• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.5
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• pp.532-538
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• 2004

MEMS technology applying to the sensors and micro-electro devices is complete system. These microsystems are made by variable processes. Especially, the mentallization process has very important functions to transfer the power operating the sensor and signal induced from sensor part. But in the structures of MEMS the local stress concentration and deformation are often yielded by an irregular geometrical shape and different constraint. Therefore, this paper studies the effect of supporting type and thickness ratio about thin film of the substrate on the residual stress variation when the thermal loads is applied to the multi-layer thin film fabricated by metallization process. Specimens were made from several materials such as Al, Au and Cu. Then, uniform thermal load was applied, repeatedly. The residual stress was measured by FE Analysis and nano-indentation method using AFM. Generally, the specimen made of Al induced the larger residual stress than that of made of other materials. Specimen made of Cu and Au having the low thermal expansion coefficient induces the minimum residual stress. Similarly, the lowest indentation length was measured by nano-indentation method in the Si/Au/Cu specimen. Particularly, clusters are created in the specimen made of Cu by thermal load and the indentation length became increasingly large by cluster formation.

• International Journal of Precision Engineering and Manufacturing
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• v.8 no.2
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• pp.75-79
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• 2007

This paper describes the self-alignment and bonding of microparts using adhesive surface tension to assemble microsystems in air. The alignment and bonding were tested experimentally using adhesive droplets, and the resulting performance was evaluated. The adhesive, which was inorganic and water-soluble before hardening, was diluted with water to a ratio of 10:1 so that its surface tension generated a sufficient restoring force for self-alignment. The experimental results showed that the average of the alignment errors obtained using the adhesive on $1.0\times1.0\times0.15-mm$ microparts was less than $2{\mu}m$ in the X and Y directions and 0.2 degrees in the e direction. These alignment errors were almost the same as those obtained using water. The use of a suitable adhesive had no negative effects on the alignment accuracy. The average tensile strength of the adhesive bond after self-alignment was $0.61N/mm^2$.

• Journal of Sensor Science and Technology
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• v.19 no.3
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• pp.209-213
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• 2010

This paper describes the fabrication and characteristics of AlN piezoelectric MPG(micro power generator). The micro energy harvester was fabricated to convert ambient vibration energy to electrical power as a AlN piezoelectric cantilever with Si proof-mass. To be compatible with CMOS process, AlN thin film was grown at low temperature by RF magnetron sputtering and micro power generators were fabricated by MEMS technologies. X-ray diffraction pattern proved that the grown AlN film had highly(002) orientation with low value of FWHM(full width at the half maximum, $\theta=0.276^{\circ}$) in the rocking curve around(002) reflections. The implemented harvester showed the $198.5\;{\mu}m$ highest membrane displacement and generated 6.4 nW of electrical power to $80\;k{\Omega}$ resistive load with $22.6\;mV_{rms}$ voltage from 1.0 G acceleration at its resonant frequency of 389 Hz. From these results, the AlN piezoelectric MPG will be possible to suitable with the batch process and confirm the possibility for power supply in portable, mobile and wearable microsystems.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2004.05b
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• pp.717-720
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• 2004

Jini is a middle ware supposed in Sun Microsystems. The goal of lil is the establishment of dynamic distributed system, which can share information and control of other Jini technology-enabled services or devices in the same Jini system. Jini is one of the best middleware together UPnP and HAVi. Hone network security, soch as privacy protection, crime prevention, and etc, is very important. So Jini 2.0 adds security mechanism in 11. 2003. This paper describes the analysis of Jini 2.0 security mechanism, and home network security.

• Proceedings of the KIEE Conference
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• 2003.11c
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• pp.384-387
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• 2003

In this paper, we have designed the integrated wire and wireless P2P framework using mobile agents to share efficiently resources as media file. Most of the P2P applications are used on the wire network. We propose the integrated wire and wireless P2P framework. Proposed P2P platform is based on JXTA of Sun Microsystems. But JXTA is pure peer-to-peer network model, so it sends message other peers as broadcast style to request resources. In this way, there are some problems as massage overload, bandwidth loss, etc. In order to solve this problem, we propose a hybrid peer-to-peer network model using mobile agent. Proposed scheme also solve existing hybrid pEp model's flaws which have the delay and low rate due to concentrated server. In proposed scheme, mobile agents that have autonomy and mobility are used to search the location of resources. Besides, mobile agents could solve the loss problem of the search result. To improve P2P QoS(Quality of Service), we could monitor peer's state information using PIP(Peer Information Protocol) of JXTA.

• Proceedings of the Korea Multimedia Society Conference
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• 2004.05a
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• pp.199-202
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• 2004

데이터 방송은 지상파, 위성, 케이블 둥의 방송망을 이용하여 하나의 송신자가 다수의 수용자에게 디지털 멀티미디어 컨텐츠를 여러 종류의 단말기에 전송하는 것으로 컨텐츠는 프로그램에 연동되는 서비스 및 비연동형 서비스, 또는 대화형 서비스 헝태로 제공되는 다양한 서비스를 포함한다. 방송망을 이용한 데이터방송의 전송 규약은 DSM-CC에서 정의한 캐로셀(carousel) 형태로 전송된다. 캐로셀은 주기적으로 반복 전송되는 데이터 모듈을 가리키며, 캐로셀로 전송되는 데이터 중에는 MPEG-2 비디오로 인코딩되어 광고와 배경 이미지 등으로 사용할 수 있는 영상 데이터가 있다. 이 MPEG-2 비디오 영상 데이터를 TV화면에 출력하기 위해 셋톱박스의 미들웨어는 썬 마이크로시스템즈(Sun Microsystems)에서 만든 자바 기반의 JMF(Java Media Framework) 플레이어를 통해 화면에 출력한다 이렇게 제공되는 MPEG-2 비디오 영상 데이터를 비디오 드립(drips)이라 하고, 비디오 드립을 JMF 플레이어를 통해 화면에 출력하는 모드를 드립피드(drip-feed) 모드라 한다. 그러나 MHP용 셋톱박스를 위한 JMF 버전 1.0은 그대로 사용 할 수 없다. 비디오 드립 모드를 위한 구현이 없기 때문에 별도의 확장을 통해 비디오 드립을 지원하거나, 네이티브(Native) 메소드를 만들어 JMF를 확장하는 방식을 제공해야 한다. 본 논문에서는 데이터 캐로셀로 전송되는 비디오 드림 모드를 구현하기 위해 네이티브 코드로 JMF를 확장해서 비디오 드립을 JMF 플레이어를 통해 TV 화면에 출력하는 MPEG-2 비디오 드립 디코더를 설계하고 구현하였다.

• International Journal of Stem Cells
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• v.17 no.1
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• pp.30-37
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• 2024

The lung is a complex organ comprising a branched airway that connects the large airway and millions of terminal gas-exchange units. Traditional pulmonary biomedical research by using cell line model system have limitations such as lack of cellular heterogeneity, animal models also have limitations including ethical concern, race-to-race variations, and physiological differences found in vivo. Organoids and on-a-chip models offer viable solutions for these issues. Organoids are three-dimensional, self-organized construct composed of numerous cells derived from stem cells cultured with growth factors required for the maintenance of stem cells. On-a-chip models are biomimetic microsystems which are able to customize to use microfluidic systems to simulate blood flow in blood channels or vacuum to simulate human breathing. This review summarizes the key components and previous biomedical studies conducted on lung organoids and lung-on-a-chip models, and introduces potential future applications. Considering the importance and benefits of these model systems, we believe that the system will offer better platform to biomedical researchers on pulmonary diseases, such as emerging viral infection, progressive fibrotic pulmonary diseases, or primary or metastatic lung cancer.

• Journal of Korea Spatial Information System Society
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• v.1 no.2 s.2
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• pp.5-20
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• 1999

Recently, the new software paradigm in information technology (IT) is the component-based development (CBD) technology that has brought as a result of the distributed computing environment (DCE). The CBD has reduced a program developing time and has been designed to make a distributed computing environment easier in the Internet and Intranet environments. These changes of software technology have influence on the geographic information system (GIS) and the CBD technology is highly needed as a point of view of the technique and policy of the geographic information system. In this paper, we designed and implemented an Enterprise Server for the efficient development and management of GIS components. Especially, the Enterprise Server was developed with the Enterprise JavaBeans Specification 1.1 that had been proposed as an industry standard by the Sun Microsystems. The Enterprise Server can allows users to manage the Unified Modeling Language (UML) and Design Patterns for the development of GIS components, develop a GIS component container which obeyed the Open Geodata Interoperability Specification (OpenGlS), manage spatial metadata through a spatial XML (eXtensible Markup Language) engine, and implement a TESTBED server for testing and verification of developed GIS components.

• The Journal of the Korea Contents Association
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• v.10 no.7
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• pp.122-132
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• 2010

As a result of a growing demand for various mobile devices, the demand for application programs on the devices is on the rise. The Java language that is platform-independent rapidly rose as the best programming language for mobile devices. However, the Java has a problem that does not support platform-dependent features needed by the application. To solve this problem, the JNI technology was introduced by Sun Microsystems. Programmers using the JNI to write native methods need to have a lot of knowledge about the JNI and the internal structure of the JVM. Also, the increased load by using a number of JNI functions may decrease software productivity and quality. Demands for tools writing native method without understanding of JNI are progressively increasing. To develop these tools, it is necessary to translate automatically the differences between Java and C/C++. In this study, I suggested a way to overcome differences between both languages and developed JNI editor that is an integrated develope environment on the basis of this.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.4
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• pp.714-719
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• 2009

Recently, RESTful web service is getting attention with the emergence of Web 2.0. The main advantages of REST web services are lightweight and easy implementation compared to SOAP based web services. In order to define and describe RESTful APIs, various methods have proposed. WSDL 2.0 can describe both SOAP-based and RESTful services and but it is too complicated. WADL is championed by Sun Microsystems and it is lightweight, easier to understand and easier to write than WSDL. The purpose of WADL is to allow web services to be described in a machine readable way, to make it easy to create Web 2.0 applications and create a dynamic way of creating and configuring services. However, WADL does not provide utility tools to generate client code automatically and the developers describe client code manually. In this paper, we design and implement a WADL2Stub system to generate client code from WADL files automatically so that the developers use REST web services to easily and conveniently.