• Title/Summary/Keyword: Expansion form

Search Result 699, Processing Time 0.027 seconds

Fabrication and Electrical Insulation Property of Thick Film Glass Ceramic Layers on Aluminum Plate for Insulated Metal Substrate (알루미늄 판상에 글라스 세라믹 후막이 코팅된 절연금속기판의 제조 및 절연특성)

  • Lee, Seong Hwan;Kim, Hyo Tae
    • Journal of the Microelectronics and Packaging Society
    • /
    • v.24 no.4
    • /
    • pp.39-46
    • /
    • 2017
  • This paper presents the fabrication of ceramic insulation layer on metallic heat spreading substrate, i.e. an insulated metal substrate, for planar type heater. Aluminum alloy substrate is preferred as a heat spreading panel due to its high thermal conductivity, machinability and the light weight for the planar type heater which is used at the thermal treatment process of semiconductor device and display component manufacturing. An insulating layer made of ceramic dielectric film that is stable at high temperature has to be coated on the metallic substrate to form a heating element circuit. Two technical issues are raised at the forming of ceramic insulation layer on the metallic substrate; one is delamination and crack between metal and ceramic interface due to their large differences in thermal expansion coefficient, and the other is electrical breakdown due to intrinsic weakness in dielectric or structural defects. In this work, to overcome those problem, selected metal oxide buffer layers were introduced between metal and ceramic layer for mechanical matching, enhancing the adhesion strength, and multi-coating method was applied to improve the film quality and the dielectric breakdown property.

A Case Study on Japanese Corporations' Business Transaction and Conflicts with China (일본기업의 대중거래와 분쟁에 대한 사례 연구)

  • Chung, Su-Won
    • Journal of Arbitration Studies
    • /
    • v.16 no.1
    • /
    • pp.253-275
    • /
    • 2006
  • Ever since the open and reform policy in 1987, China has adopted the socialistic market economy system and has been moving forward in economic reform. This gradually expanded their market economy. The open and reform policy achieved the highest average annual GDP growth rate of 9% and helped the country maintain high growth. China's economic growth in recent years has a lot to do with the international trading and direct investment by foreign corporations. China's entry into the WTO dramatically increased their amount of capital and investments due to their aggressive investments with foreign corporations. It is quite amazing that investments in China has been constantly increasing while the direct investments worldwide is decreasing. Moreover, increase in such investments is contributing to China's job creation, as well as, the expansion of international trading. When international economic exchange started between Japan and China in the 1970s, it was in the form of aid for developing countries, hence the collection of the investment was out of the question. It was in the 1990s that Japan started the full-scale investments with China and it was mostly centered in transfer of the production base. Japanese corporations aim was to mass produce goods less expensively using abundant and cheap labor and to sell them to Japan and other countries. The amount of Japan's exports and imports compared with China is increasing every year but the trade deficit has gone into the red. The dollar amount has been decreased from $ 27 billion in 2001 to $ 18 billion in 2003. The problems and damages in the system of justice and administrative confrontation that Japanese corporations are facing are continuously at a stand-still even after China's entry into the WTO. It has been 20 years since Japan's advance in China and during that period, the Japanese corporations brought many changes ranging from exports/imports to direct investment. Although Japan's new corporations tend to be located in the mid-western part of China, rather than the coastal areas, the region itself is not the cause for the confrontation. The problem stems from the Japanese treating the Chinese as if they were Japanese because they look similar due to their Asian ancestry. In reality the Chinese have completely different ways of doing business. Here we will take a look at the international trading and direct investment of Japanese corporations in China and study the conflicts that occurred in business transactions with China through real examples.

  • PDF

The Spatial and Temporal Analysis of Landscape Structure in Daegu Metropolitan Sphere (대구광역도시권의 시·공간적 경관구조 변화패턴 분석)

  • Choi, Won-Young;Jung, Sung-Gwan;Park, Kyung-Hun;Oh, Jeong-Hak;You, Ju-Han;Kim, Kyung-Tae
    • Journal of the Korean Association of Geographic Information Studies
    • /
    • v.8 no.2
    • /
    • pp.175-185
    • /
    • 2005
  • Governmental authorities have been trying to develop our city in respect to the growth of economy and it is true that their developmental policies have negative effects on ecosystem without doubt. To estimate these negative effects, this study is mainly focused on analysing the usage of the land according to the urban growth, and the temporal and spatial patterns between the elements which consist of the landscape of Daegu Metropolitan Sphere, by using the GIS method and the landscape indices. The results of the this study are as follow; the urban areas widened for $193.4km^2$ due to the shift of the urban function, and the forest areas were encroached for $455.6km^2$ into other landcover patterns. It was the shift of the agriculture areas that are given the most influence in those procedures since those developmental conditions are relatively satisfactory. Moreover the forest areas are structurally fragmented into the complicated form, and also the patterns of adjacent patches are become complex. These transitions are regarded as causes of increased external interventions to the forest areas, and these could possibly deteriorate the soundness of forest areas by reducing the core areas which are habitats of species. In conclusion, the results of this study evaluate the influence of much broader urban development on environment structure around urban and mutual relationship between them. In addition, it can provide methods and basic informations for the establishment of metropolitan urban plan after due considerations of the landscape ecological principle.

  • PDF

Numerical investigation into flow noise source of a convergent-divergent nozzle in high pressure pipe system using wavenumber-frequency analysis (파수-주파수 분석을 통한 고압 배관 내 수축 확장 노즐의 유동 소음원에 대한 수치적 연구)

  • Ku, Garam;Lee, Songjune;Kim, Kuksu;Cheong, Cheolung
    • The Journal of the Acoustical Society of Korea
    • /
    • v.36 no.5
    • /
    • pp.314-320
    • /
    • 2017
  • A pressure relief valve is generally used to prevent piping systems from being broken due to high pressure gas flows. However, the sudden pressure drop caused by the pressure relief valve produces high acoustic energy which propagates in the form of compressible acoustic waves in the pipe and sometimes causes severe vibration of the pipe structure, thereby resulting in its failure. In this study, internal aerodynamic noise due to valve flow is estimated for a simple contraction-expansion pipe by combining the LES (Large-Eddy Simulation) technique with the wavenumber-frequency analysis, which allows the decomposition of fluctuating pressure into incompressible hydrodynamic pressure and compressible acoustic pressure. In order to increase the convergence, the steady Reynolds-Averaged Navier-Stokes equations are numerically solved. And then, for the unsteady flow analysis with high accuracy, the unsteady LES is performed with the steady result as the initial value. The wavenumber-frequency analysis is finally performed using the unsteady flow simulation results. The wavenumber-frequency analysis is shown to separate the compressible pressure fluctuation in the flow field from the incompressible one. This result can provide the accurate information for the source causing so-called acoustic-induced-vibration of a piping system.

The surface kinetic properties of $ZrO_2$ Thin Films in dry etching by Inductively Coupled Plasma

  • Yang-Xue, Yang-Xue;Kim, Hwan-Jun;Kim, Dong-Pyo;Um, Doo-Seung;Woo, Jong-Chang;Kim, Chang-Il
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2009.06a
    • /
    • pp.105-105
    • /
    • 2009
  • $ZrO_2$ is one of the most attractive high dielectric constant (high-k) materials. As integrated circuit device dimensions continue to be scaled down, high-k materials have been studied more to resolve the problems for replacing the EY31conventional $SiO_2$. $ZrO_2$ has many favorable properties as a high dielectric constant (k= 20~25), wide band gap (5~7 eV) as well as a close thermal expansion coefficient with Si that results in good thermal stability of the $ZrO_2/Si$ structure. In order to get fine-line patterns, plasma etching has been studied more in the fabrication of ultra large-scale integrated circuits. The relation between the etch characteristics of high-k dielectric materials and plasma properties is required to be studied more to match standard processing procedure with low damaged removal process. Due to the easy control of ion energy and flux, low ownership and simple structure of the inductively coupled plasma (ICP), we chose it for high-density plasma in our study. And the $BCl_3$ included in the gas due to the effective extraction of oxygen in the form of $BCl_xO_y$ compound In this study, the surface kinetic properties of $ZrO_2$ thin film was investigated in function of Ch addition to $BCl_3/Ar$ gas mixture ratio, RF power and DC-bias power based on substrate temperature. The figure 1 showed the etch rate of $ZrO_2$ thin film as function of gas mixing ratio of $Cl_2/BCl_3/Ar$ dependent on temperature. The chemical state of film was investigated using x-ray photoelectron spectroscopy (XPS). The characteristics of the plasma were estimated using optical emission spectroscopy (OES). Auger electron spectroscopy (AES) was used for elemental analysis of etched surface.

  • PDF

Gravitropism in the Salt-Stressed Primary Root of Maize (Zea mays) (염분 스트레스에 노출된 옥수수(Zea mays) 뿌리의 굴중성 반응)

  • Han, Du-Yeol;Lee, Young-Na;Kim, Yeo-Jae;Park, Woong-June
    • Journal of Life Science
    • /
    • v.18 no.8
    • /
    • pp.1164-1168
    • /
    • 2008
  • We investigated gravitropic responses in the primary root of maize (Zea mays) seedlings which were exposed to salt stress. The maize roots salt-stressed with higher than 100 mM NaCl or KCl started to reveal enhanced gravitropic curvature after 2 hours form the gravi-stimulation. Such a promotion was not caused by sodium phosphate, but invoked by potassium phosphate, indicating the active component is $K^{+}$. Because NaCl increased gravitropic curvature, despite that $Na^{+}$ did not played any role, we evaluated the role for $Cl^{-}$ by comparing the effects of $MgCl_2$ and $MgSO_4$. The enhancement of the curvature only with $MgCl_2$ revealed that $Cl^{-}$ played a role in the gravi-response, indicating the involvement of anion channels. These results suggest that both of $K^{+}$ and $Cl^{-}$ play roles in the regulation of osmosis that is required for cell expansion in gravitropism as well as in nyctinasty and stomatal opening.

A Study on the application of the Froebel Systems in the F. L. Wright's Architecture (프랭크 로이드 라이트 건축에 나타난 프뢰벨 시스템의 적용에 관한 연구)

  • Kim, Min-Joung;Oh, Zhang-Huan;Lee, Kang-Up;Ryu, Jae-Ho
    • Korean Institute of Interior Design Journal
    • /
    • v.19 no.6
    • /
    • pp.47-58
    • /
    • 2010
  • Frank Lloyd Wright(1867-1959) was regarded as the pioneer of the modern architecture in the beginning and transition period of 20th century. His works have the pure shape form which have the deep relationship with the organic architecture. Wright told himself that the Froebel System had an influence on his works a lot. This study have researched about the three dimensional application of the Froebel System in his works with assembling and disassembling. Also the two dimensional application in the diagonal and circular plans are the one of the subjects here. The following conclusions are reached. First, The similar of the Wright's works and the Froebel System was the application of the similar principles rather than the copy of the method, which are the accent of the center, the composition of the part and whole, the understanding of the composition principle through the unit system and the unfolding of the crystal by rotation. Even thought the Wright's works have the triangle, square, hexagonal shape, the way of the expansion from the centered space was same. Also the space formed by the division of the center space, unfolds making the part and whole by overlap and continuation. The 2nd Froebel make space decided by the Net and Crystal Lattices which have the crystal characteristics by the rotation. The new geometric architecture, pinwheel, was created by this method. The application of the Froebel in the Wright's works have the several sets which are the 3th, 4th, 5th, 6th Froebels, 2nd, 7th Froebels and the 3th, 5th, 9th Froebels. The geometrical analysis of the square shape and the diagonal shape of the Wright's works was possible. The unfolding of the centered space can be found in the Guggenheim Museum using the analysis of the circular geometric of the 9th Froebel. The above study proves that the Froebel was not a mere tool for the basic shape training but also the main body of Wright's works which consists of the organic idea and philosophy of the space.

The Sense of Outdoor Characteristics on the Shopping Mall Planning -Focusing on Common Space Comparison- (쇼핑몰의 야외성 발현 특성에 관한 연구 -공용공간 비교를 중심으로-)

  • Cho, Hun Hee;Oh, Joon-Gul
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.19 no.3
    • /
    • pp.557-566
    • /
    • 2018
  • Shopping malls have been developed to increase sales revenue and attract visitors. This study focused on the sense of the outdoor characteristics of these shopping malls by comparing open and enclosed types of shopping malls in common spaces in LA and Korea through case study analyses. This research through case studies will form the foundation of comfortable shopping mall space design. The results are the follows. 1. Enclosed shopping malls tend to provide large indoor space to create a sense of outdoors. 2. The common space of enclosed shopping malls is developed through space expansion with horizontal and vertical connections that appear in different combinations depending on the space constraints and contexts. 3. The architectural planning of enclosed shopping malls are largely dependent on the concept of everyday life portrayed in the identity of each space, which usually involve the inclusion of sizable atriums to host indoor sports or special performances.

A Study on Space Program Based on the Library Facility Program (도서관 소요공간에 따른 면적구성에 관한 연구)

  • Ko, Jae-min;Cho, Hyun-Yang;Ko, Hung-Kwon
    • Journal of Korean Library and Information Science Society
    • /
    • v.46 no.3
    • /
    • pp.349-379
    • /
    • 2015
  • In the 1980's opening 79 of the end of 2013, the National Public Library that had been It was 885 its opening remains in effect. Especially in the 2000s after 60% of the whole library, a library erected since the advent of the library is enough to be a significant quantitative expansion. The resulting to make a qualitative aspect of public libraries and increase users' needs for efficient space configuration. IIn particular, the user is to serve the needs of digital reading room and the increase of the cultural training changes after 2000 years ago, and appears as due to the implications of space configuration in an age-appropriate library space off the rate plan is a necessary point. The study in the 1980s-1990s, built public library established since the year 2000 centered on public library mutual comparative analysis of space configuration form. Book reading function was the conservation and highlight 1980-1990s and considered by the side of the users culture area extended since the 2000s, public library takes the difference between the ratio of the area of the facility by the area in which you can meet the standards required and the age.

An Ultrastructral changes of the new-born rats and adult rat's cornea (신생 흰쥐와 성숙 흰쥐 각막의 미세구조 변화에 관한 연구)

  • Kim, Dae Nyoun;Kim, In Suk
    • Journal of Korean Ophthalmic Optics Society
    • /
    • v.3 no.1
    • /
    • pp.93-101
    • /
    • 1998
  • The present study was conducted to investigate the structural changes in rat cornes. Sixty eyes from one-day-old uneyed rats, fourty eyes from 10-weeks-old adult rats were used. With the increase of age, the epithelial layer was thickened by the addition of new successive cellular layers. Then, the new-born rat's epithelial cells formed a pentagonal shape, and the quality of decidual cells showed a high electron-density, although the boundary between cells was distinctive. The newly produced cells showed a low electron-density so that there was the distinctive difference between light and darkness. In Bowman's layer, collagen fibrils demonstrate a regularly arranged structure along with the age. In stroma's layer, the density of keratocytes was decreased and thereby progressively flattened during the development. The collagenous layer of the adult rats was more distinctive than that of the new-born rats in a form of vertical and horizontal parallel alignment running vertically and horizontally. Descemet's membrane changed its structure significantly along with the age. It changed the shape from "banded-layer" to "non-banded layer" gradually. The thickness was also increased along with the age. Regardless of developmental stages, the endothelium is usually monolayer. During the developmental process, endothelial cells disappeared, so the density of endothelium was also decreased. The empty spaces were replaced by the expansion of adjacent cells.

  • PDF