• Journal of Korean Society for Geospatial Information Science
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• v.12 no.3 s.30
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• pp.51-59
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• 2004

In the study, there has been a sharp upward trend in road maintenance cost as the expansion of road networks increases. Running a pavement management system(PMS) is indispensable for efficient and scientific maintenance of the whole road networks with limited maintenance budgets. With a PMS, a maintenance plan should be drawn up after surface conditions are precisely examined and analyzed. The majority of the present PMSs are run by the fact that experts first examine surface conditions on sites, and then enter results into systems. However, considering the actual circumstances of the present time and the increase in paved road hereafter, it is inefficient that experts examine the whole paved roads in person and long-lasting PMSs can not be kept up. As a result, after analyzing the accuracy of 3-D coordinates representing road surfaces that was decided using multi orientation and digital photogrammetry, the average of standard errors turned out to be 0.0427m on the X-axis, 0.0527m on the Y-axis and 0.1539m on the Z-axis. It was found to be good enough to be put to practical use for maps drawn on scales below 1 :1000, which are being currently made and used within the country, and GIS data.

• The Journal of the Korea Contents Association
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• v.11 no.2
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• pp.22-30
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• 2011

In the IT convergence environment changed with not only the quality but also the material abundance, it is the most crucial factor for the strategy of personalized recommendation services to investigate the context information. In this paper, we proposed the recommendation using the service ontology based context awareness modeling. The proposed method establishes a data acquisition model based on the OSGi framework and develops a context information model based on ontology in order to perform the device environment between different kinds of systems. In addition, the context information will be extracted and classified for implementing the recommendation system used for the context information model. This study develops the ontology based context awareness model using the context information and applies it to the recommendation of the collaborative filtering. The context awareness model reflects the information that selects services according to the context using the Naive Bayes classifier and provides it to users. To evaluate the performance of the proposed method, we conducted sample T-tests so as to verify usefulness. This evaluation found that the difference of satisfaction by service was statistically meaningful, and showed high satisfaction.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.10a
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• pp.320-323
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• 2008

Due to the improvement of mobile device capabilities, a demand for various contents service is increasing. But the differences from heterogeneous mobile devices force to develop contents which is dependent on a mobile. To solve this problem, adaptation course that reorganize contents by the device capability is needed. In this course, device description is described using device description language but there are some problems that is absence of device description repository and the way to get device description data. In this paper, I suggest device description acquisition module and define the interfaces to access device description repository that I designed and implemented.

• Korean Journal of Materials Research
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• v.5 no.7
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• pp.869-879
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• 1995

TiAi intermetallic compound has been extensively studied for possible high temperature structural applications because of its high specific strength at high temperature, high creep resistance, and good oxidation resistance at elevated temperatures. In addition to its good properties, an economic manufacturing routes should be developed for this material to be used more extensively. One of the promising route in manufacturing TiAl intermetallics is the Self-propagating High-temperature Synthesis (SHS) method. Thus in this study, an attempt was made to study the mechanism of the SHS process in TiAl synthesis. The composition of the sample was Ti-(45, 50, 53)at% Al and the microstuctures of the products were analyzed using optical microscope and scanning electron microscope. When the phases formed at the main SHS reaction of whicyh combustion temperature is higher than the melting temperature of aluminum were identified as TiAl and Ti$_3$Al ; Ti$_3$Al cores surrounded by TiAl phase. In order to increase the combustion temperature, carbon was added 5 and 10at.%. When the carbon content was 10at.%, the heat of the reaction was large enough to melt the phase formed and that is consistent with the theoretical calculation results of the adiabatic temperature. The combution temperatue, which was measured by a computer data acquisition system, increased with the carbon content. The phases formed from the reaction involving the carbon added were indentified as TiAl and Ti$_2$AlC using XRD. The vickers hardness of the reaction product increased with the carbon content.

• The Korean Journal of Community Living Science
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• v.17 no.2
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• pp.3-14
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• 2006

This study intends to offer suggestions for improving the security and competitive power of traditional liquors by investing in the status of intellectual property rights. Merchandising and the marketing strategies of traditional liquor are also addressed. The data was collected through a questionnaire survey given to 101 CEOs of traditional liquor manufacturers. The major results of this study were as follows: The management types of traditional liquor manufacturers were classified as the company 57 (56.4%), the corporation or the union 29 (28.7%), domestic industry 10 (9.9%), and marketing community or technology center 5 (5.0%). The competitive power degree of traditional liquor products was classified as strength 30 (31.6%), usual 30 (31.6%), weakness 35 (36.8%). The elements of strong competitive power were taste, functional (wellbeing) character, and attractiveness of the brand name. On the other side, reasons for weakness in competitive power were the marketing system, price competitiveness, and advertisement. The trademark registration of the traditional liquor appeared with 53%. The reasons not to pursue a trademark registration included the complicated and unnecessary process of registration acquisition, high registration expenses, etc. The perceptions of CEOs about the consumer's brand awareness for their product were low with an average 2.97. Explanations included insufficient advertisement and public relations, unrefined trademark design, and the meaninglessness of brand names. The marketing strategy of traditional liquor manufacturers according to annual sales were as follows: Manufacturers with high sales emphasized marketing strategies that focused on functional character, traditional image, high quality in image and package materials and design, high price strategies based on quality, and various sale promotions.

• Journal of Biomedical Engineering Research
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• v.31 no.4
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• pp.259-268
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• 2010

Breast cancer is the most prevalent woman cancer, and its prevalence rate is increasing rapidly. It is necessary to develop the breast-dedicated positron emission tomography (PET) or positron emission mammography (PEM) systems with high resolution and sensitivity to improve the accuracy of diagnosis of breast cancer. Therefore, it is necessary to develop the high-end PET system technologies, such as the measurement of depth-of-interaction (DOI) and fully digitalized data acquisition, to establish high performance breast imaging systems. In this paper, recent technical advances in breast-dedicated PET imaging systems will be reviewed.

• Journal of radiological science and technology
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• v.28 no.4
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• pp.273-277
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• 2005

The rapid development in digital acquisition technology in radiography has not been accompanied by information regarding optimum radiolographic technique for use with an amorphus silicon flat panel detector. The purpose of our study was to compared image quality and radiation dose of an amorphus silicon flat panel detectors for digital chest radiography. All examinations were performed by using an amorphus silicon flat panel detector. Chest radiographs of an chest phantom were obtained with peak kilovoltage values of $60{\sim}150kVp$. Published data on the effect of x-ray beam energy on image quality and patient dose when using an amorphus silicon flat panel detector. It is important that radiographers are aware of optimum kVp selection for an amorphus silicon flat panel detector system, particularly for the commonly performed chest examination.

• Transactions of the Korean Society of Mechanical Engineers
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• v.10 no.6
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• pp.823-829
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• 1986

The Large-scale structure of the circular jet in the transition region, which influences the subsequent flow in the turbulent region, was studied experimentally. Measuring equipments are composed of the two channel hot-wire anemometer, the computer controlled two-directional traverse mechanism, the data acquisition system, and FFT-analyzer. The circular jet has 50mm diameter. The mean velocity distribution, the velocity fluctuation, the auto 'cross correlations and the power spectra were acquired at moderate Reynolds number of 10$^{4}$. And the VITA method was used to measure the convection velocity of Large-scale eddy. The phase of u'is in advance of that of v'in all regions. .over bar. $R_{u}$(.tau.=0) is approximately zero in the potential core region, but a small regular deviation is observed. At a position in the mixing layer region the convection velocity is different along the part of the eddy, and in this experiment the convection velocity of the inner region is larger than the outer region. The averge convection velocity of the eddy along y/D=0 was approximately constant in the transition region.D=0 was approximately constant in the transition region.

• Journal of the Korean Society for Nondestructive Testing
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• v.37 no.1
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• pp.13-20
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• 2017

A conventional phased array ultrasonic system offers the ability to steer an ultrasonic beam by applying independent time delays of individual elements in the array and produce an ultrasonic image. In contrast, full matrix capture (FMC) is a data acquisition process that collects a complete matrix of A-scans from every possible independent transmit-receive combination in a phased array transducer and makes it possible to reconstruct various images that cannot be produced by conventional phased array with the post processing as well as images equivalent to a conventional phased array image. In this paper, a basic algorithm based on the LLL mode total focusing method (TFM) that can image crack type flaws is described. And this technique was applied to reconstruct flaw images from the FMC dataset obtained from the experiments and ultrasonic simulation.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.883-888
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• 2007

일반적인 하천의 흐름방향으로 발생하는 주흐름(primary flow)에 중첩하여 주흐름 방향의 수직단면에 이차류(secondary flow)가 발생하게 되며 이러한 이차류의 발달은 투입된 오염물질의 횡혼합을 증대시킨다. 오염물질의 혼합은 이송(advection)과 확산(diffusion) 또는 분산(dispersion)의 과정으로 설명되며 본 연구에서는 수로전체의 혼합과정을 설명하기 위해서 이송 확산 방정식을 적용하였다. 본 연구에서는 실험수조를 $150^{\circ}$의 중심각을 갖는 S자 형태의 만곡수로를 제작하여 유량조건은 15, 30, $60\;{\ell}l/sec$의 세 가지 경우로, 수심은 15, 20, 30, 40 cm의 경우로 총 12 케이스의 실험을 수행하였다. 유속장의 측정은 Sontek사의 3차원 micro-ADV(Acoustic Doppler Velocimeter)를 이용하였다. 오염물질 확산실험은 소금물 용액에 주변수와의 밀도차를 없애기 위해서 메탄올 용액을 첨가하여 추적자로 이용하여 농도장의 분석을 일본 KENEK사의 전기전도도계(conductivity meter)와 Gartner사의 DAS(data acquisition system)를 이용하여 횡방향 유속장의 분포와 오염운의 거동을 비교하여 다음과 같은 결론을 얻게 되었다. 주 흐름은 직선구간에서는 중앙에서 최대 유속을 나타내며, 좌우대칭적인 유속분포의 모습을 보이고, 만곡부에서는 수로안쪽을 따라 최대유속이 발생하였다. 수로의 직선구간에서는 최대유속이 발생하는 즉, 중앙에서의 오염물질의 분산이 가장 활발하게 이뤄졌으며 농도의 퍼짐형상인 오염운 역시 만곡부에서는 수로만곡부의 안쪽을 따라 확산 이동함을 알 수 있었다. 만곡부 외측에서는 오염물질의 정체현상이 일시적으로 발생하며, 유속구조의 횡방향 비대칭구조로 인한 종 횡방향의 분리현상이 발생하고, 오염운의 중첩현상이 종방향으로 연속되게 나타난다. 향후 수심방향 거동을 포함한 3차원적 분석이 요구되며 이 연구결과는 2차원적 수치해석의 적용 및 분석 자료로써 이용이 가능하다.