• 제목/요약/키워드: micro-history

검색결과 123건 처리시간 0.027초

도시역 거수목의 잔존형태와 그 효용성에 관한 연구 (A Study on the Remnant Forms and Effects of Big Trees in an Urban Area)

  • 김용수;임원현
    • 한국조경학회지
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    • 제24권3호
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    • pp.14-28
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    • 1996
  • Purposes of this study were to provide the basic information for the management policy for more preserve and refreshing Gusumok-big and old tree. Fundamental directions for the protection and application of Gusumok were suggested by comparing and analyzing present conditions and remnant forms of Gusumok as preserved tree in Kyung-ju and its function and the role of Gusumok according to the civilization and diference between past and present. The main results of the study are as follows ; There are 121 Gusumok which designated as a preserved tree in Kyung-ju. It is distributed all over the Kyung-ju city uniformly and located in the enterance or the center of a village having high interests of most of residents. in the course of a civilzation, the percintage of a loss of an urban Gusumok is higher than that of a rural Gusumok and its function is also changed so much. A modern function of Gusumok can be divided into a positive and negative one. A positive function is the offer of amenity and the place of receation, formation of culture and ragulation of micro climate. A negative function is of psycholosical and functional reversed function. having a close relation with our life, Gusumok offers an amenity place to our life to make us feel soft and comfortable as well as developes the quality of our life. Gusumok has an important meaning in mordern society in that it contibutes to our village being better to live by having a historical meaning and creating a symbolic culture and history.

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벼 잎 표면에서 액적의 이방성 흐름 특성에 관한 연구 (A Study on the Anisotropic Flow Characteristics of Droplets on Rice Leaf Surface)

  • 김태완
    • Tribology and Lubricants
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    • 제33권6호
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    • pp.251-255
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    • 2017
  • In this study, we aimed to clarify the wettability and anisotropic flow characteristics of rice leaves as a basic study for engineering applications of anisotropic flow characteristics of rice leaf surface. To investigate the surface structure of rice leaf, the micro grooves and asperities of rice leaves were analyzed and quantified by scanning electron microscope, Confocal laser scanning microscopy, and stylus profilometer. The analysis of the structure of rice leaf surface confirmed that asymmetrical cone - like protrusions in leaf veins were inclined toward the leaf tip. The static contact angle test showed that the contact angle at the midline vein or leaf vein location where the micropapilla is concentrated is about $20^{\circ}$ higher than the leaf blade position. The contact angles of fresh and dried rice leave were also compared. The dried rice leaves showed a contact angle of about $5^{\circ}$ to $15^{\circ}$ higher than that of fresh leaves, suggesting that the volume of the protrusions decreased as the water was removed, thus reducing the contact area with the droplet. In the contact angle history test the hysteresis in the leaf tip direction was found to be much lower than that in the leaf petiole direction. This results can be explained that asymmetrical cone - like protrusions had a significant effect on the droplet flow characteristics through contact angle hysteresis experiment.

이차이온질량분석기의 원리와 분석법 동향 (Secondary Ion Mass Spectrometry : Theory and Recent trends)

  • 변미랑;김다영;홍태은
    • 세라미스트
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    • 제22권4호
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    • pp.357-367
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    • 2019
  • Secondary Ion Mass Spectrometry(SIMS) is an analytical method that measures the distribution and concentration of elements or compounds by analyzing the mass of secondary ions released by irradiating ion beams with energy of hundreds eV to 20 keV on the sample surface. Unlike other similar analytical instruments, SIMS directly detect the elemental ions that constitute a sample, allowing you to accurately identify components and obtain concentration information in the depth direction. It is also a great feature for measuring isotopes and analyzing light elements, especially hydrogen. In particular, with the development of materials science, there is an increasing demand for trace concentration analysis and isotope measurements in the micro-regions of various materials. SIMS has a short history compared to other similar methods; nevertheless, SIMS is still advancing in hardware and is expected to contribute to the development of materials science through research and development of advanced analytical techniques.

A TOF-SIMS Study of Artificially Photoaged Silk Fabrics

  • Lee, Boyoung;Ryu, Hyoseon;Park, Sohyun
    • 보존과학회지
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    • 제34권2호
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    • pp.129-135
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    • 2018
  • Scientific investigation of cultural heritage can provide important information to understand the context of the object. To know the characteristics of the material is also an essential part of objects management and conservation. However, the identification and characterization of organic dyes used in archaeological and historical textiles are often limited by the restrictions in sampling. To cope with the difficulties, applications of high-performance techniques of surface analysis, such as Time of Flight-Secondary Ion Mass Spectra (TOF-SIMS) could be considered as a non or micro-destructive option. This study aims to examine the applicability of TOF-SIMS analysis to the detection of organic dyes from historical textiles. A group of silk fabrics dyed with vegetable dyes were artificially photo-aged to different degrees and analyzed with TOF-SIMS. Molecular and fragment ions from indigo were successfully detected from the aged samples; however, only some fragment ions were observed from gardenia and safflower dyed fabrics. Further studies with actual historical samples with extended examination scope would be necessary to assess the validity of this technique.

Thermal cracking analysis of concrete with cement hydration model and equivalent age method

  • Tian, Ye;Jin, Xianyu;Jin, Nanguo
    • Computers and Concrete
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    • 제11권4호
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    • pp.271-289
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    • 2013
  • In this research, a developed microstructural model of cement particles was presented to describe the cement hydration procedure. To simplify the hydration process, the whole hydration was analyzed in a series of sub-steps. In each step, the hydration degree, as well as the microstructural size of the hydration cell, was calculated as a function of the radius of the unreacted cement particles. With the consideration of the water consumption and the reduction of the interfacial area between water and hydration products, the micro-level expressions of the cement hydration kinetics were established. Then the heat released and temperature history of the concrete was carried out with the hydration degree obtained from each sub-steps. The equivalent age method based on the Arrhenius law was introduced in this research. Based on the equivalent age method, a maturity model was applied to describe the evolution of the mechanical properties of the material during the hydration process. The finite element program ANSYS was used to analyze the temperature field in concrete structures. Then thermal stress field was calculated using the elasticity modulus obtained from code formulate. And the risk of thermal cracking was estimated by the comparison of thermal stress and concrete tensile strength.

후두미세수술의 역사와 기구의 발전 (History and Instrumental Development of Laryngeal Micro-Surgery)

  • 우주현;김동영
    • 대한후두음성언어의학회지
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    • 제21권2호
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    • pp.97-100
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    • 2010
  • After introduction of operating microscopes and laser devices in the 1960's, monumental innovation for had been achieved in laryngeal microscopic surgery. The development of high-tech operating devices made the laryngeal surgery less invasive and more precise. There were long histories until developing of the modem instruments and surgical techniques. The simple oral mirror introduced by Bozzoni in 1807 is the beginning of laryngoscope. In 1859 Green carried out the laryngeal operation under direct view of larynx. The appearance of local topical anesthesia on throat had contributed to laryngeal surgery coming into wide use. Killian and Jackson made much contribution to developing the design of laryngoscope. After that, modem laryngeal surgery have been developed with development of the stabilizing holder of laryngoscope and optical devices. We propose carefully the direction of the development of the laryngeal surgery by historical consideration of laryngeal surgery and instrumental development.

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외국의 지방기록관과 한국의 지방기록자료관 설립 방향 (How to Establish Local Archives in Korea)

  • 박찬승
    • 기록학연구
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    • 제1호
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    • pp.107-135
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    • 2000
  • Based on the "Archives and Records Management of Public Agencies Act" enacted from the year 2000, the Korean local districts, in a near future, will establish local archives. According to this law, the archives of provincial states and municipal cities are to be conserved permanently, whereas the archives of local districts are to be conserved temporally. Subsequently, the important archives that are categorized as the permanent documents will be transferred to the provincial archives. However the Korean local districts, which are well known for long history of self-administration, are better to preserve permanent documents in their own archives. Moreover, it is necessary for the local archives to collect and compile public and private documents as well. Also it is advisable for the local archives to associate with local citizens by holding lectures and exhibitions which would endow the archives a status as the cultural centre for local districts. By doing so, the local archives could be more important to the population for their cultural and practical necessities than the remotely municipal archives. Furthermore, according to the rule of field preservation, it is better to conserve documents in the local archives. If the government will decide to transfer permanent documents to the municipal archives, the local archives are recommended to keep micro-film copy by themselves.

Influence of mineral by-products on compressive strength and microstructure of concrete at high temperature

  • Sahani, Ashok Kr.;Samanta, Amiya K.;Roy, Dilip K. Singha
    • Advances in concrete construction
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    • 제7권4호
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    • pp.263-275
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    • 2019
  • In the present work, Granulated Blast Furnace Slag (GBFS) and Fly ash (FA) were used as partial replacement of Natural Sand (NS) and Ordinary Portland Cement (OPC) by weight. One control mix, one with GBFS, three with FA and three with GBFS-FA combined mixes were prepared. Replacements were 50% GBFS with NS and 20%, 30% and 40% FA with OPC. Preliminary investigation on development of compressive strength was carried out at 7, 28 and 90 days to ensure sustainability of waste materials in concrete matrix at room temperature. After 90days, thermo-mechanical study was performed on the specimen for a temperature regime of $200^{\circ}-1000^{\circ}C$ followed by furnace cooling. Weight loss, visual inspection along with colour change, residual compressive strength and microstructure analysis were performed to investigate the effect of replacement of GBFS and FA. Although adding waste mineral by-products enhanced the weight loss, their pozzolanicity and formation history at high temperature played a significant role in retaining higher residual compressive strength even up to $800^{\circ}C$. On detail microstructural study, it has been found that addition of FA and GBFS in concrete mix improved the density of concrete by development of extra calcium silicate gel before fire and restricts the development of micro-cracks at high temperature as well. In general, the authors are in favour of combined replacement mix in view of high volume mineral by-products utilization as fire protection.

Determinants of the Extent of Individual Credit Rationing: A Case Study of Can Tho Military Commercial Joint Stock Bank, Vietnam

  • DANG, Quang Vang;TRAN, Viet Thanh Truc;VUONG, Quoc Duy
    • The Journal of Asian Finance, Economics and Business
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    • 제9권7호
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    • pp.81-91
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    • 2022
  • The aim of this paper was to analyze the determinants of the extent of individual credit rationing at Can Tho Military Commercial Joint Stock Bank (MB). The data was collected from 150 customers according to the systematic random sampling method listed in the bank. This study employed quantitative analysis methods, and Tobit regression model, to test the proposed hypotheses. The results showed that the average loan amount of an individual customer was 1,181.3 million VND, the average credit limit was 48.6%, and the average interest rate was 10.9% per year. Most of the individual customers borrowed money to buy properties. In addition, the analysis results also indicated that individual borrowers still faced some difficulties in accessing bank credit, such as cumbersome procedures, long waiting times, insufficient collateral assets, and loan documents. The results of the Tobit model pointed out that there were five factors affecting the degree of credit rationing to individual customers at the bank, including (1) Collateral, (2) Income, (3) Credit history, (4) Loan purpose, (5) Relationship between borrower and bank. Based on the empirical findings, the possible solutions for the bank and individual borrowers to improve credit efficiency for individual customers at commercial banks are obtained.

이주 유형이 자가소유에 미치는 영향에 관한 연구 : 결정요인과 이동유형 별 주거선택과의 연계성을 중심으로 (A Study on the Effects of Migration History on Tenure Choice : Focusing on the Determinants and Relationship between Migration Typology and Housing Choice)

  • 천진홍;이성우
    • 한국지역지리학회지
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    • 제13권6호
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    • pp.651-673
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    • 2007
  • 본 연구에서는 이동 유형을 지역 내 이동과 지역 간 이동으로 구분하여 각각의 원인을 고찰하는 한편 두 가지 유형의 상호 연계성을 이동 후 관찰되는 자가소유에 기초하여 분석하였다. 본 연구에서는 통계청에서 제공하는 1980년부터 2000년까지의 인구주택총조사(Census)를 활용해 우리나라 인구이동의 일반적 특성을 고찰하고 기존의 이동거리에 관한 가설을 검증하는 한편, 이동형태에 따른 자가소유의 결정요인을 분석하였다. 분석 결과 지역 간 이동과 지역 내 이동의 연계를 밝혀주는 Goodman의 세 가지 가설과 Roseman의 조정이동 가설은 우리나라에서 대부분 성립하지만 이러한 경향은 감소하는 추세인 것으로 나타났다. 이동거리에 따른 이주경력 결정요인을 살펴보면 연령이 낮을수록, 차가 거주자일수록, 교육수준이 높을수록, 가구원수가 적을수록 이동성향이 증가했다. 시간이 경과함에 따라 여성의 반복이동 성향이 증가하며 유배우자의 이동성향은 감소하였다. 단거리 이동의 경우여성의 이동성향이 남성에 비해 우세했다. 지역적 특성을 고려하기 위해 통제된 변인 중 보다 앞선 시기에 실업률이 부(-)인 지역으로 향하던 이주가 조사시점과 가까운 시기에는 정(+)인 지역으로 변화한 점과, 교원수 변인이 동일시기 정(+)인 지역에서 부(-)인 지역으로 변화한 점은 주목할 만하다. 이주 후 자가를 소유할 확률은 지역 간 이동에서 여성이 더 높았으며 연령이 증가할수록 확률이 증가하는 것으로 나타났다. 직업유형별로 살펴보면 판매직과 기능적의 경우 이동 후 자가를 소유할 확률이 가장 낮았으며 전문직 종사자는 가장 높은 확률을 보였다. 제주지역으로 이주한 가구가 타지역 이주가구에 비해 자가소유확률이 낮았으며 지가가 높은 지역을 목적지로 택한 가구일수록 자가소유 경향은 낮아졌다. 이동성향이 높은 가구는 자가소유 가능성이 낮은 것으로 나타났다.

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