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First Principles Calculations on Magnetism of CrPt3(001) Thin Films (CrPt3(001) 박막의 자성: 제일원리계산)

  • Jeong, Tae Sung;Jekal, Soyoung;Rhim, S.H.;Hong, S.C.
    • Journal of the Korean Magnetics Society
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    • v.27 no.2
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    • pp.41-48
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    • 2017
  • Recent study shows that ordered alloy of $L1_2$ $XPt_3$ (M = V, Cr, Mn, Co, and Fe) exhibits various magnetic phases such as ferromagnetic-to-antiferromagnetic transition at the $MnPt_3$ surface. Moreover, it has been argued that $CrPt_3$, in particular, possess large magnetocrystalline anisotropy and Kerr rotation with possible violation of Hund's rule. As such, we extend our work to thickness dependence of the magnetic structure of $CrPt_3$ thin film using density functional theory. Magnetic ground state of the bulk $CrPt_3$ turns out to be ferromagnetic (FM), where other magnetic phases such as A-type (A-AF), C-type (C-AF), and G-type antiferromagnetic (G-AF) state have higher total energies than FM by 0.517, 0.591, and 0.183 eV, respectively, and magnetic moments of Cr in bulk are respectively 2.807 (FM), 2.805 (A-AF), 2.794 (C-AF) and $2.869_{{\mu}_B}$ (G-AF). We extend our study to $CrPt_3$(001) thin films with CrPt-and Pt-termination. The thickness and surface-termination dependences of magnetism are investigated for 3-9 monolayers (ML), where different magnetic phases from bulk emerge: C-AF for CrPt-terminated 3 ML and G-AF for Pt-terminated 5 ML have energy difference relative to FM by 8 and 54 meV, respectively. Furthermore, thickness- and surface-termination-dependent magnetocrystalline anisotropies of the $CrPt_3$(001) films are discussed.

Derivation of rock parameters from Televiewer data (텔레뷰어에 의한 토목설계 매개변수의 산출)

  • Kim Jung-Yul;Kim Yoo-Sung
    • 한국지구물리탐사학회:학술대회논문집
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    • 1999.08a
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    • pp.137-155
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    • 1999
  • Recently, Televiewer(Borehole Acoustic Scanner(Televiewer)) has come to be widely used specially for the general engineering construction design. The Televiewer tool using a focussed acoustic beam is to detect the amplitude and traveltime of each reflected acoustic signal at the wall, resulting in the amplitude- and traveltime image respectively. Fractures can be well detected, because they easily scatter the acoustic energy due to the highly narrow beam. In addition, the drilling work will rough the borehole wall so that the acoustic energy can be scattered simply due to the roughness of the wall. Thus, the amplitude level can be directed associated with the elastic properties(impedance) and the hardness of the rock as well. Meanwhile, the traveltime image provides an information about the borehole shape and can be converted to a high precision 3D caliper log(max. 288 arms). In this paper, based on the high resolution of Televiewer images, general evaluation methods are illustrated to derive very reliable rock parameters.

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e-Navigation 관련 산업현황에 관한 기초연구

  • Choe, Han-Gyu;Gang, Byeong-Jae
    • 선박안전기술공단연구보고서
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    • s.4
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    • pp.1-108
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    • 2007
  • 2007. 7. 23 IMO의 NAV(항해안전전문위원회)53차 회의에서는 e-Navigation을 해상에서의 안전, 보안, 해양환경보호를 목적으로 전자적인 수단에 의해 선박과 육상에서 해양정보를 수집, 교환, 표시함으로써 항구와 항구간의 항해 및 관련된 서비스를 향상시키는 것으로 정의하고 있다.2005년 11월 영국의 교통부 장관 Stephen 박사는 Royal Institute ofNavigation에서의 연설에서 해상안전과 환경보호를 위하여 선박의 항해를 감시하는 관제소 및 항행하는 선박에 유용하고 정확한 정보가 더 많이 필요함을 역설하였다. 그리고 첨단 기술에 의해 자동화된 항공 항법분야를 예로들면서, 선박의 항법 분야도 항해와 관련된 모든 시설 및 작업을 전자적 수단으로 대체하는 개념인 e-Navigation으로 전환되어야 하며 영국은 이에 필요한 작업을 주도하겠다는 의견을 피력하였다. Stephen은 e-Navigation 도입으로 얻을 수 있는 이익으로 첫째, 항해 실수로 인한 사고 확률저감, 둘째,사고 발생 시 인명 구조 및 피해 확산을 위한 효율적 대응, 셋째, 전통적인항해시설 설치 불필요로 인한 비용 저감, 넷째 선박입출항 수속의 간편화 및항로의 효율적 운용으로 인한 상업적 이익 등을 들었다. 반면에e-Navigation 체계로 전환 시 예상되는 장애로는 첫째, 체계 구축을 위한 비용(특히 개발도상국가들의 경우 어려움 예상), 둘째, e-Navigation의 성과 달성을 위하여 세계 전 해역의 모든 선박이 e-Navigation 체계에 동참하도록유도하는 문제, 셋째, 전자해도 표시 및 선교 장비들에 대한 표준화 문제, 넷째, 육상에 설치할 e-Navigation 센터의 설계 및 구축 등을 꼽았다.IMO는 2005년 81차 MSC(해사안전위원회) 회의에서 영국이 일본, 마샬아일랜드, 네덜란드, 노르웨이, 싱가포르, 미국과 공동으로 제안한 ‘e-Navigation전략 개발’ 의제를 2006년 82차 MSC 회의에서 채택하고, NAV(항해 전문위원회)를 통하여 2008년까지 e-Navigation의 구체적 개념을 정립하고 향후 개발하여야 할 전략적 비전과 정책을 수립하기로 하였다. 이어서 영국을 의장으로 e-Navigation 전략개발 통신작업반이 구성되었는데, 지난 년간 19개국, 16개 전문기관이 참여하여 아래의 작업이 수행되었다. ○ e-Navigation 개념의 정의와 목적 ○ e-Navigation에 대한 핵심 이슈 및 우선 순위 식별 ○ e-Navigation 개발에 따른 이점과 단점의 식별 ○ IMO 및 회원국 등의 역할 식별 ○ 이행계획을 포함한 추가 개발을 위한 작업계획의 작성 IMO에서 수행되고 있는 e-Navigation 전략 개발 의제 일정은 2008년까지이다. 이 전략 개발에 있어서 중요한 요소는 e-Navigation이 포함할 서비스범위, 포함하는 서비스 제공에 필요한 인프라 및 장비의 식별, 인프라 구축및 운용비용을 부담할 주체에 대한 논의, e-Navigation으로 인한 이익과 투자비용에 대한 비교 분석 등이다. 이 과정에서 정부, 선주, 항만운영자, 선원등의 입장 차이와 선진국과 개발도상국 간의 경제 수준 차이는 전략 개발에있어 큰 어려움을 줄 것이므로, 이들이 합의된 전략을 만들기 위해서는 예정된 기간보다 다소 늦어질 가능성도 있다.e-Navigation 전략 개발이 완료되면 1단계로는 해상교통 관제시스템, 선박선교 장비, 무선 통신장비 등에 대한 표준화 작업이 이루어질 것이다. 이 과정에서 각국 간에 자국 보유 기술을 표준화시키기 위한 경쟁이 치열할 것으로 예상된다. 2단계에서는 e-Navigation 체계 하에서의 다양하고 풍부한 서비스 제공을 위한 관련 소프트웨어 및 하드웨어의 개발이 이루어질 것으로전망되는데, 이는 지난 10년간 육상에서 인터넷망 설치 후 이루어진 관련 서비스 산업의 발전을 돌아보면 쉽게 짐작할 수 있을 것이다.e-Navigation 체계 하에서 선박의 항해는 현재와는 전혀 다른 패러다임으로 바뀔 것이다. 예를 들어 현재 입출항 시 요구되던 복잡한 절차는one-stop 쇼핑 형태로 단순화되고, 현재 선박 중심의 항해에서 육상e-Navigation 센터가 적극적으로 관여하는 항해 체계로 바뀔 것이며, 해상정보의 공유와 활용이 무선 인터넷을 통해 보다 광범위하게 이루어질 것이 다.e-Navigation의 잠재적 시장 규모는 선박에 새로이 탑재될 지능형 통합 항법시스템 구축과 육상 모니터링 및 지원 시스템 등 직접 시장이 약 50조원,전자해도, 통신장비, 관련 서비스 컨텐츠 등 간접 시장의 규모가 150조원으로 총 200조원으로 대략 추산하고 있다. 향후 이 거대한 시장을 차지하기 위한 전략 수립이 필요한 시점이다. 지금까지 항해 장비 관련 산업은 선진국의일부 업체들에 의해 독점되어 왔다. 우리나라는 조선과 해운에서 모두 선진국임에도 불구하고 이 분야에서는 대부분 수입에 의존해 왔다. e-Navigation체계 하에서는 전체 시장이 커지고 장비의 사양이 표준화됨에 따라 어느 소수 업체가 현재처럼 독점하기는 더 이상 어려울 것으로 예상된다. 따라서e-Navigation은 우리나라도 항해 장비 분야 시장을 차지할 수 있는 좋은 기회라고 할 수 있다. 특히 조선 1위의 장점을 적극 활용한다면 다른 나라보다우위의 경쟁력을 확보할 수도 있다. 또한, 서비스 분야의 시장은 IT 기술과밀접한 관계가 있으므로 IT 강국인 우리나라가 충분한 경쟁력을 갖고 있다고 할 수 있다.그러나, EU를 비롯한 선진국에서는 이미 e-Navigation 에 대비한 연구를10여년 전부터 수행해 왔다. 앞에서 언급한 EU의 MarNIS 사업은 현재 거의마무리 단계로 당장 실용화 할 수 있는 수준에 있는 것으로 보인다. 늦었지만 우리도 이를 따라잡기 위한 연구를 서둘러야 할 것이다. 국내에서도e-Navigation의 중요성을 깊이 인식하고, 2006년에는 관련 산학연 전문가들로 작업반을 구성하여 워크숍 등을 개최한 바 있다. 또한 해양수산부에서도e-Navigation 핵심기술 개발을 위한 연구사업을 기획 추진하고 있다.그러나 현재 항해통신장비들의 기술기준은 ITU의 전파규칙(RR)과 IMO결의 및 SOLAS 협약을 따르고 있는데 이들 규약이나 결의에 대한 국제적인 추이와 비교할 때 국내의 기술은 표준화되지 못한 부분이 많은 실정이다.본 연구에서는 e-Navigation sytem중 표준화가 필요한 요소와 전자해도,AIS 등 e-Navigation(통합전자항법시스템)관련 국내산업현황 실태조사를 통해 국내 e-Navigation기술개발 동향에 대해 조사하고자 한다.

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Clinical Study on Laryngo - Microscopic Surgery For Vocal Nodules and Polyps (후두결절 및 폴립의 후두미세 수술에 관한 임상연구)

  • 문영일
    • Proceedings of the KOR-BRONCHOESO Conference
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    • 1983.05a
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    • pp.11.2-11
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    • 1983
  • Vocal nodules and polyps are much more frequent in singers, public speakers, teachers and actors. Voice trauma and voice misuse, at times associated with mild inflammatory reaction, appear to be important in their etiology. It is generally agreed that vocal cord nodules and polyps are inflammatory in nature and they arise in the subepithelial layer of loose connective tissue of the vocal cord. Since the junction of anterior and middle thirds of the membranous cord and has the greatest amplitude of vibration. This is the site of predilection for vocal cord nodules. The author performed laryngomicrosurgery for 70 cases of vocal nodules and polyps at Ewha Womans University Hospital during the period of 5 years. The result obtained were as follows ; 1) Surgical excision is not necessarily the best approach because vocal nodules in the early stages will resolve with the simplest voice therapy. 2) In children, surgery is rarely indicated because most nodules in children regress during adolescence. 3) For patients who use their voices professionally, voice therapy is indicated for three months. 4) If after three month of conservative treatment the cord lesion does not improve and the patient it still dissatisfied with his voice, laryngomicrosurgery can then be considered. 5) The small cuffed endotracheal tube in the interarytenoid space helps to keep the cords immobile and in an abducted position. 6) Removal of the nodule shoule be started by gentle retraction posteriorly and as soon as a tear appears anterior to the nodule. 7) On occasion it is preferable to start the dissection with a siccle knife while the nodule is held on the stretch. 8) Voice rest should be maintained for a week following which the free edges of the cords are usually healed.

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Total Polyphenol Contents and Antioxidant Activities of Methanol Extracts from Vegetables produced in Ullung Island (울릉도산 산채류 추출물의 총 폴리페놀 함량 및 항산화 활성)

  • Lee, Syng-Ook;Lee, Hyo-Jung;Yu, Mi-Hee;Im, Hyo-Gwon;Lee, In-Seon
    • Korean Journal of Food Science and Technology
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    • v.37 no.2
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    • pp.233-240
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    • 2005
  • To discover new functional materials using edible plants, antioxidant activities of methanol extracts from various parts of seven wild vegetables were investigated in vitro. Total polyphenol contents, determined by Folin-Denis method, varied from 16.74 to $130.22{\mu}g/mg$. Radical-scavenging activities of methanol extracts were examined using ${\alpha},\;{\alpha}-diphenyl-{\beta}-pirrylhydrazyl$ (DPPH) radicals and 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) assay. Inhibition effects on peroxidation of linoleic acid determined by ferric thiocyanate (FTC) method and on oxidative degradation of 2-deoxy-D-ribose in Fenton-type reaction system were dose-dependent. Athyrium acutipinulum Kodama (leaf and rood), Achyranthes japonica (Miq.) Nakai (seed), and Solidago virga-aurea var. gigantea Nakai (root) showed relatively high antioxidant activities in various systems.

A Survey on Housewives' Consumption Pattern and Nutrition Knowledge about Vegetables (주부의 채소 소비형태 및 영양지식에 대한 연구)

  • Kang, Keum-Jee;Chung, Mi-Sook
    • Journal of the Korean Society of Food Culture
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    • v.10 no.5
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    • pp.377-390
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    • 1995
  • This study was to investigate the consumption pattern and nutrition knowledge about vegetables of 184 housewives attending the school of adult and continuing education attached to DukSung Women's University. The results were summarized as follows; the average vegetable expenses were $10,000{\sim}20,000$ won per week. The frequency of purchasing vegetables was $2{\sim}3$ times a week. Respondents usually bought the vegetables at local markets and supermarkets. As for buying vegetables, all of respondents kept in mind all the time the organic vegetables were better. The price was the most important factor of their purchase in the low income households. In the family, the vegetable dishes were favored by housewives most and by sons least. Among the vegetable cooking methods, Kimchi was the most frequently used and salad was the least. Forty four percent of the respondents experienced purchasing ready made vegetable dishes in the market. The reason they bought ready made ones was the special taste of the dishes. The rest of respondents never bought cooked vegetable dishes because they thought the dishes unsanitary. Twenty seven percent of the respondents experienced purchasing. The reason for not purchasing Kimchi was the housewives' traditional prejudice of buying Kimchi in the market. Respondents have a considerable knowledge that 42 kinds of vegetables could be good for certain disease and 10 kinds of vegetables might be harmful for certain disease.

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An Analysis of Papers used in Historical Manuscrips (조선시대 고문서(古文書)에 사용된 종이 분석)

  • Son, Ke-Young
    • Journal of Korean Society of Archives and Records Management
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    • v.5 no.1
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    • pp.79-105
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    • 2005
  • This study is that the name from Tagjijunjeol is compared with the actual papers used in historical documents. I have selected the families having had influencing power in Gyungi-Do(京畿道), Gyungsang-Do(慶尙道), Jeonra-Do(全羅道), Chungcheung-Do(忠淸道), and analyzed 1504 articles of historical documents owned by those families. I checked up each papers used in historical documents in it's shape of screens, density, raw material. I cannot find the feature of it's region, but prominent feature according to the types and period of historical documents. At first, I have surveyed the impressions of screen marks in papers. The number of strips can be divided into two cases, around 10 and around 17. The case around 17 is similar to the number seen in the book paper of the early Joseon Dynasty, but the case around 10 is rare. Dard Hunter said in his book, published in 1933, that screens were made of Korean grass(Miscanthus sp.) at that time in Korea. I guess the impressions of screen marks of the case around 10 was made of Korean grass, Miscanthus sp.. The case around 10 and the case around 17 were not different in period, but the contemporary appearance. However, if we look into the change of strips' number, we can learn that it becomes more dense as time goes by. The intervals of hair stitch, contrary to book paper, have appeared irregularly and a short hair stitch was frequently found between long hair stitches. This was the result of fastening extra stitch to increase the firmness of strips, as the part of screens which was frequently touched by hands would wear out easily. Then, have look into the density. Each kinds of historical documents had a wide range of density. But the average have had relationship with the kinds of paper written in Tagjijunjeol. The historical documents having the same item of paper have kept similar densities. From the density variation of Gosingyoji(告身敎旨), the letter of appointment the official rank over 5 by king, based on time periods, we can see a great disparity between before and after Imjin-waeran war. Before Imjin-waeran war paper's quality was high, right after Imjin-waeran war went abruptly down, and went gradually up just from 1650's, but since 1700's quality has not risen more, kept the value. On the contrary, the density of Gyocheop(敎牒), the letter of appointment the official rank under 5 by the Ministry of Personnel and the Ministry of Military, have not had a great disparity according to time periods, but had a lower density than Gosingyoji. Joseon Dynasty has strictly divided Gosingyoji appointing the official rank over 5 from Gyocheop appointing the official rank under 5, it seems to distinguish the appointment by king from the appointment by Ijo(吏曹), the Ministry of Personnel and Byeongjo(兵曹), the Ministry of Military.

A novel cold-active lipase from Psychrobacter sp. ArcL13: gene identification, expression in E. coli, refolding, and characterization (새로운 Psychrobacter sp. ArcL13 유래 저온활성 지질분해효소 : 유전자 분리동정, 대장균에서의 발현, refolding 및 특성 연구)

  • Koo, Bon-Hun;Moon, Byung-Hern;Shin, Jong-Suh;Yim, Joung-Han
    • Korean Journal of Microbiology
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    • v.52 no.2
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    • pp.192-201
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    • 2016
  • Recently, Psychrobacter sp. ArcL13 strain showing the extracellular lipase activity was isolated from the Chuckchi Sea of the Arctic Ocean. However, due to the low expression levels of the enzyme in the natural strain, the production of recombinant lipase is crucial for various applications. Identification of the gene for the enzyme is prerequisite for the production of the recombinant protein. Therefore, in the present study, a novel lipase gene (ArcL13-Lip) was isolated from Psychrobacter sp. ArcL13 strain by gene prospecting using PCR, and its complete nucleotide sequence was determined. Sequence analysis showed that ArcL13-Lip has high amino acid sequence similarity to lipases from bacteria of some Psychrobacter genus (84-90%) despite low nucleotide sequence similarity. The lipase gene was cloned into the bacterial expression plasmid and expressed in E. coli. SDS-PAGE analysis of the cells showed that ArcL13-Lip was expressed as inclusion bodies with a molecular mass of about 35 kDa. Refolding was achieved by diluting the unfolded protein into refolding buffers containing various additives, and the highest refolding efficiency was seen in the glucose-containing buffer. Refolded ArcL13-Lip showed high hydrolytic activity toward p-nitrophenyl caprylate and p-nitrophenyl decanoate among different p-nitrophenyl esters. Recombinant ArcL13-Lip displayed maximal activity at $40^{\circ}C$ and pH 8.0 with p-nitrophenyl caprylate as a substrate. Activity assays performed at various temperatures showed that ArcL13-Lip is a cold-active lipase with about 40% and 73% of enzymatic activity at $10^{\circ}C$ and $20^{\circ}C$, respectively, compared to its maximal activity at $40^{\circ}C$.

Flexible Specialization: A New Paradigm for Modern Industrial Society ? (柔軟的 專門化(Flexible Specialization) : 현대 産業社會의 새로운 패러다임 ?)

  • Lee, Deog-An
    • Journal of the Korean Geographical Society
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    • v.28 no.2
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    • pp.148-162
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    • 1993
  • There is much speculation that modern capi-talist society is undergoing fundamental and qualitative chnge towards flexible specialization. The purpose of this study is to examine this hypothesis. This paper focusses on: the idea of flexible specialization; the significance of this transition; industrial district; and the implicati-ons of this new production system for Korean industrial space. Main arguments of this study are as follows: First, as all different groups of researchers apply the idea of flexible specialization according to their own specifications, the current debate on this topic is not much fruitful. Not surpri-singly, the concept of flexible specialization has overlapped with subocontracting. This intergration of subcontracting into flexible specialization systems, however, is inappropriate because the two concepts have different historical contexts. The other cause of this controversy is its inherent weekness, conceptual ambiguity. Thus, today's flexibility becomes tomorrow's rigidity. Secondly, transition towards flexible speciali-zation has only been partially achieved even in advanced capitalist countries. The application of dualistic explanatory framework, such as rigidity versus flexibiity, mass production versus small-lot multi-product production, and de-skilling versus re-skilling, has resulted in great exaggeration of the transformation, from Fordism to post-Fordism. There is no intermediary part between two places. Considering that the workers allocated to the Fordist mass production assembly line are not as large as one might imagine, the shift from mass to flexible production has only limited implications for the transformation of capitalist economy. Thirdly, 'industrial district' contorversy has contributed to highlighting the importance of small firms and areas as production space. The agglomeration of small firms in specific areas is common in Korea, but it is quite different from the industrial district based on flexible specialization. The Korean phenomenon stems from close interactions with its major parent firm rather than interactions between flexible, specialized, autonomous and technology-intensive smll firms. Most Korean subcontractors are still low-skilled, labour-intensive, and heavily dependent on their mojor parent firms. Thus, the assertion that the Seoul Metropolitan Area adopts flexible specialization has no base. Fourthly, the main concern of flexible speciali zation is small firms. However, the corporate organization that needs product diversification and technological specialization is oligopolistic large corporations typified by multinational corporations. It is because of this that most of these organizations are adoptiong Fordist mass production methods. The problem of product diversification will be resolved naturally if economic internationalization progresses further. What is more important for business success is the quality and price competitiveness of firms rather than product diversification. Lastly, in order to dispel further misunderst-anding on this issue, it is imparative that the conceptual ambiguity is resolved most urgently. This study recommends adoption of more speci-fied and direct terminology (such as, factory automation, computer design, out-sourcing, the exploitation of part-time labor, job redesign) rather than that of ideological ones (such as, Taylorism, Fordism, neo-Taylorism, neo-Fordism, post-fordism, flexible specialization, peripheral post-Fordism). As the debates on this topic just started, we still have long way to go until consensus is reached.

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Teacher's Practice of Activity Materials in the Housing Area of Middle School Technology & Home Economics Textbook (중학교 교사의 기술.가정 주생활영역 활동자료 활용실태)

  • Lee, Young-Doo;Cho, Jea-Soon
    • Journal of Korean Home Economics Education Association
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    • v.20 no.4
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    • pp.157-171
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    • 2008
  • The year of 2007 Reformed Curriculum encourages various activity materials in the textbook facilitate students oriented self-help learning. The purpose of this paper is to find out how much the activity materials in housing area of middle school Technology and Home Economics are practiced in the class and why they are used or not used. The data were collected from 253 middle school teachers who had ever taught the housing unit in any of 6 textbooks. The analyses indicated that the most frequent teaching methode was lecture based on the textbook and internet data focused on the figures and contents of the individual textbook. The average rate of practicing the activity materials was differ by textbooks and the characteristics of the materials such as type of materials, feature of non sentence materials, and type of activity. The main two reasons to practice the activity materials were it's adequacy to class goals and application to everyday life. Low interests of students and shortage of time were the two main reasons why not used the materials. Textbook writers should consider these reasons as well as the characteristics of activity materials practiced in the class by the teachers in order to meet the goals of the reformed as well as current curricula.

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