• Journal of the Microelectronics and Packaging Society
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• v.31 no.3
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• pp.1-9
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• 2024

This paper addresses the significance of Cu/Polymer Hybrid Bonding technology in the advancement of semiconductor packaging. As the demands of the AI era increase, the semiconductor industry is exploring heterogeneous integration packaging technologies to achieve high I/O counts, low power consumption, efficient heat dissipation, multifunctionality, and miniaturization. The conventional Cu/SiO₂ Hybrid Bonding structure faces limitations such as achieving compatibility with CMP processes to attain surface roughness below 1nm and the occurrence of bonding defects due to particles. However, Cu/Polymer Hybrid Bonding technology, utilizing polymers, is gaining attention as a promising alternative to overcome these challenges. This study focuses on the deposition, patterning, and material properties of polymers essential for Cu/Polymer Hybrid Bonding, highlighting the advantages and potential applications of this technology compared to existing methods. Specifically, the use of polymers with low glass transition temperatures (Tg) is discussed for their benefits in low-temperature bonding processes and improved mechanical properties due to their high coefficients of thermal expansion. Furthermore, the study explores surface property modifications of polymers and the enhancement of bonding mechanisms through plasma treatment. This research emphasizes that Cu/Polymer Hybrid Bonding technology can serve as a critical breakthrough in developing high-performance, low-power semiconductor devices within the industry.

• Economic and Environmental Geology
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• v.28 no.6
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• pp.587-597
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• 1995

Two distinct precious-metal mineralizations actively occur at central and southeastern Korea which display consistent relationships among geologic, geochemical and genetic environments. A large number of preciousmetal vein deposits in the central Korea occur in or near Mesozoic granite batholiths elongated in a NE-SW direction. Whereas, gold and/or silver deposits in the southeastern Korea occur within Cretaceous volcanic and sedimentary rocks. However, most of the precious-metal deposits in the southeastern Korea show characteristics of the silver-rich deposits than the gold-rich deposits in the central Korea. Two epochs of main igneous activities are recognized: a) Jurassic Daebo igneous activity between 121 and 183 Ma, and b) Cretaceous Bulgugsa igneous activity between 60 and 110 Ma. Precious-metal mineralization took place between 158 and 71 Ma, coinciding with portions of the two magmatic activities. Contrasts in the style of mineralization, together with radiometric age data and differences in geologic settings reflect the genetically variable natures of hydrothermal activities from middle Jurassic to late Cretaceous time. The compilation and re-evaluation of these data suggest that the genetic types of hydrothermal precious-metal vein deposits in the central and southeastern Korea varied with time. The Jurassic and early Cretaceous mineralizations are characterized by the Au-dominant type, but tend to change to the Au-Ag and/or Ag-dominant types at late Cretaceous. The Jurassic Au-dominant deposits commonly show several characteristics; prominent associations with pegmatites, simple massive vein morphologies, high fmeness values in ore-concentrating parts, and a distinctively simple ore mineralogy such as Fe-rich sphalerite, galena, chalcopyrite, Au-rich electrum, pyrrhotite and/or pyrite. The Cretaceous precious-metal deposits are generally characterized by some- features such as complex vein morphologies, low to medium fmeness values in the ore concentrates, and abundance of ore minerals including Ag sulfosalts, Ag sulfides, Ag tellurides and native silver. Mineralogical and fluid inclusion studies indicate that the Jurassic Au-dominant deposits in the central area were formed at the high temperature (about $300^{\circ}$ to $500^{\circ}C$) and pressure (about 4 to 5 kbars), whereas mineralizations of the Cretaceous Au-Ag and Ag-dominant deposits were occurred at the low temperature (about $200^{\circ}$ to $350^{\circ}C$) and pressure (<0.5 kbars) from the ore fluids containing more amounts of less-evolved meteoric waters.

• Korean Business Review
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• v.13
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• pp.49-66
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• 2000

Despite the fact that understanding customers satisfaction with transportation services is a subject of great importance, authors, so far, found no systematic researches referred to that issue. From this point, studying the satisfaction with subways services can be extremely useful. Empirical study of key factors in the satisfaction with subway services is the departure point, which holds as objectives, and we believe, will contribute to overall increasing in the number of subways services used and in the amount of public benefits derived from that usage. In order to achieve these goals: First, several items referred to some key factors in the satisfaction of subway usage were systemized. Second, a research of specific weights attached to those key factors by subway passengers was conducted. Knowledge of the satisfaction variables system can provide deep insights into ones perceptual experience when using a subway. The results were as follows: Various interrelated factors compose a passengers satisfaction with subway services. People do not just use subway passively; a number of key factors, like physical and personal services, exact timing, easiness to access etc. determine the passengers satisfaction with subway. In order to find out specific weights of these key factors multiple regression analysis was employed. Results showed that satisfaction with subway is determined by (in order of importance) easiness to access, quality of physical services, friendliness of working stuff and timing exactness. According to the findings, passengers do not use subway as a simple mean of transportation, rather they perceive it as a complex combination of environmental elements and overall satisfaction depends on these various factors. Therefore, to learn passengers satisfaction with subways services, passengers subway experience must be thoroughly studied and analyzed, and this is where papers value resides.

• Journal of the Korean Society for Marine Environment & Energy
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• v.13 no.1
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• pp.18-29
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• 2010

Offshore subsurface storage of $CO_2$ is regarded as one of the most promising options to response severe climate change. Marine geological storage of $CO_2$ is to capture $CO_2$ from major point sources, to transport to the storage sites and to store $CO_2$ into the offshore subsurface geological structure such as the depleted gas reservoir and deep sea saline aquifer. Since 2005, we have developed relevant technologies for marine geological storage of $CO_2$. Those technologies include possible storage site surveys and basic designs for $CO_2$ transport and storage processes. To design a reliable $CO_2$ marine geological storage system, we devised a hypothetical scenario and used a numerical simulation tool to study its detailed processes. The process of transport $CO_2$ from the onshore capture sites to the offshore storage sites can be simulated with a thermodynamic equation of state. Before going to main calculation of process design, we compared and analyzed the relevant equation of states. To evaluate the predictive accuracies of the examined equation of states, we compare the results of numerical calculations with experimental reference data. Up to now, process design for this $CO_2$ marine geological storage has been carried out mainly on pure $CO_2$. Unfortunately the captured $CO_2$ mixture contains many impurities such as $N_2$, $O_2$, Ar, $H_{2}O$, $SO_{\chi}$, $H_{2}S$. A small amount of impurities can change the thermodynamic properties and then significantly affect the compression, purification and transport processes. This paper analyzes the major design parameters that are useful for constructing onshore and offshore $CO_2$ transport systems. On the basis of a parametric study of the hypothetical scenario, we suggest relevant variation ranges for the design parameters, particularly the flow rate, diameter, temperature, and pressure.

• Korean Architects
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• no.12 s.344
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• pp.50-50
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• 1997

이번 지역건축을 기획하면서, 여러 가지 상념에 잠기게 되었다. 건축에서 지역성이 어느 정도 내재되어 있는지 살펴보고자 하는 것이 혹시 더욱 부정적 결과를 확인하는 것이라면 이를 확인할 필요가 있을지, 또 어떤 긍정적 결과를 확인할 수 있을지, 게다가 여러 개발도상국의 상황과 아시아의 건축적 진행을 보면서, 어쩌면 우리는 더욱 난감한 상황을 보게 될지도 모른다. "건축을 발전시켜온 어떤 민족도 각기 독자적 언어, 복장, 민속이 있는 것처럼, 그들이 좋아하는 형태를 발전시켜왔다. 19세기에 문화의 국경이 붕괴될 때까지 온 세계의 건축에는 지역고유의 형태와 디테일이 있었다. 그리고 어떠한 지역특유의 건물도 사람들의 창조력과 그 지역의 필요성의 결합에 의하여 태어난 아름다운 산물이었다. 그러나 현대 이집트에는 이집트 고유의 토착양식을 찾아볼 수가 없다. 바로 이집트인의 서명이 없다. 그것이 부자들의 집이건 가난한 자의 집이건 무성격하기는 마찬가지이며 이집트인의 자취란 사라져 버렸다."(하산 화티,1973년) 선진국은 스스로 산업혁명을 일으켰고, 이런 사회적 문화적 변동에 적응하기 위하여 1세기 이상의 시간적 여유가 있었다는 것이다. 개발도상국의 급속한 변화에는 건물도 변화의 수단으로 이용되었다는 것이다. "민족적이며, 지역적인 전통이야말로, 새로운 지역주의의 기초로서 보존하고 사용되어야 된다는 '섬세한' 서양의 관찰자들의 탄원은 이같은 상황에서는 전연 고려되지 않았다."고 커티스는 보았다. 섬세한 서양인이 아니라 자국민 스스로 자신의 문명에 대하여 파괴적인 입장에 서 있다면 더욱 난감한 일이다. 지역주의의 의미는 무엇일까? 건축에서 '지역'의 범주는 어디인가? 인종적 분포 또는 민족적 무리를 이름지은 것인가? 아니면 인종과 민족의 공통점인가? 그것도 아니라면 정치적 경계선으로 둘러싸인 경계를 말하는 것인가? 모든 지역이 다 지역주의로 대별될 수 있는가? 어느 곳이 건축에서의 중심지역이며, 또 지역주의는 누가 판별하는가? 프램튼은 문화적인 중심지와 종속적 관계를 지니는 지역주의를 잘못된 구조로 보았다. 근래 10년간 세계적으로 다양한 지역주의가 대두했다. 지역의 개념적, 제도적, 법적인 상태가 어떠한가가 중요한 요인이 된다. 19세기 동안에 유럽사람들이 그들의 정치적 독립을 위한 목적에 활용하기 위하여 부분적으로 거짓된 역사관을 피력했을 때, 유럽지역에서의 지역주의 개념들은 아이리쉬, 까딸로니아, 핀랜드 등을 평가하는 역할이 있었다고 한다. 지역주의를 "감상적인 민족적 편견에서 비롯된 광신적 배타주의"라고 낮추어 바라보는 그로피우스의 시각에 대해, 당당히 맞설 수 있어야 할 것이다. 리꾀르의 말대로 미래에 어떠한 유형의 참된 문화를 유지하는 것은 궁극적으로는 문화나 문명의 단계에서 외래의 영향을 적절하게 하면서 지역문화의 활기찬 형태를 발생시키는 우리 능력에 달려있다. '지역적' 범위는 서구에서 합중국으로 존재하는 경우, 대부분 이질적 문화들의 혼합지역이기 때문이다. 한국과 같이 비교적 단일한 성분의 종족으로 한 국가가 유지된 경우와 미국과 같이 다양한 종족이 모인 경우 등과 비교하면 '지역'이란 이름에 어떤 판단기준이 있어야 할까? 근래 지역적 변동이 적었던 한국의 경우는 상대적으로 재론할 여지가 적다. 그러나 한국의 역사시대 내에서도 확인되지 않은 부분들이 존재하고, 역사시대의 범위를 넘어서 선사시대로 확대하면 '지역'의 개념의 외연적 대상은 더욱 모호해진다.

• The Journal of the Korea Contents Association
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• v.20 no.6
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• pp.38-50
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• 2020

The purpose of this study is to identify the risks to financial institutions in terms of expanding potential risks due to the deferral of exposure, by identifying the structures in which real estate finance and financial institutions affect real estate prices at low interest rates. To this end, real estate financing is categorized according to the method of financing and the type of value measurement from a risk management perspective and analyzed for each case. As a result of analysis, in the case of profitable real estate, the rate of real estate is increased by directly decreasing the cap rate and directly affecting the fair value calculation method. In the case of non-profitable real estate, the real estate price is increased by expanding the leverage width of investors or financial institutions. Through the analysis of this case, the continuous increase in real estate prices over the past 10 years has the potential to prevent financial institutions from losing under the circumstances such as the growth of real estate finance due to the advancement of the financial market and the continued low interest rate trend that has continued for 10 years. It is judged that the deferred delay is part of the cause, which leads to an increase in the risk to financial institutions.

• Journal of the Korea Concrete Institute
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• v.18 no.1 s.91
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• pp.3-12
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• 2006

The behavior of concrete structures subject to fire is complex, depending on many factors. The factors usually considered in research include the level and endurance of temperatures in concrete and reinforcing bars, the mechanical properties of the steel and concrete, moisture contents, cover thickness, existence of eccentricity, and member geometry among others. Although there are a few sophisticated numerical models which can trace the effects of these important parameters on the residual capacity of reinforced concrete columns damaged by fire, practical predictive formulas are in need for rapid yet reasonable assessment in practice. The practical formulas are developed in this study for fire-damaged normal strength reinforced concrete square columns, which can approximate the predictions of those sophisticated numerical models with ease in use. The formulas take into account the effects of exposure time to fire, concrete strength, reinforcement ratio and sectional area. The developed formulas are seen to correlate with the predictions of numerical model in a reasonable agreement. Some examples are also presented in determining the residual strength, safety and additionally needed strengths for a fire-damaged reinforced concrete column.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.105.2-105.2
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• 2011

화비정질 실리콘의 빛에 의한 노화현상 (light-induced degradation; LID)은 이미 1977년 보고된 Staebler-Wronski 효과에 의해서 확인된 바 있다. 이는 비정질 실리콘이 빛에 노출될 때, 이미 포함되어 있는 수소원자가 빛 에너지에 의해서 이동하게 되고, 이로 인해서 생성 또는 소멸되는 댕글링 본드 때문에 일어난다. 특히, 일상적인 태양광의 노출 하에서 태양전지의 장시간 성능을 예측하는데 물리적인 이해의 부족 및 기술 환경적인 어려움이 있고, 이러한 요인들은 안정된 태양전지를 개발하는데 장해요인으로 나타난다. 그러므로 비정질 실리콘 태양전지가 장시간 태양광에 노출되어 시간이 지남에 따라서 "성능이 어떻게 변하는지?" 그리고 "이에 대한 원인은 무엇인지?" 등은 여전히 과학적으로 풀어야할 숙제로 남아있다. 본 논문에서는 비정질 실리콘으로 구성된 태양전지가 태양광에 노출될 때 시간이 지남에 따라서 (1) 성능이 어떻게 변하는지, (2) LID의 변화는 언제 안정화되는지, 그리고 (3) 성능변화에 대한 원인은 무엇인지에 대해서 논의한다. 본 논문은 장시간 빛에 노출되는 비정질 실리콘 태양전지의 성능예측에 관해서 연구하였다. 결함밀도의 운동학적 모형을 통해서 태양광 노출에 대한 태양전지 성능변화를 예측하는데 초점을 맞추었고, 이를 위해서 태양전지에 조사되는 태양광 세기, 주변온도, 등이 고려되었다. 특히, 전하운반자의 수명이 결함밀도에 의해서 결정되기 때문에 비정질 실리콘 태양전지의 빛에 대한 노화현상 (LID)이 확장지수함수 (stretched-exponential) 완화법칙을 따르는 결함밀도에 의해서 물리적으로 설명된다. 한편 이와 같은 물리적 계산의 유용성을 확인하기 위해서 동일한 태양전지에 대해서 AMPS-1D 컴퓨터 프로그램을 사용하였고, 이를 통해서 비정질 실리콘 태양전지의 빛에 대한 노화현상을 물리적 및 정량적으로 이해하였다. 본 연구에 적용되는 태양전지는 비정질 실리콘으로 구성된 pin 구조 (glass/$SnO_2$/a-SiC:H:B/a-Si:H/a-Si:H:P/ITO)로서 다음과 같은 특성을 갖는다: 에너지 띠간격~1.72 eV, 두께~400 nm, 내부전위~1.05 V, 초기 fill factor~0.71, 초기 단락전류~16.4 mA/$cm^2$, 초기 개방전압 0.90 V, 초기 변환효율 10.6 %. 우리는 이와 같은 연구를 통해서 과학적으로 비정질 실리콘의 빛에 의한 노화현상을 이해하고, 기술적으로 효율 및 경제성이 높은 태양전지의 개발에 도전한다.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.8
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• pp.492-497
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• 2015

VOCs (Volatile Organic Compounds) are generally generated in the painting process, or at the company and laundry where use organic solvents. The VOCs consist of various hydrocarbons and has low calorific value due to its dilution with atmospheric air. Therefore, the VOCs are difficult to burn by a conventional fuel combustor. In this study, a novel plasma dump combustor was proposed for the treatment of low calorific VOC gases. This combustor was designed a combination of the characteristics in a plasma burner, a dump combustor and a 3D matrix burner. The combustor has good structure for maintaining enough residence time and reaction temperature for stable flame formation and VOC destruction. For investigating the performance characteristics of the plasma dump combustor, an experiment was achieved for VOC feed rate, VOC injector position, etc. Toluene was used as a surrogate of VOC. The novel combustor gave better performance than a conventional combustor, showing that VOC destruction rate and energy efficiency were 89.64% and 12.27 kg/kWh respectively, at feeding rate of 450 L/min of VOC of 3,000 ppm of toluene concentration.

• Applied Biological Chemistry
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• v.41 no.1
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• pp.6-12
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• 1998

To extract insoluble proteins and to improve functional properties of abolished proteins, a protease producing Aspergillus sp. MS-18 was isolated from soil. The enzyme was purified and its enzymological characteristics were investigated. It was found that production of protease reached to the maximum when the wheat brae medium containing, 3% arabinose, 0.5% polypepton, 0.1% $(NH_4)_2SO_4$ and 0.2% magnesium chloride was cultured for 3 days. Protease was purified 16.9 folds after ion exchange chromatography and gel filtration and the specific activity was 340.4 unit/mg. Purified enzyme was confirmed as a single band by the polyacrylamide gel electrophoresis. The molecular weight of protease was estimated to be 30,000. Crystalization form of purified protease was a stick shape with rounding edges. The optimum pH and temperature for the protease activity were 9.0 and $60^{\circ}C$, respectively. The enzyme was stable in pH 7.0-12.0 at $50^{\circ}C$. The activity of purified enzyme was inhibited by $Hg^{2+}$, $Cu^{2+}$, $Zn^{2+}$ and $Pb^{2+}$, whereas it was activited by $Na^+$, $Mg^{2+}$ and $Mn^{2+}$. The activity of the protease was inhibited by the treatment with ethylenediaminetetraacetic acid and phenylmethane sulfonyl fluoride. The result suggests that the purified enzyme is a serine protease with metal ion at active site. Km and Vmax of purified protease were $29.33\;{\mu}mole/L$ and $5.13\;{\mu}g/min$, respectively.