant column tests were peformed and site-specific seismic response analyses were conducted using equivalent linear as well as nonlinear scheme. The soil deposits in Korea were shallower and stiffer than those in western US, from which the site coefficients and site classification system in Korea were derived. Most sites were categorized as site classes C and D based on the mean shear wave velocity $(V_s)$ of the upper 30 m $(V_s30)$, ranging between 250 and 650 m/s. According to the acceleration response spectra determined from the site response analyses, the site coefficients specified in the current 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, $F_a$ for short-period and $F_v$ for mid-period, were re-evaluated and the site classification system, in which sites C and D were subdivided according to $V_s20,\;V_s15,\;and\;V_s10$ together with the existing $V_s30$ was introduced accounting for the local geologic conditions at inland region of the Korean peninsula. The proposed site classification system in this paper is still rudimentary and requires modification.

A Study on Job Rotation in Civil Service (공무원 순환보직에 관한 연구)

  • Kim, Kwang-ho
    • KDI Journal of Economic Policy
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    • v.30 no.2
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    • pp.61-97
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    • 2008
  • This paper aims at analyzing the practice of job rotation in the Korean government and putting forward policy suggestions. The Korean government is often accused of low capacity and weak competitiveness, which mainly result from the low expertise of public officials. Considering the high quality of human resources flowing into the public sector in Korea, solutions should be found from the structure of the system. This paper regards frequent position changes due to excessive job rotation as a key factor undermining the accumulation of expertise and conducts in-depth analyses. The current practice of frequent rotation shows that the average tenure period of government officials at director level and above is only about one year, far shorter than those in major developed countries, which causes many problems such as low efficiency, lack of accountability and policy consistency, and low opportunity for accumulating expertise. Simple models are set up to analyze job rotation and other alternative personnel management systems. Analyses find that it would be desirable to have each individual experience various positions during the initial rotation period to find his/her own aptitude, and then accumulate expertise by settling in at a certain specialized field for a prolonged period of time based on the revealed aptitude in mid and high positions. This turns out to be in line with the structure of the Career Development Program which is being introduced. The model-based analysis of this paper distinguishes this study from preceding ones conducted in the traditional framework of personnel management study. Practical measures to mitigate the problems of frequent job rotation include rotating within the area of specialty, narrowing the scope of transfer, and reinforcing the minimum tenure period. However, since the current frequent rotation is fundamentally attributable to the rank system based on seniority, the present civil service classification system needs to be converted into a position classification system in the long run.

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The construction classification of coastal castles in the early Joseon period and the background on their relocation (조선전기 남동부 연해읍성의 축조유형 구분과 이건배경)

  • Kwon, Soon-Kang;Lee, Ho-Yeol
    • Journal of architectural history
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    • v.24 no.4
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    • pp.29-44
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    • 2015
  • Coastal eupseongs, which are mainly built in the period of late Goryeo and early Joseon period, are essential materials in studying the history of Joseon period eupseongs. The purpose of this study is to connect the annexation of local districts with the relocation of local government office, so as to categorize the types of coastal-eupseongs and examine the background of their constructions and relocations. Coastal eupseongs are mainly divided into 'maintenance type' and 'Mergence type' according to the annexation of local districts, and maintenance type is broken down into fortress type and non-fortress type in accordance with the existence of old eupseongs(fortresses). Coastal eupseongs can also be categorized into 'application type' and 'relocation type' depending on whether ex-local government offices were reutilized or relocated. Maintenance type is 'fortress-application type'(Gimhae Gosung Old Ulsan-eupseong), 'non-fortress-application type'(New Ulsan-eupseong), 'fortress-relocation type'(Dongrae Kijang Geojegohyunseong Ulsan(Jwabyeongyoung)-eupseong), 'non-fortress-relocation type'(Sacheon Hadong Jinhae-eupseong Geojesadeongseong) are differentiated by type. Mergence type is divided into 'Merger of Villages after Castle Relocation Type(Changwon Namhae Gonyang-eupseong)', 'Merger of Villages before Castle Relacation Type(Ungcheon-eupseong)'. Coastal-eupseongs are moved to other places in need of more affluent water supply(Gimhae Gijang-eupseong) and wider usable area(Namhae Gohyunseong-eupseong). Eupseongs were enlarged owing to the population growth, caused by annexations of local districts.(Ungcheon-eupseong) 'Seonso'(navy yard) is a unique feature which cannot be seen in inland eupseongs.

Site Classification and Design Response Spectra for Seismic Code Provisions - (II) Proposal (내진설계기준의 지반분류체계 및 설계응답스펙트럼 개선을 위한 연구 - (II) 제안)

  • Cho, Hyung Ik;Satish, Manandhar;Kim, Dong Soo
    • Journal of the Earthquake Engineering Society of Korea
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    • v.20 no.4
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    • pp.245-256
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    • 2016
  • In the companion paper (I - Database and Site Response Analyses), site-specific response analyses were performed at more than 300 domestic sites. In this study, a new site classification system and design response spectra are proposed using results of the site-specific response analyses. Depth to bedrock (H) and average shear wave velocity of soil above the bedrock ($V_{S,Soil}$) were adopted as parameters to classify the sites into sub-categories because these two factors mostly affect site amplification, especially for shallow bedrock region. The 20 m of depth to bedrock was selected as the initial parameter for site classification based on the trend of site coefficients obtained from the site-specific response analyses. The sites having less than 20 m of depth to bedrock (H1 sites) are sub-divided into two site classes using 260 m/s of $V_{S,Soil}$ while the sites having greater than 20 m of depth to bedrock (H2 sites) are sub-divided into two site classes at $V_{S,Soil}$ equal to 180 m/s. The integration interval of 0.4 ~ 1.5 sec period range was adopted to calculate the long-period site coefficients ($F_v$) for reflecting the amplification characteristics of Korean geological condition. In addition, the frequency distribution of depth to bedrock reported for Korean sites was also considered in calculating the site coefficients for H2 sites to incorporate sites having greater than 30 m of depth to bedrock. The relationships between the site coefficients and rock shaking intensity were proposed and then subsequently compared with the site coefficients of similar site classes suggested in other codes.

Construction of the Digital Archive System from the Records of Westerners Who Stayed in Korea during the Enlightenment Period of Chosun (개화기 조선 체류 서양인 기록물의 디지털 아카이브 시스템 구축)

  • Chung, Heesun;Kim, Heesoon;Song, Hyun-Sook;Lee, Myeong-Hee
    • Journal of the Korean BIBLIA Society for library and Information Science
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    • v.27 no.4
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    • pp.229-249
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    • 2016
  • This study was conducted to create a digital archive for local cultural contents compiled from the records of westerners who stayed in Korea during the Enlightenment Period of Chosun. The compiled information were gathered from 22 records, and 10 main subjects, 40 sub-subjects and 239 mini-subjects were derived through the subject classification scheme. Item analysis was conducted through 38 metadata and input data types were classified and databased in Excel. Finally, a web-based digital archiving system was developed for searching and providing information through various access points. Suggestions for future research were made to expand archive contents through continuous excavation of westerners' records, to build an integrated information system of Korean digital archives incorporating individual archive systems, to develop standardization of classification schemes and a multidimensional classification system considering facet structure in cultural heritage areas, to keep consistency of contents through standardization of metadata format, and to build ontology using semantic search functions and data mining functions.

Application of Normality Test and Classification of Process Capability Index (공정능력지수의 유형화 및 정규성 검정의 응용)

  • Choe, Seong-Un
    • Proceedings of the Safety Management and Science Conference
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    • 2011.11a
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    • pp.551-556
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    • 2011
  • This research presents an implementation strategy of Process Capability Index (PCI) according to the types of process characteristics. The types of process feature are classified as four perspectives of variation range, time period, error position, and process stage. The paper examines short-term or long-term PCI, within or between variation, position of precision or accuracy, and inclusion of measurement or calibration stage. Moreover, the study proposes normality test of unilateral PCI.

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The Damage Classification by Periodicity Detection of Ultrasonic Wave Signal to Occur at the Tire (타이어에서 발생하는 초음파 신호의 주기성 검출에 의한 손상 분별)

  • Oh, Young-Dal;Kang, Dae-Soo
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.10 no.6
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    • pp.107-111
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    • 2010
  • The damage of tire by damage material classification method is researched as used ultrasonic wave signal to occur at a tire during vehicle driving. Auto-correlation function after having passed through an envelope detecting preprocess is used for detecting periodicity because of occurring periodic ultrasonic waves signal with tire revolution. One revolution cycle time of a damaged tire and period that calculated auto-correlation function appeared equally in experiment. The result that can classification whether or not there was a tire damage is established.

A Study on the Periodization in the History of Korean dwellings during the age of prehistory and the ancient Kingdomes (한국(韓國) 선사시대(先史時代) 및 삼국시대(三國時代) 주거사(住居史)의 시대구분(時代區分)에 관한 재고(再考))

  • Kang, Young-Hwan
    • Journal of architectural history
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    • v.5 no.2 s.10
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    • pp.9-24
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    • 1996
  • Owing to the energitic studies of the leading shcolars, some paradigmatic theories on the history of Korean dwellings have been suggested. They constructed periodization of their own and defined characteristics of each period with very limited historical materials. However the new historical materials have been discovered in the neighboring academic fields, which require to review the existing theories. This study aims at restructuring periodization in the history of Korean dwellings during the age of The prehistory and The ancient Kingdomes. Through the study, the existing theories on the same period are revived and evaluated based on the new materials. I suggest a new theory on the periodization and the characteristics of each period: a. the paleolithic period(6,000,000 B.P.-10,000 B.P.) : natural shelter, the emergence of man-made dwellings b. the neolithic period(10,000 B.P.-1,000 B.C.) : construction of pit house c. the bronze period(1,000 B.C.- 300 B.C.) : construction of semi-pit house d. the early metalic period(300 B.C. - 300 AD.) : construction of house on the ground level development of the Ondol system e. the ancient kingdomes period(300 AD - 700 AD): classification of housing type

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History of the College Scholastic Ability Test in Mathematics Section (대학수학능력시험 수학(수리) 영역 변천사)

  • Jeon, Young Ju
    • Journal for History of Mathematics
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    • v.26 no.2_3
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    • pp.177-195
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    • 2013
  • This study is the analysis of the concepts and the characteristics of the mathematics section of the College Scholastic Ability Test. The study starts with division of the history of the College Scholastic Ability Test into four periods. These are Introduction Period(school year 1994-1996), Adjustment Period(school year 1997-2004), Development Period(school year 2005-2011) and Conversion Period(up to present since school year 2012). The periodical division of the Mathematics section is considered as identical with that of the College Scholastic Ability Test. So we investigate the characteristics of the Mathematics section through the periodical classification. This study also proposes some tasks for the future Mathematics section of the College Scholastic Ability Test.

A Research on the Korean Private Residence Published in Kuchie, ′Chosun and Architecture′ during the Japanese Colonial Period (일제강점기 『조선과건축』 권두그림에 게재된 조선인 개인주택에 대한 고찰)

  • Suh Kuee-Sook
    • Journal of the Korean housing association
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    • v.15 no.4
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    • pp.75-86
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    • 2004
  • This research is about the Korean private residence as the actual housing published in Kuchie, 'Chosun and Architecture'. Research about the Korean private residence during the Japanese colonial period is important to find out the influence of foreign culture on Korean housing during that period. This research is necessary to reveal the tendency of modernization of Korean housing and how the foreign cultural relationship transformed and applied to the Korean housing. This research was carried out mainly on the 16 Korean private residences published in 'Chosun and Architecture'. The main subject of this research is to analyze the architectural floor plan, building material and heating facilities etc. Other important themes of the research are the practical side of actual housing plan, interior furnitures and fittings, electrical fittings and the classification of life style.