• Title/Summary/Keyword: interface state

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How is Scientific and Technological Knowledge Linked in Technological Innovation in Korea? (우려나라 기술혁신에서의 과학-기술 지식연계 특성분석)

  • Park, Hyun-Woo;Son, Jong-Ku;You, Yeon-Woo
    • Journal of Korea Technology Innovation Society
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    • v.14 no.1
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    • pp.1-21
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    • 2011
  • Technical change and technological innovation have become major drivers of economic progress in the knowledge oriented economies where growth, productivity, and competitiveness are increasingly based on improved technologies, novel products, upgraded processes or customized services. The creation of new knowledge, modifying or improving existent knowledge, or imitation of others, has become central to economic development. New discoveries, state-of-the-art information gathering procedures, or successful problem solving routines are often at he core of these innovations. Despite the generally acknowledged importance of science in many high-tech areas of major economic relevance, there is few science-related statistics to be found in high-profile international benchmarking reports. This paper aims to provide an answer by advancing our understanding of the possibilities of indicators quantifying linkages between science and technology. Central are the concepts of innovation capability and science/technology interface, which are used to assemble a wide range of empirical studies and quantitative indicators to summarize their possibilities and limitations for producing comparative statistics. For the purpose of the study, we extracted the US patents by Korean assignees or inventors, scientific papers cited in the patents in order to analyze the characteristics of linkage of scientific knowledge flows. The review focuses on indicators dealing with flows of written or codified information, and indicators of inventiveness that capture the non-codifiable tacit knowledge dimension. General conclusions will be drawn with a view towards further developments in the foreseeable future, suggesting new avenues for the design and implementation of patent-based and inventor-based relationships between scientific research and technical development within the context of regional or national systems of innovation.

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Interfacial Reaction between 42Sn-58 Bi Solder and Electroless Ni-P/Immersion Au UBM during Aging (시효 처리에 의한 42Sn-58Bi 솔더와 무전해 Ni-P/치환 Au UBM 간의 계면 반응)

  • Cho Moon Gi;Lee Hyuck Mo;Booh Seong Woon;Kim Tae-Gyu
    • Journal of the Microelectronics and Packaging Society
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    • v.12 no.2 s.35
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    • pp.95-103
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    • 2005
  • The interfacial reaction between 42Sn-58Bi solder (in wt.$\%$ unless specified otherwise) and electroless Ni-P/immersion Au has been investigated before and after thermal aging, with a focus on formation and growth of an intermetallic compound (IMC) layer, consumption of under bump metallurgy (UBM), and bump shear strength. The immersion Au layer with thicknesses of 0 (bare Ni), 0.1, and $1{\mu}m$ was plated on the $5{\mu}m$ thick electroless Ni-P ($14{\~}15 at.\%$P) layer. Then, the 42Sn-58Bi solder balls were fabricated on three different UBM structures by screen-printing and pre-reflow. The $Ni_3Sn_4$ layer (IMC1) was formed at the joint interface after pre-reflow for all the three UBM structures. On aging at $125^{\circ}C$, a quaternary phase (IMC2) was observed above the $Ni_3Sn_4$ layer in the Au-containing UBM structures, which was identified as $Sn_{77}Ni{15}Bi_6Au_2$ (in at.$\%$). The thick $Sn_{77}Ni{15}Bi_6Au_2$ layer deteriorated the integrity of the solder joint and the shear strength of the solder bump was decreased by about $40\%$ compared with non-aged joints.

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Nexus based Quality Inspection Support Model for Defect Prevention of Architectural Finishing Works (하자예방정보 넥서스 기반 건축마감공사 품질점검 지원 모델)

  • Lee, Hye-Rin;Cho, Dong-Hyun;Park, Sang-Hun;Koo, Kyo-Jin
    • Korean Journal of Construction Engineering and Management
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    • v.18 no.5
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    • pp.59-67
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    • 2017
  • At the completion of the construction, various finishing processes are concentrated. This imposes a burden on the on-site manager and imposes on experience based quality control, thereby causing deviations in the quality of construction depending on supervisor or worker's individual competence. In addition, the information related to quality control is frequently scattered in various types of documents such as specifications and drawings, and checkpoints are frequently omitted. It is necessary to provide a tool that can effectively provide the practitioner before or during the inspection work by systematically storing the information related to the defect prevention and linking them in a mutually referential state. This paper proposes an quality inspection support model that can systematically store necessary information on activity or room basis for the quality check of the apartment house finishing work. Establish a defect prevention information base and a information nexus by linking specifications, design standards, checklists, regulations, defect cases, and drawings to the finishing process and the rooms. Based on this, information registration and search interface are presented. It can contribute to securing a certain level of construction quality or more by suggesting a frame that can be utilized by linking various defects prevention information with the focus on closing activity and room.

Physical Properties and Electrical Conductivity of PAN-based Carbon Fiber Reinforced Paper (PAN계 탄소섬유 강화 종이의 물리적 특성 및 전기전도도)

  • Jang, Joon;Lee, Chang-Ho;Park, Kwan-Ho;Ryu, Seung-Kon
    • Korean Chemical Engineering Research
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    • v.44 no.6
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    • pp.602-608
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    • 2006
  • Carbon fiber (CF) reinforced papers using polyacrylonitrile (PAN) based CF and wood pulp were prepared by varying the lengths and the concentrations of CF, and the basis weight of paper to investigate adhesive state between CF and pulp, and physical properties and electrical conductivity of the paper. The reinforcement was caused by physical entanglement and adhesion at the interface of the different fibers rather than by chemical bonds. The tear strength and the thickness of the paper increased as increasing the concentration of CF, while the tensile and the burst strength of the paper decreased. The improved dispersion of CF in the paper was obtained from mixing shorter CF, but the maximum electrical conductivity of the paper was gained from mixing 10 mm chopped CF. The electrical conductivity of the paper increased sharply from 2 wt% to 8 wt% of CF showing S-curve, and increased linearly as increasing the basis weight of the paper. Therefore, in order to improve the electrical conductivity and the physical property of the paper, the increase of basis weight of the paper is also important as the increase of CF content in the paper.

Characteristics of LSC coated Metallic Interconnect for Solid Oxide Fuel Cell (LSC가 코팅된 고체산화물 연료전지용 금속연결재의 특성 연구)

  • Pyo, Seong-Soo;Lee, Seung-Bok;Lim, Tak-Hyoung;Park, Seok-Joo;Song, Rak-Hyun;Shin, Dong-Ryul
    • Korean Chemical Engineering Research
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    • v.48 no.2
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    • pp.172-177
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    • 2010
  • This study reports the high-temperature oxidation kinetics, ASR(area specific resistance), and interfacial microstructure of metallic interconnects coated with conductive oxides in oxidation atmosphere at $800^{\circ}C$, The conductive material LSC($La_{0.8}Sr_{0.2}CoO_3$, prepared by Solid State Reaction) was coated on the Crofer22APU. The contact behavior of coating layer/metal substrate was increased by sandblast. The electrical conductivity of the LSC coated Crpfer22APU was measured by a DC two probe four wire method for 4000hr, in air at $800^{\circ}C$. Microstructure and composition of the coated layer interface were investigated by SEM/EDS. These results show that a coated LSC layer prevents the formation and growth of oxide scale such as $Cr_2O_3$ and enhances the long-term stability and electrical performance of metallic interconnects for SOFCs.

Fabrication and Characteristics of Infrared Photodiode Using Insb Wafer with p-i-n Structure (p-i-n 구조의 InSb 웨이퍼를 이용한 적외선 광다이오드의 제조 및 그 특성)

  • Cho, Jun-Young;Kim, Jong-Seok;Son, Seung-Hyun;Lee, Jong-Hyun;Choi, Sie-Young
    • Journal of Sensor Science and Technology
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    • v.8 no.3
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    • pp.239-246
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    • 1999
  • A highly sensitive photovoltaic infrared photodiode was fabricated for detecting infrared light in $3{\sim}5\;{\mu}m$ wavelength range on InSb wafer with p-i-n structure grown by MOCVD. Silicon dioxide($SiO_2$) insulating films for the junction interface and surface of photodiode were prepared using RPCVD because InSb has low melting point and evaporation temperature. After formation of In ohmic contacts by thermal evaporation, the electrical properties of the photodiode were characterized in dark state at 77K. A product of zero-bias resistance and area($R_0A$) showed $1.56{\times}10^6\;{\Omega}{\cdot}cm^2$ that satisfied BLIP(background limited infrared photodetector) condition. When the photodiode was tested under infrared light, the normalized detectivity of about $10^{11}\;cm{\cdot}Hz^{1/2}{\cdot}W^{-1}$ was obtained. we successfully fabricated a unit cell with InSb IR array with good quantum efficiency and high detectivity.

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Evaluation of Deformation Characteristics and Vulnerable Parts according to Loading on Compound Behavior Connector (복합거동연결체의 하중재하에 따른 변형 특성 및 취약부위 산정)

  • Kim, Ki-Sung;Kim, Dong-wook;Ahn, Jun-hyuk
    • Journal of the Society of Disaster Information
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    • v.15 no.4
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    • pp.524-530
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    • 2019
  • Purpose: In this paper, we construct a detailed three-dimensional interface element using a three-dimensional analysis program, and evaluate the composite behavior stability of the connector by applying physical properties such as the characteristics of general members and those of reinforced members Method: The analytical model uses solid elements, including non-linear material behavior, to complete the modeling of beam structures, circular flanges, bolting systems, etc. to the same dimensions as the design drawing, with each member assembled into one composite behavior linkage. In order to more effectively control the uniformity and mesh generation of other element type contact surfaces, the partitioning was performed. Modeled with 50 carbon steel materials. Results: It shows the displacement, deformation, and stress state of each load stage by the contact adjoining part, load loading part, fixed end part, and vulnerable anticipated part by member, and after displacement, deformation, The effect of the stress distribution was verified and the validity of the design was verified. Conclusion: Therefore, if the design support of the micro pile is determined based on this result, it is possible to identify the Vulnerable Parts of the composite behavior connector and the degree of reinforcement.

Development of Hardware for the Architecture of A Remote Vital Sign Monitor (무선 체온 모니터기 아키텍처 하드웨어 개발)

  • Jang, Dong-Wook;Jang, Sung-Whan;Jeong, Byoung-Jo;Cho, Hyun-Seob
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.7
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    • pp.2549-2558
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    • 2010
  • A Remote Vital Sign Monitor is an in-home healthcare system designed to wirelessly monitor core-body temperature. The Remote Vital Sign Monitor provides accuracy and features which are comparable to hospital equipment while minimizing cost with ease-of-use. It has two parts, a bandage and a monitor. The bandage and the monitor both use the Chipcon2430(CC2430) which contains an integrated 2.4GHz Direct Sequence Spread Spectrum radio. The CC2430 allows Remote Vital Sign Monitor to operate at over a 100-foot indoor radius. A simple user interface allows the user to set an upper temperature and a lower temperature that is monitored with respect to the core-body temperature. If the core-body temperature exceeds the one of two defined temperatures, the alarm will sound. The alarm is powered by a low-voltage audio amplifier circuit which is connected to a speaker. In order to accurately calculate the core-body temperature, the Remote Vital Sign Monitor must utilize an accurate temperature sensing device. The thermistor selected from GE Sensing satisfies the need for a sensitive and accurate temperature reading. The LCD monitor has a screen size that measures 64.5mm long by 16.4mm wide and also contains back light, and this should allow the user to clearly view the monitor from at least 3 feet away in both light and dark situations.

A Java Distributed Batch-processing System using Network of Workstation (워크스테이션 네트워크를 이용한 자바 분산 배치 처리 시스템)

  • Jeon, Jin-Su;Kim, Jeong-Seon
    • Journal of KIISE:Computing Practices and Letters
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    • v.5 no.5
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    • pp.583-594
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    • 1999
  • With the advance of VLSI and network technologies, it has now become a common practice to deploy a various forms of distributed computing environments. A study shows that a lot of network-aware computers are in an idle state for considerable amount of time depending on the types of users and time frames of the day. If we can take the full advantage of those idle computers, we can obtain the enormous combined processing power without further costly investment. In this paper, we present a distributed batch-processing system, called the Java Distributed Batch-processing System (JDBS), which allows us to execute CPU-intensive, independent jobs across a pool of idle workstations on top of extant distributed computing environments. Since JDBS is implemented using a Java programming language, it not only extends the scope of machine types that can be joined to the pool, but makes it a lot easier to build an entire system. Besides, JDBS is scalable and fault-tolerant due to its multi-cluster organization and intelligent strategies. A graphical user interface is also provided to facilitate the registration and unregistration, job submission, and job monitoring.

Behavior Evaluation of Thin Bonded Continuously Reinforced Concrete Overlay on Aged Jointed Concrete Pavement(2) (노후 줄눈 콘크리트 포장 보수를 위한 얇은 연속 철근 콘크리트 덧씌우기 포장의 거동 평가(2))

  • Ryu, Sung-Woo;Cho, Yoon-Ho
    • International Journal of Highway Engineering
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    • v.12 no.4
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    • pp.101-110
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    • 2010
  • In this paper, it has been studied about the CRCO to maintain or rehabilitate the aged JCP. The CRCO and JCO was constructed at useless section of Seo-Hae-Ahn express highway in South Korea. The performance evaluation was conducted. Especially, it was focused on the roll of longitudinal reinforced steels inserted into the CRCO. On crack survey results from field construction section, the reflection cracks at joint of the existing pavement occurred in CRCO. However, due to the constraints of longitudinal reinforced steels, crack width was small. Total crack length and quantity in the CRCO more than that in the JCO. And crack spacing in the CRCO was narrower than it in the CRCP. Through the bonding strength test results, if the cold milling and cleaning as well as surface treatment is applied, there will be no debonding problem at interlayer in the early age. From analysis of the horizontal behavior at the joint, the longitudinal reinforced steels constrained crack width which became wider than initial state over time. Also, that steel in the CRCO reduced the horizontal movement due to temperature variation(4 times than that in the JCO). But, if interface is debonded, the roll decreased. Vertical VWG data showed that CRCO did not occur debonding problem at steel location, but there was some problem in JCO. It was confirmed by field coring. The tensile strain appeared in the CRCO, But the compressive strain occurred in the JCO in early age. Through the FWD test result, deflection in the CRCO was less than that in the JCO. And K value in the CRCO was greater than it in the JCO.