• Journal of Microbiology and Biotechnology
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• v.16 no.1
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• pp.141-144
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• 2006

An antibody layer was fabricated to detect Escherichia coli O157:H7. The micropattern of 16-mercaptohexadecanoic acid (16-MHDA) as alkylthiolate was formed on the gold surface by using the PDMS stamp with microcontact printing $({\mu}CP)$ techniques. In order to form antibody patterns on the template, protein G was chemically bound to the 16-MHDA patterns, and antibody was adsorbed on a self-assembled protein G layer. The formation of the 16-MHDA micropattern, self-assembled protein G layer and antibody pattern on Au substrate was confirmed by surface plasmon resonance (SPR) spectroscopy. Finally, the micropatterning method was applied to fabricate the antibody probe for detection of E. coli O157:H7, and monitoring of antigen by using this probe was successfully achieved.

• Bulletin of the Korean Chemical Society
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• v.24 no.2
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• pp.209-218
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• 2003

Ecosystems in the Keweenaw Peninsula region of Lake Superior, USA, were disturbed by over 500 million tons of copper-rich mine tailings during the period 1850-1968. Metals leaching from these mine residues have had dramatic effects on the ecosystems. Vast acreages of exposed tailings that are over 100 years old remain unvegetated because of the combination of metal toxicity, absence of nutrients, and temperature and water stress. Therefore, it is important to characterize and fractionate solid copper phases for assessing labile forms of copper in soils and sediments contaminated by the mining wastes. X-ray diffraction analyses indicate that calcite, quartz, hematite, orthoclase, and sanidine minerals are present as major minerals, whereas cuprite,tenorite, malachite, and chalcopyrite might be present as copper minerals in the mining wastes. Sequential extraction technique revealed that carbonate and oxide fractions were the largest pools of copper (ca. 50-80%) in lakeshore and wetland stamp sands whereas the organic matter fraction was the largest reservoir (ca. 32%) in the lake sediments. The concentrations of iron and copper were inversely correlated in the oxide fraction suggesting that copper may occur as a surface coating on iron oxides. As particle size and water contents decrease, the percent of the copper bound to the labile carbonate fraction increases.

• Journal of the Korea Institute of Military Science and Technology
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• v.8 no.4 s.23
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• pp.58-67
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• 2005

To overcome limitations of test scope, schedule and cost, M&S(Modeling & Simulation) technique has been applied for T&E(Test and Evaluation) of the state-of-art weapon systems. This paper proposes an air defense simulation software framework to reduce both redundancy an[1 programming errors in system simulator. The proposed framework consists of a 'model' and a 'middleware' The 'middleware' is a reliable communication service layer that supports not only HLA(High Level Architecture) which is an international standard in M&S but also TCP/IP, UDP and etc. The main role of 'model' is to schedule and to run the real-time distributed simulation. The proposed framework has been applied to M-SAM(Middle range Surface to Air Missile) system simulator. The proposed framework's scheduling and communication performance results are satisfactory and were measured by hardwired NTP(Network Timer Protocol) time-stamp with GPS(Global Positioning System) timer for better precision.

• Proceedings of the Materials Research Society of Korea Conference
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• 2010.05a
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• pp.31.1-31.1
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• 2010

Various ZnO nanostructures were synthesized and ZnO nanostructure-based self-assembled transistors were fabricated. Compared to spindle and flower like nanostructure, the ZnO nanorod (NR) structure showed much stronger gate controllability, and greatly enhanced device performance, demonstrating that this structural variation leads to significant differences of the nanostructure network-based device performance. Also, patterned dry transfer-printing technique that can generate monolayer-like percolating networks of ZnO NRs has been developed. The method exploits the contact area difference between NR-NR and NR-substrate, rather than elaborate tailoring of surface chemistry or energetic. The devices prepared by the transferring method exhibited on/off current ratio, and mobility of ${\sim}2.7{\times}10^4$ and ${\sim}1.03\;cm^2/V{\cdot}s$, respectively. Also, they exhibited showing lower off-current and stronger gate controllability due to defined-channel between electrodes and monolayer-like network channel configuration. With multilayer stacks of nanostructures on stamp, the monolayer-like printing can be repeated many times, possibly on large area substrate, due to self-regulating printing characteristics. The method may enable high-performance macroelectronics with materials that have high aspect ratio.

• Journal of the Korean Ceramic Society
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• v.52 no.2
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• pp.108-113
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• 2015

In an effort to evaluate the practicability of an imprinting technique for amorphous chalcogenide film in Ge-based compositions, we investigate the deformation behavior of the surface of amorphous $GeSe_2$ film deposited via a thermal evaporation route according to varying static loads applied at elevated temperatures. We observe that, under these static loading conditions, crystallization tends to occur on its surface relatively more easily than in As-based $As_2Se_3$ films. As for the present $GeSe_2$ film, higher processing temperatures are required in order to make its surface reflect the given stamp patterns well; however, in this case, its surface becomes partially crystallized in the monoclinic $GeSe_2$ phase. The increased vulnerability of this amorphous $GeSe_2$ film toward surface crystallization under static loading, when compared with the $As_2Se_3$ counterpart, is explained in terms of the topological aspects of its amorphous structure.

• Korean Journal of Optics and Photonics
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• v.17 no.1
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• pp.99-103
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• 2006

A tunable wavelength filter was proposed and demonstrated by using the UV nanoimprint technique. It consists of a Bragg grating in polymer waveguides and a heating electrode. The manufacturing of the grating was substantially simplified with the introduction of a smart imprint stamp containing a waveguide pattern integrated with the grating pattern. The center wavelength of the filter was successfully tuned by taking advantage of the thermooptic effect in polymers, which was induced by supplying electrical power to the electrode. For the fabricated device, a transmission dip of ${\~}$15 dB and a 3-dB bandwidth of 0.8 nm were obtained at the Bragg wavelength of ${\~}$l560 nm. The achieved thermooptic tuning efficiency was ${\~}$0.28 nm/mW, while the center wavelength was shifted from 1560 nm to 1558 nm with the electrical power consumption of 7 mW.

• Journal of KIISE:Software and Applications
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• v.26 no.8
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• pp.974-987
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• 1999

이동 컴퓨팅 환경에서 자주 접근하는 데이터에 대한 캐싱은 무선 채널의 좁은 대역폭에서 경쟁을 줄일 수 있는 유용한 기술이다. 그러나, 트랜잭션 캐시 일관성을 지원하는 전통적인 클라이언트/서버 전략은 클라이언트와 서버간에 많은 양의 통신을 필요로 하기 때문에 이동 클라이언트/서버 컴퓨팅 환경에서는 적절하지 않다. 본 논문에서는 브로드캐스트-기반 캐시 무효화 정책을 사용하면서 트랜잭션 캐시 일관성을 지원하는 OCC-UTS (Optimistic Concurrency Control with Update TimeStamp) 프로토콜을 제안한다. 접근한 데이터에 대한 일관성 검사 및 완료 프로토콜은 캐시 무효화 과정의 내부 과정으로 완전 분산 형태로 효율적으로 구현되며, 일관성 체크의 대부분이 이동 클라이언트에서 수행된다. 또한, 분석 모델에 기반한 성능 비교를 통해, 본 논문에서 제안하는 OCC-UTS 프로토콜이 다른 경쟁 프로토콜보다 높은 트랜잭션 처리율을 얻으며, 데이터 항목을 자주 접근하면 할수록 지역 캐시를 사용하는 OCC-UTS 프로토콜이 더 효율적임을 보인다. 이동 클라이언트의 접속 단절에 대해서는 무효화 브로드캐스트 윈도우를 크게 하여 접속 단절에 적절히 대처할 수 있다.Abstract In a mobile computing environment, caching of frequently accessed data has been shown to be a useful technique for reducing contention on the narrow bandwidth of the wireless channels. However, the traditional client/server strategies for supporting transactional cache consistency that require extensive communications between a client and a server are not appropriate in a mobile client/server computing environment. In this paper, we propose a new protocol, called OCC-UTS (Optimisitic Concurrency Control with Update TimeStamp), to support transactional cache consistency in a mobile client/server computing environment by utilizing the broadcast-based solutions for the problem of invalidating caches. The consistency check on accessed data and the commitment protocol are implemented in a truly distributed fashion as an integral part of cache invalidation process, with most burden of consistency check being downloaded to mobile clients. Also, our experiments based on an analytical model substantiate the basic idea and study the performance characteristics. Experimental results show that OCC-UTS protocol without local cache outperforms other competitor protocol, and the more frequent a mobile client accesses data items the more efficient OCC-UTS protocol with local cache is. With respect to disconnection, the tolerance to disconnection is improved if the invalidation broadcast window size is extended.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.4
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• pp.201-209
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• 2012

The point-based complex event processing handled an instantaneous event by using one time stamp in each event. However, the activity period of the event plays the important role in the field which is the same as the finance, multimedia, medicine, and meteorology. The point-based event is insufficient for expressing the complex temporal relationship in this field. In the application field of the real-time world, the event has the period. The events more than two kinds can be temporally overlapped. In addition, one event can include the other event. The relation about the events of kind of these can not be successive like the point-based event. This thesis designs and implements the method detecting the patterns of the complex event by using the interval-based events. The interval-based events can express the overlapping relation between events. Furthermore, it can include the others. By using the end point of beginning and end point of the termination, the operator of interval-based events shows the interval-based events. It expresses the sequence of the interval-based events and can detect the complex event patterns. This thesis proposes the algorithm using the active instance stack in order to raise efficiency of detection of the complex event patterns. When comprising the event sequence, this thesis applies the window push down technique in order to reduce the number of intermediate results. It raises the utility factor of the running time and memory.

• Journal of KIISE:Software and Applications
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• v.27 no.2
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• pp.108-119
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• 2000

Most of prior works on testing parallel programs have concentrated on how to guarantee the reproducibility by employing event traces exercised during executions of a program. Consequently, little work has been done to generate meaningful event sequences, especially, from specifications. This paper describes techniques for deriving event sequences from Message Sequence Charts(MSCs) which are widely used in telecommunication areas for its simplicity in specifying the behaviors of a program. For deriving event sequences from MSCs, we have to uncover the causality relations among events embedded implicitly in MSCs. In order to attain this goal, we adapt vector time stamping which has been previously used to determine the ordering of events taken place during an execution of interacting processes. Then, valid event sequences, satisfying the causality relations, are generated according to the interleaving rules suggested in this paper. The feasibility of our testing technique was investigated using the phone conversation example. In addition, we discussed on the experimental results gained from the example and how to combine various test criteria into our testing environment.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.48 no.1
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• pp.72-79
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• 2011

The importance of parallel programming seriously emerges ever since the modern microprocessor architecture has been shifted to the multi-core system. Transactional Memory has been proposed to address synchronization which is usually implemented by using locks. However, the lock based synchronization method reduces the parallelism and has the possibility of causing deadlock. In this paper, we propose an efficient method to utilize transactional memory for the situation which has high contention. The proposed idea is based on the theoretical analysis and it is verified with simulation results. The simulation environment has been implemented using HTM(Hardware Transactional Memory) systems. We also propose a model of the dining philosopher problem to discuss the efficient resource management using the transactional memory technique.