• Transactions of Materials Processing
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• v.27 no.1
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• pp.37-47
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• 2018

In this paper, a double spot welding process, utilizing electric resistance heating dies, is suggested for the spot welding of dissimilar metal plates for drawing and concurrent spot welding. This double welding process has two heating methods for the fusion welding at the interfacial zone between steel and aluminum plates, such as heating method by thermal conduction of electric resistance by welding current induced to heating dies, and heating method by electric resistance between contacted surfaces of two plates by welding current induced to copper electrode. This double welding process has welding variables such as each current induced in heating dies and in copper electrode, outer diameters of heating dies, and edge shape of copper electrode. Experiments for current conditions in welding process should be demanded in order to get successful welding strength. It was known that the welding strength could be reached to the value demanded on industry fields under such welding conditions as heating dies of outer ring dia.12mm contacted on steel plate, as heating dies of outer ring dia. 14mm contacted on aluminum plate, and as copper electrode of dia. 6.0mm, and as 3 times continuous heating method by $1^{st}$ current of 11 kA(9cycle), $2^{nd}$ current 11 kA(60cycle), $3^{rd}$ current 7 kA(60cycle) applied in steel heating dies and copper electrodes, flat edge of copper electrode, for double spot welding process of dissimilar metal plates of steel and aluminum of 1.0 mm thickness.

• Journal of Korea Foundry Society
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• v.14 no.6
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• pp.558-565
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• 1994

The horizontal continuous casting process with the heated mold was applied to obtain the unidirectionally solidified rods($4{\sim}8mm$ dia.) of pure copper with good surface quality. The results could be summarized as follows. 1. The unidirectional solidification of pure copper rods with good surface(mirror surface) quality could be obtained by placing the S/L interface inside the heated mold cavity even though the cast copper rods were covered with thin copper oxide layer. 2. The casting speed for 4mm dia. rods with mirror surfaces was affected significantly by the mold-cooler distance rather than the cooling flow rate when other casting conditions were fixed. 3. The casting speed was the main factor affecting the oxidation of copper during the continuous casting and the thickness of copper oxide layer decreased almost linearly as the casting speed increased.

• Proceedings of the IEEK Conference
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• 2003.07d
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• pp.1475-1478
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• 2003

When multimedia contents are adapted to different terminals in the ubiquitous computing environment, the contents' modalities can be converted variously. In this paper, we present an efficient user preference that enable user to specify his choices on the modalities of the adapted contents. We also propose the methods to systematically integrate the user preference into the content adaptation process. This modality conversion preference has been developed as a description tool for MPEG-21 Digital Item Adaptation (DIA).

• Journal of Welding and Joining
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• v.12 no.3
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• pp.101-108
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• 1994

The horizontal continuous casting process with the heating mold was adopted for fabricating defect-free 4043 Al alloy rods of 3.2m dia. with mirror surfaces. These rods were drawn into 2.4mm dia. rods for GTAW welding. The GTAW welding tests were carried out by use of these welding rods with 6061 Al alloy as a base metal. After welding, the X-ray tests, tensile strength tests, bending tests, and microstructural analysis of welded zone and HAZ were carried out. The results represented that the welding rods with good surfaces and welding properties could be made by the horizontal continuous casting, and followed by the drawing process.

• Journal of The Institute of Information and Telecommunication Facilities Engineering
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• v.1 no.2
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• pp.50-57
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• 2002

This paper has been studied the adaptation technique for color vision variations in the MPEG-21 Digital Item Adaptation (DIA). As color is more widely used to carry visual information in the multimedia content, ability to perceive color plays a crucial role in getting visual information. DIA is performed respectively for severe color vision deficiency (dichromats) and for mild color vision deficiency (anomalous trichromats), according to the description of user characteristics about color vision variations. Adapted images are tested by simulation program for color vision variations so as to recognize the appearance of the adapted images in the color deficient vision. Experimental result shows that proposed adaptation technique works well in the MPEG-21 framework.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2002.11a
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• pp.139-143
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• 2002

1990 년대 후반부터 다양한 디지털 통신망을 이용하여 멀티미디어 컨텐츠 서비스가 가능하게 되었다. 하지만, 멀티미디어 컨텐츠의 전달 및 이용을 위한 기반 구조들의 독자적 발전 및 다양한 통합적 관리 체계 시스템으로 인해, 멀티미디어 컨텐츠 표현 방식의 호환성 문제, 혼재하는 네트워크 전달 방식과 단말 방식의 호환성 문제 등의 잠재적인 문제점이 발생한다. 이런 문제의 대안으로 현재 존재하는 기술 및 기반 구조들 사이의 연동을 통한 큰 프레임워크인 MPEG-21이 진행 중이다. MPEG-21 의 목표는 표준화 목표를 구체화하는 것부터 진행하여, 최종적으로 “다양한 네트워크 환경과 단말기에 있어서, 투명하고 통합적으로 멀티미디어 자원의 이용을 가능하게 하는 것”이다. 본 논문에서는 현재 표준화 작업이 진행 중인 MPEG-21 을 기반으로 하는 Testbed를 제안한다. Testbed는 server, client, DIA(Digital Item Adaptation) 의 세 모듈로 구성된다. Server 의 역할은 멀티미디어 컨텐츠를 Digital Item(DI)으로 생성하고, client 가 DI를 요구할 경우 DIA 모듈을 통해서 변환된 DI를 client 에게 제공한다. DIA 모듈은 server 에서 동작되며 client로부터 요청된 DI를 분석하고 client로부터 전송된 환경 정보를 이용하여 client 환경에 적합하게 변환된 (adapted) DI를 생성하는 것이 주 기능이다. Client 는 server 에 저장되어 있는 DI를 선택하고 user preference, terminal capability 등의 필요한 정보를 server로 전송한다. Testbed 에서는 스포츠 경기의 동영상, 정지 영상, 경기 내용 역사를 기록한 파일 등의 DI를 이용한다. 표현 언어는 XML이며, HTTP 기반의 Web 환경에서 구동되도록 설계된다.스템 사이에 의미 있는 데이터 전송, 지식 획득을 위해 정보 기술 분야에서 활용해야 할 영역으로 XML Web Services, Multi-agent Systems, 전문가 컴뮤니티를 위한 그룹웨어 연구 개발에 관해 사례 중심으로 발표한다.다 신선한 공기를 넣어 주었을 때는 배의 발달이 많이 늦어져 배양 3주째에 다른 처리보다 배의 수가 훨씬 적었다. 체세포배가 발달하는 동안에는 산소를 많이 요구하지 않으나 성숙하는 동안에는 산소를 많이 요구하는 것으로 생각된다.적인 것으로 나타났다. 다만, 곡선형은 물론 직선형에서도 열교환 튜브의 배치밀도, 튜브 길이 및 두께 등의 변화에 따른 최적화 연구가 수반되어야 할 것으로 판단된다.에서 제공된 API는 객체기반 제작/편집 도구에 응용되어 다양한 멀티미디어 컨텐츠 제작에 사용되었다.x factorization (NMF), generative topographic mapping (GTM)의 구조와 학습 및 추론알고리즘을소개하고 이를 DNA칩 데이터 분석 평가 대회인 CAMDA-2000과 CAMDA-2001에서 사용된cancer diagnosis 문제와 gene-drug dependency analysis 문제에 적용한 결과를 살펴본다.0$\mu$M이 적당하며, 초기배발달을 유기할 때의 효과적인 cysteamine의 농도는 25~50$\mu$M인 것으로 판단된다.N)A(N)/N을 제시하였다(A(N)=N에 대한 A값). 위의 실험식을 사용하여 헝가리산 Zempleni 시료(15%$S_{XRD}$)의 기본입자분포로부터 %$S_{XRD}$를 계산한 결과, 16%$S_{XRD}$의 결과값을 얻을 수 있었다. 따라서, 본 연구에서 도출한 관계식들이 유효함을 확인할 수 있었다.계식들이 유효함을 확인할 수 있었다.할 때 약간의 증가

• Proceedings of the KOSOMBE Conference
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• v.1997 no.05
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• pp.216-219
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• 1997

We are developing a portable multipurpose gamma counting and imaging probe that will be useful for many applications in nuclear medicine including radioimmunoguided surgery in the detection and treatment of malignant tumors. Any diagnostic information provided by CT, MRI, PET, SPECT or gamma camera imaging prior to surgery obviously is very important, but current techniques are limited in many instances. To overcome some of these limitations, the portable multipurpose gamma probe is being developed. The gamma probe consists of NaI(Tl) crystal with 1" dia $\times$ 0.5" thick and singlechannel photomultiplier tube (SC-PMT) for counting, and 3" dia $\times$ 0.375" and multichannel photomultiplier tube (MC-PMT) for imaging, nuclear instrument module (NIM), position circuits, interface, and PC. The energy resolution using Tc-99m was measured as 14% and the spatial resolution using 3mm dia green LED was measured as 2.9mm. These priliminary results indicate that the currently developing probe is very promising and could be very useful for many applications in nuclear medicine.

• ETRI Journal
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• v.27 no.4
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• pp.341-354
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• 2005

The adaptation of video according to the heterogeneous and dynamic resource constraints on networks and devices, as well as on user preferences, is a promising approach for universal access and consumption of video content. For optimal adaptation that satisfies the constraints while maximizing the utility that results from the adapted video, it is necessary to devise a systematic way of selecting an appropriate adaptation operation among multiple feasible choices. This paper presents a general conceptual framework that allows the formulation of various adaptations as constrained optimization problems by modeling the relations among feasible adaptation operations, constraints, and utilities. In particular, we present the feasibility of the framework by applying it to a use case of rate adaptation of MPEG-4 video with an explicit modeling of adaptation employing a combination of frame dropping and discrete cosine transform coefficient dropping, constraint, utility, and their mapping relations. Furthermore, we provide a description tool that describes the adaptation-constraint-utility relations as a functional form referred to as a utility function, which has been accepted as a part of the terminal and network quality of service tool in MPEG-21 Digital Item Adaptation (DIA).

• Journal of Environmental Health Sciences
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• v.23 no.3
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• pp.102-108
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• 1997

It has been studied that SO$_2$ removal efficiency of anthracite-bituminous coal blend combustion in a fludized bed coal combustor. The objectives of this study were to investigate SO$_2$ removal characteristics of coal blend combustion with Ca/S, anthracite fraction, bed temperature, and limestone size. The experimental results were presented as follows First, the effect of the desulfurization by the dia size of limestone was great and SO$_2$ removal efficiency was highest in limestone dia 631 $\mu$m. Second, as air velocity increased, the desulfurization rate decreased a little. But the difference of the desulfurization rate according to air velocity was not too large. As the height of fluidized bed combustor increased regardless of air velocity, SO$_2$ concentration tends to increase largely. Third, as Ca/S mole ratio incresed, SO$_2$ desulfurization rate incresed rapidly up to Ca/S mole ratio 3 while the desulfurization rates did not increse too largely in the range of more than the level. Forth, the bed temperature had a great effect on the desulfurization rate and the desulfurization rate tended to increase slightly as anthracite fraction increased.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2008.11a
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• pp.189-192
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• 2008

Modern broadcasting/multicasting networks has the heterogeneous nature in terms of terminals and available bandwidth. Such heterogeneity could be coped by scalable video coding (SVC) standard developed recently. More specifically, spatial layers of an SVC bitstream can be consumed by different terminals and SNR (and temporal) scalability can be used to cope with bandwidth heterogeneity. In this work, we tackle the problem of SVC adaptation for different user groups receiving the same broadcast/multicast video, so as to provide a flexible tradeoff between the groups while also maximizing the overall quality of the users. The adaptation process to truncate an SVC bitstream is first formulated as an optimization problem. Then the problem is represented by MPEG-21 DIA description tools, which can be solved by a universal processing. The results show that MPEG-21 DIA is useful to enable automatic and interoperable adaptation in our scenario.