• The Journal of Asian Finance, Economics and Business
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• 제7권12호
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• pp.195-210
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• 2020

This study describes the structure of the capital markets for small- and medium-sized enterprises (SMEs) and startup companies in Korea, which is an emerging market that has experienced drastic changes. The overall capital market can be divided into private and public capital markets. In the private capital market, most of the demand for capital comes from non-listed private firms, including startups and SMEs. In the case of SMEs and startups, the KOSDAQ, the Korea New Exchange (KONEX), and primary collateralized bond obligations (P-CBOs) are part of the public capital market. SMEs and startups are generally incapable of raising sufficient capital owing to their low credit ratings, and they largely have limited access to primary markets to issue shares and borrow money. The Korean government has developed a systematic financial aid program to provide funds to these companies. The fund for SMEs has significantly contributed to the development of the venture capital market. Many Korean banks provide substantial lending to SMEs, but this lending is available only because of the Korean government's loan recovery guarantee. Furthermore, SMEs can issue corporate debt in the form of primary collateralized bond obligations through government guarantees, but such debt issuances have placed increasing pressure on public guarantee institutions.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2000년도 춘계학술대회 논문집
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• pp.195-201
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• 2000

In this paper propose the new method on desig ESJ(Electrical Separation Joint) of Jointless Track Circuit. ESJ has a capability to saparate track signal electrically but enable connected a track section physically. So It is more proper to high-speed line. Because that demand a critical traveling safety and convient taking a train. In spite of existing ESJ of Jointless Track Circuit, UM7l, S-bond, According to new pole-zero placement and desgining tuining-unit It is possible to prove a independence of track-section and track-signal in new ESJ design of this paper

• 무역상무연구
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• 제58권
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• pp.179-213
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• 2013

While a performance type guarantee is required as a security for non-performance risk by a seller, a payment guarantee is used as a security for non-payment risk by a buyer(or a borrower in a loan agreement). A payment guarantee is a type of independent bank guarantee, bank guarantee, bond, demand guarantee, or standby letter of credit. A guarantor accepts a credit risk of a principal which is normally a buyer in a contract for sale of goods. A payment guarantee is independent of the underlying relationship between the applicant and the beneficiary. The guarantor is only empowered to examine the beneficiary's demand and determine the payment on its face to the terms of the guarantee. A payment guarantee is thus different from a suretyship. The principle of independence carries a significant advantages for a guarantor as well as for a beneficiary. While a documentary credit requires B/L, commercial invoice, packing list, inspection certificate, etc., a typical payment guarantee does not require any evidence for a seller's performance of the underlying contract other than written demand. In this respect payment guarnatee can be a more secured facility than a documentary credit. A payment guarantee normally comes into force from the issuing date and shall remain in effect until all sums guaranteed shall be paid in full by a buyer(or a borrower) or by a guarantor. Although a guarantor shall pay a demand made in accordance with the terms and conditions of the payment guarantee, a payment demand may be denied when it is determined to be abusive or unfair.

• 대한치과교정학회지
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• 제40권1호
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• pp.27-33
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• 2010

성인 교정환자의 수요가 증가하면서 보철물 표면에 교정장치를 부착해야 하는 빈도가 늘어나고 있다. 본 연구는 금속표면에 교정장치를 직접 접착하고자 할 때 사용하는 metal primer와 silicoating으로 각각 금합금의 표면을 처리한 후 light emitting diode (LED) 광중합기를 사용하여 광중합을 시행하여 접착력을 평가해 보고자 하였다. Type III gold alloy 표면에 aluminum oxide를 이용한 sandblasting 후 4-META 계열의 metal primer로 처리한 시편과 silica를 이용한 sandblasting 후 silane으로 처리한 시편에 광중합형 접착레진인 Transbond XT를 이용하여 금속 브라켓을 접착하고 접착 후 1시간, 6시간, 24시간 후 전단접착강도의 변화를 비교, 관찰하였다. 측정된 값을 이원분산분석(two-way analysis of variance)을 이용하여 비교하고 두 가지 표면처리 방법 간에 접착강도에 차이가 있는지도 살펴보았다. 연구결과, metal primer에 비하여 silicoating을 시행한 시편에서 높은 전단접착강도가 관찰되었으며, 시간이 경과할수록 접착강도가 증가하는 경향을 보였다. Adhesive remnant index (ARI)에서는 군 간 유의한 차이를 보이지 않았다. LED를 이용하여 광중합을 시행하는 경우 법랑질에 비하여 긴 시간의 광중합을 실시하고 metal primer보다는 silicoating 방법을 사용하는 것이 금합금표면에 교정장치를 부착할 때 더 높은 접착강도를 얻을 수 있을 것이다.

• 한국건설순환자원학회논문집
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• 제11권1호
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• pp.39-47
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• 2023

최근 구조물의 장대화로 인하여 고강도 재료의 경량화 요구가 빈번해지고 있는 실정이다. 하지만 현재까지는 압축강도 120 MPa, 단위중량 20 kN/m³ 정도의 고강도 경량 콘크리트를 구조부재에 적용하기 위한 콘크리트와 철근의 부착 특성에 관한 연구가 부족한 실정이다. 따라서 본 논문에서는 압축강도 120 MPa, 단위중량 20 kN/m³ 정도의 고강도 경량 콘크리트 108개의 시편을 제작하여 직접 인발 부착실험을 수행하였고, 실험결과와 현행 설계기준과 비교하여 부착특성을 평가하였다. 솔리드버블은 단위중량 감소에 비해서 압축강도 및 탄성계수 감소효과는 상대적으로 적게 나타나, 초경량화를 위해서는 반드시 적용되어야 할 재료로 판단되며, ACI-408R의 부착강도 산정식과 실험결과는 비교적 유사한 것으로 판단되며, 더 낮은 압축강도, 단위중량의 콘크리트보다 더 큰 슬립 및 매개변수 값을 가지는 것으로 나타났다.

• 마이크로전자및패키징학회지
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• 제19권2호
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• pp.29-33
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• 2012

The demand for 3D wafer level integration has been increasing significantly. Although many technical challenges of wafer stacking are still remaining, wafer stacking is a key technology for 3D integration due to a high volume manufacturing, smaller package size, low cost, and no need for known good die. Among several new process techniques Cu-to-Cu wafer bonding is the key process to be optimized for the high density and high performance IC manufacturing. In this study two main challenges for Cu-to-Cu wafer bonding were evaluated: misalignment and bond quality of bonded wafers. It is demonstrated that the misalignment in a bonded wafer was mainly due to a physical movement of spacer removal step and the bond quality was significantly dependent on Cu bump dishing and oxide erosion by Cu CMP.

• Journal of Welding and Joining
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• 제16권5호
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• pp.100-107
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• 1998

This paper describes fluxless soldering of reflow soldering process using solder foil instead of solder pastes. There is an increasing demand for the reliable solder connection in the recent high density microelectronic components technologies. And also, it is problem fracture of an Ozone layer due to freon as which is used to removal of remained flux on the substrate. This paper discussed joining phenomena, boudability and joining processes of microelectronics devices, such as between outer lead of VLSI package and copper pad on a substrate without flux. The shear strength of joints is 8 to 13 N using Sn/Pb (63/37 wt.%) solder foil with optimum joining conditions, meanwhile, in case of using Sn/In (52/48 wt.%) solder foil, it is possible to bond with low heating temperature of 550 K, and accomplish to high bonding strength of 25N in condition heating temperature of 650K. Finally, this paper experimentally shows fluxless soldering using solder foil, and accomplishes key technology of microsoldering processes.

• 대한치과교정학회지
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• 제29권4호
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• pp.445-456
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• 1999

최근에는 교육수준의 향상, 소득증대, 대중매체의 발달 등으로 인하여 성인 교정환자의 수요가 상당히 증가하고 있다. 성인환자는 어린환자에 비해 상대적으로 구강내 도재수복물을 장착하고 있는 경우가 많아 도재치에 대한 교정용 브라켓의 직접접착의 기회도 증가하고 있다. 자연치에서는 법랑질을 산부식하여 비교적 쉽게 접착력을 증진시킬 수 있으나 도재치에서는 임상에서 브라켓이 너무 쉽게 탈락하거나 오히려 도재파절의 위험성이 존재하여 도재치에 대한 효과적인 직접접착법에 대하여 관심을 갖게 되었다. 그러나, 이러한 접착효율에 대한 다양한 연구가 있었으나 아직 정설로 받아들여지는 것은 없는 실정이다. 본 연구는 임상에서 비교적 간단히 이용할 수 있는 몇 가지 방법을 in vitro 상의 실험을 통하여 그 결과를 비교검토하여 효과적인 방법을 제시하고자 시행되었다. 우선 장석형 도재인 Ceramco II로 도재 시편을 제작하였다. 도재의 표면처리방법은 Glazing한 도재 자체를 사용하기 위해서는 무처리하였으며, 거칠기를 부여하기위해서는 불화수소산으로 산부식하거나 Microetcher II로 Sandblasting, 또는 불화수소산과 Sandblasting을 복합처리하였다. 접착레진은 화학중합형 인 Ortho-two와 광중합형인 Transbond를 사용하였다 모든 시편에는 도재 프라이머를 도포하였다. 실험군은 7가지 군으로 나누어 브라켓의 전단강도를 측정하였다. 1. 도재의 표면처리에 대한 비교에서 Ortho-two군내에서는 불화수소산이나 sandblasting으로 표면거칠기를 부여한 군이 무처리군에 비해 높은 전단강도를 갖는다. Transbond군내에서는 각각의 표면처리에 따른 유의성있는 차이가 없었다. 2. 불화수소산이나 Sandblasting처리군에서는 화학중합형 레진인 Ortho-two가 광중합형 레진인 Transbond보다 높은 전단강도를 갖는다. 3. 도재 파절율의 비교에서는 무처리군이 표면거칠기를 부여한 군에 비해 매우 낮은 파절율 갖는다. 4. E(Transbond+Intact)군의 평균전단강도는 134.4kg/$cm^2$ 로 본 실험군중 가장 낮은 것으로 나타났다. 이것은 선학들이 제안한 임상적용가능 전단강도보다 크므로 7가지군 모두 임상적으로 교정력을 가하기 에 충분한 전단강도를 갖는다. 그러나, 도재의 파절율을 고려해볼 때 파절율이 상대적으로 낮은 무처리군이 임상적으로 더 효과적일 것으로 사료된다.

• 한국건축시공학회지
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• 제5권2호
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• pp.123-130
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• 2005

The purpose of this study is to present the optimum performance of hybrid waterproofing technology, which is including material and construction method. Recently, Hybrid waterproofing technology is developed little by little in KOREA. But there is not any other criterion of performance and evaluation of this technology. So, It is needed that appropriate performance items is are settled urgently. This paper were obtained by the SPSS analysis. In this study the safety factor are more important performance of building waterproofing materials than durability comfortability and productivity. And results of this analysis showed that (1) safety performance consists of Fatigue resistance, Crack Control performance deterioration Processing of tensile performance, Compressive Strength test (2) comfortability performance consists of watertightness, bond performance (3) persistency performance consists of abrasion resistance, tensile performance, flexural strength (4) productivity performance consists of dimension, unit space weight.

• 한국토양비료학회지
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• 제48권1호
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• pp.1-7
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• 2015

Global population is expected to reach nine billion in 2050 and the total demand for food is expected to increase approximately by 60 percent by 2050 as compared to 2005. Therefore, it is important to increase crop production in order to meet the global demand for food. Slow release fertilizers have been developed and designed in order to improve the efficiency of fertilizers. Mineral-based slow release fertilizers are useful because the minerals have a crystalline structure and are environmentally friendly in a soil. This review focuses on slow release fertilizers based on montmorillonite, zeolite, and layered double hydroxide phases as a host for nutrients, especially N. Urea was successfully stabilized in the interlayer space of montmorillonite by the formation of urea-Mg or Ca complex, $[(Urea)_6Mg\;or\;Ca]^{2+}$ protecting its rapid degradation in soils. Naturally occurring zeolites occluded with ammonium nitrate and potassium nitrate by molten salt treatment could be used as slow release fertilizer because the occlusion process increased the capacity of zeolites to store nutrients in addition to exchangeable cations. Additionally, surface-modified zeolites could also be used as slow release fertilizer because the modified surface showed high affinity for anionic nutrients such as nitrate and phosphate. Moreover, there were attempts to develop and use synthetic layered double hydroxide as a carrier of nitrate because it has positively charged layers which electrostatically bond nitrate anions. Kaolin was also tested by combining with a polymer or through the mechanical-chemical process for slow release of nutrients.