• Journal of the Semiconductor & Display Technology
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• 제5권2호
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• pp.33-36
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• 2006

Many issues arose to use the Pb-free solder as adhesive materials in MEMS ICs and packaging. Then this study for easy and simple sealing method using adhesive materials was carried out to maintain hermetic characteristic in MEMS Package. In this study, Hermetic characteristic using negative PR (XP SU-8 3050 NO-2) as adhesive at the interface of Si test coupon/glass substrate and Si test coupon/LTCC substrate was examined. For experiment, the dispenser pressure was 4 MPa and the $200\;{\mu}m{\Phi}$ syringe nozzle was used. 3.0 mm/sec as speed of dispensing and 0.13 mm as the gap between Si test coupon and nozzle was selected to machine condition. 1 min at $65^{\circ}C$ and 15 min at $95^{\circ}C$ as Soft bake, $200\;mj/cm^2$ expose in 365 nm wavelength as UV expose, 1 min at $65^{\circ}C$ and 6 min at $95^{\circ}C$ as Post expose bake, 60 min at $150^{\circ}C$ as hard bake were selected to activation condition of negative PR. Hermetic sealing was achieved at the Si test coupon/ glass substrate and Si test coupon/LTCC substrate. The leak rate of Si test coupon/glass substrate was $5.9{\times}10^{-8}mbar-l/sec$, and there was no effect by adhesive method. The leak rate of Si test coupon/LTCC substrate was $4.9{\times}10^{-8}mbar-l/sec$, and there was no effect by dispensing cycle. Better leak rate value could be achieved to use modified substrate which prevent PR flow, to increase UV expose energy and to use system that controls gap automatically with vision.

• KIEAE Journal
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• 제16권6호
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• pp.167-172
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• 2016

Purpose: The solar water heater with natural circulation has been used for several decades in the world as it is automatically operated without a pump and controller and is easy to maintain and repair. After the subsidy was offered from 2012, the solar water heater with natural circulation is becoming increasingly popular in Korea. Recently, the development of a wall-integrated solar water heater, which improves the applicability of buildings and prevents the overheating in the summer, is being developed. On the other hand, the design and performance evaluation data of solar water heaters are very inadequate, and analysis of heat and flow is required to develop a new type of solar water heater. Method: Therefore, in this study, we proposed a new simplified system analysis model that reflects heat and pressure loss from the test results of KS B ISO 9806-1 (Solar collector test method), assuming that the collector is a simple pipe system, the validity of which was verified through experiments. Result: As a result, first, the RMSE of the system circulation flow rate and the average temperature of the inlet and outlet of the collector according to the experimental results and the simulation are 0.05563 and 0.88530, respectively, which are very consistent. Secondly, the mass flow rate is increased linearly with the increase of the solar radiation, and the mass flow rate is 0.0104 ~ 0.0180kg/s in the range of $200{\sim}380W/m^2$ of solar irradiance. Compared with the test flow rate 0.0764kg / s of the test collector, it showed a level of less than 20%.

• Journal of Families and Better Life
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• 제24권2호
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• pp.137-148
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• 2006

The current study proposesto examine the external appearance types of urban-style hanok in the Bukchon Hanok Preservation District according to their use. For this purpose, we conducted a field survey from the 12th of September to 10th of October 2005, which investigated the location, condition md use of urban-style hanok that were being used for non-residential purposes. The external elevation of the houses were observed and photographed. The results are as follows. First, there were 158 urban-style hanok used for non-residential purposes and200 cases of non-residential use. There were 69 cases of food and beverage spaces, 58 cases of small retail businesses, 38 cases of cultural facilities and 7 cases of convenience facilities. Second, among residential urban-style hanok used for non-residential purposes, 131 cases changed the external appearance of existing urban-style hanok and only 69 cases maintained the original appearance of urban-style hanok or renovated the appearance fittingly to non-residential use. Among the renovated cases, 59 involved the construction of a firewall and 10 cases involved remodeling in a contemporary style. Among the transformed cases, 40 cases exhibited a full opening to the roadside, n involved the change of external appearance components, 14 involved the extension of the courtyard and 12 involved overall improvements to a contemporary style. Third, in the case of cultural facilities and offices, many instances reproduced an urban-style hanok in the traditional style, but small retail shops and food/beverage spaces showed serious deformation. Particularly small retail shops opened the side to the road or extended the courtyard regardless of the location of the houses in order to increase the store space and, as a result, severely damaged the urban-style hanok. In addition, many food/beverage spaces remodeled their external components using tiles, bricks or metals, which were easy to maintain.

• The Journal of Korean Academy of Prosthodontics
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• 제54권4호
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• pp.423-430
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• 2016

The implant prosthesis can be divided into the screw retained prosthesis and cement retained prosthesis. Each type has advantages as well as disadvantages which is unfavorable to maintain the implants. To overcome these drawbacks, T-screw system was developed. T-screw system which utilizes a lingual direction of the screw to retain the implant prosthesis, has advantages of retrievability of the prosthesis, passive fit, and possibility to form esthetic and functional occlusal surface. The prior prosthesis which utilized horizontal screws had difficulty in fabrication especially in the case of multiple units, and also limited use with all-ceramic prosthesis. In this case, fabricating the implant prosthesis by using the T-screw system showed superior results in easy maintenance, esthetics, and also functions. In addition, we are to report the method of using the T-screw system in implant prosthesis, such as multiple units of implant prosthesis and all ceramic prosthesis.

• Journal of Korean Society for Geospatial Information Science
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• 제7권2호
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• pp.133-141
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• 1999

Collapse of a huge structural material has brought about enormous loss of lives and property. Every construction may be destroyed by the nature's power and careless mistake of human as well as its own defect. So a great number of concern and detailed managing technique are demanded not in constructing work but also in management of constructed material. The Interest of construction safety has Increased rapidly and a plenty of effort has been attempted to manage systematically. In this study, the use of FM(Facilities Management) as a branch of GSIS(Geo-spatial Information System) was developed to offer the users convenient managing achievement and establishment of history managing system in the bridge management system. This study accomplished dividing all information of images, photos, drawing and etc. into their items of time, material and the person in charge, and developed to stue and maintain those items in database. Related database which is composed of recording of check, retrieving and adding the data was accomplished to an easy access of database, and by using these data as output for example images, m display, report and hard copy, this system was proved to help manage efficiently in bridge management system.

• The Korean Society of Law and Medicine
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• 제12권2호
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• pp.295-316
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• 2011

If the medical staff privileges, which mean the eligibility to practice at open hospitals, are excluded in the United States, antitrust claims based on the violation of the Sherman Act have been raised a lot. The proliferation of these lawsuits in the United States, which are characterized as antitrust lawsuits, can be understandable situation. The reason is because doctors who don't belong to specific hospitals are seriously damaged, if the medical staff privileges are excluded and doctors cannot use facilities of open hospitals. In order to decide to allow the privileges of certain doctors, hospitals have to rely on peer review to maintain high quality of medical services, and it is not easy to find alternative of peer review in the professional areas like healthcare. However, there are possibilities that members of the peer review can abuse power to unfairly exclude privileges of potential competitors. In this sense, it is asserted in the U.S. antitrust lawsuits that the restraint of medical staff privilege can be the illegal restraint of trade in violation of section 1 of Sherman Act and can be monopolization or an attempt to monopoly by hospitals in violation of section 2 of Sherman Act. As Korea adopted open hospital system quite recently, there is still no case related with the exclusion of medical staff privileges. However, medical staff privilege system of Korea is not different from that of the United States in principle. Thus, the U.S. jurisprudence on the exclusion of medical staff privileges can be referred in the interpretation of "practice that interferes with or restricts the activities or contents of the business" based on Article 19.1.9 of Monopoly Regulation and Fair Trade Law of Korea.

• Proceedings of the Korean Society of Medical Physics Conference
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• 한국의학물리학회 2002년도 Proceedings
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• pp.138-140
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• 2002

The spinal cord dose is the one of the limiting factor for the radiation treatment of the head & neck (H&N) or the thorax region. Due to the fact that the cord is the elongated shaped structure, it is not an easy task to maintain the cord dose within the clinically acceptable dose range. To overcome this problem, the spinal cord partial block technique (PBT) with the dynamic Multi-Leaf Collimator (dMLC) has been developed. Three dimension (3D) conformal beam directions, which minimize the coverage of the normal organs such as the lung and the parotid gland, were chosen. The PBT field shape for each field was designed to shield the spinal cord with the dMLC. The transmission factors were determined by the forward calculation method. The plan comparisons between the conventional 3D conformal therapy plan and the PTB plan were performed to evaluate the validity of this technique. The conformity index (CI) and the dose volume histogram (DVH) were used as the plan comparison indices. A series of quality assurance (QA) was performed to guarantee the reliable treatment. The QA consisted of the film dosimetry for the verification of the dose distribution and the point measurements. The PBT plan always generated better results than the conventional 3D conformal plan. The PBT was proved to be useful for the H&N and thorax region.

• The Journal of the Acoustical Society of Korea
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• 제20권3호
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• pp.56-62
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• 2001

In this paper, we adopt a missing data theory to speech recognition. It can be used in order to maintain high performance of speech recognizer when the missing data occurs. In general, hidden Markov model (HMM) is used as a stochastic classifier for speech recognition task. Acoustic events are represented by continuous probability density function in continuous density HMM(CDHMM). The missing data theory has an advantage that can be easily applicable to this CDHMM. A marginalization method is used for processing missing data because it has small complexity and is easy to apply to automatic speech recognition (ASR). Also, a spectral subtraction is used for detecting missing data. If the difference between the energy of speech and that of background noise is below given threshold value, we determine that missing has occurred. We propose a new method that examines the reliability of detected missing data using voicing probability. The voicing probability is used to find voiced frames. It is used to process the missing data in voiced region that has more redundant information than consonants. The experimental results showed that our method improves performance than baseline system that uses spectral subtraction method only. In 452 words isolated word recognition experiment, the proposed method using the voicing probability reduced the average word error rate by 12％ in a typical noise situation.

• Journal of the Korea Society of Computer and Information
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• 제16권2호
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• pp.47-53
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• 2011

The detection process of defective tags in most of Korean domestic RFID manufacturing companies is treated by on-hand processing after the job of chip bonding, so it has been requested to reduce the time and cost for manufacturing of RFID tags. Therefore, in this paper, we implement the system to perform the detection of defective tags after the process of chip bonding, and so provide the basis of software to establish the foundation of automation system for the detection of defected RFID tags which is requested in the related Korean domestic industrial field. We have developed the system by using UML in modeling phase and JAVA in implementation phase to reduce the cost of development of program and make it easy to maintain. The developed system in this paper shows the very enhanced performance in processing speed and perfect detection rate of defective tags, comparing to the method of on-hand processing.

• Proceedings of the KSR Conference
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.1097-1106
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• 2007

Rail provides running tract for train and broadly and widely conveys the weight of the train exerted from the train wheels that the rail directly supports onto the cross tie and roadbed, and supports the cross-sectional pressure exerted by centrifugal force at curvatures. That is, stationary rail provides surface on which dynamic train runs and guarantees cross-sectional resistance to enable the vertical snake motion of the train wheels as well as to maintain lateral force at curvatures. Rail provides running surface on which train wheels can run smoothly, and secures vertical and lateral force. However, it undergoes continuous destructive reactions (wearing and damages) and abrasion of the cladding by the train wheels. It is obvious that wearing will result when two metal parts act against each other. However, occurrence of abnormal wearing such as rapid wearing of the rail side due to complex generation of various mechanisms at the contact surface between the rail and train wheel flange. It is not easy to simply examine the causes of occurrence of abnormal wearing of rail and train wheel flange. Although countless number of academicians and specialists are conducting researches on abnormal wearing of rail and vertical wearing of train wheels, I believe it is too early to argue on pros and cons due to insufficiency of officially verified information on the issue. This review will be focusing on the examples of repairs that reduced the generation of abnormal wearing of rail by reviewing and improving characteristics of wearing and slack, speed of the train and cant as well as status of lubricator by choosing the compound curves present in the section between the $Anguk{\sim}Jongno3-ga$ Stations of the Route No. 3 among the compound curve tracks of the Seoul Metro Routes No. 3 & 4 at which abnormal wearing is generated continuously.