• Imaging Science in Dentistry
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• v.36 no.2
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• pp.95-101
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• 2006

Purpose : Bony strength is dependent on bone mass and bony structure. So this study was designed to investigate the relationship between the bone mass and bony trabecular characteristics. Subjects and Methods : Study subjects were 51 females (average age 68.6 years) and 20 males (average age 66.4 years). Bone mineral density (BMD, $grams/cm^2$) of proximal femur was measured by a dual energy X-ray absorptiometry (DEXA). Regions of interest (ROIs) were selected from the digitized radiographs of proximal femur. A customized computer program processed morphologic operations (MO) of ROIs. 44 skeletal variables of MO were calculated from ROIs on the Ward's triangle and greater trochanter of femur. WHO BMD classes were predicted by MO variables of the same ROI. Classification and Regression Tree analysis was used for calculating weighted kappa values, sensitivity and specificity of MO. Results : The discriminating factors of morphologic operation were branch point, branch point [per cm sq]. Age also played important role in distinguishing osteoporotic classes. The sensitivity of MO at Ward's triangle and Greater Trochanter was 91.8%, 65.6%, respectively. The specificity of MO was 100% at Ward's triangle and Greater Trochanter. Conclusion : Bony trabecular characteristics obtained using radiological bone morphometric analysis seem to be related to bone mass.

• Journal of the Korean Ceramic Society
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• v.51 no.4
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• pp.231-242
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• 2014

An interconnect in solid oxide fuel cells (SOFCs) electrically connects unit cells and separates fuel from oxidant in the adjoining cells. The interconnects can be divided broadly into two categories - ceramic and metallic interconnects. A thin and gastight ceramic layer is deposited onto a porous support, and metallic interconnects are coated with conductive ceramics to improve their surface stability. This paper provides a short review on ceramic materials for SOFC interconnects. After a brief discussion of the key requirements for interconnects, the article describes basic aspects of chromites and titanates with a perovskite structure for ceramic interconnects, followed by the introduction of dual-layer interconnects. Then, the paper presents protective coatings based on spinel-or perovskite-type oxides on metallic interconnects, which are capable of mitigating oxide scale growth and inhibiting Cr evaporation.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.4
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• pp.393-400
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• 2003

This paper deals with the design and manufacturing technique of EQM(Engineering Qualification Model) of input multiplexer(IMUX) for the Ku-band satellite transponder. Channel dropping method by circulator chain structure is adopted for demultiplexing each channel. External equalizers are attached behind channel filters fur reduction of group delay variation and amplitude variation simultaneously. Both channel filters and equalizers adopted dual-mode technique in design f3r mass and volume reduction. Channel filters are designed to have 8-pole elliptic response and equalizers to be of 2-pole reflection type. For good temperature stability characteristics, INVAR36 material is used for channel filters and external equalizers. Vibration test, Thermal Vacuum Test, and EMC test have been performed on input multiplexer and it is shown to be suitable for Ku-band satellite transponder.

• Journal of the Korea Society of Computer and Information
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• v.13 no.1
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• pp.273-281
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• 2008

In a knowledge-information based society, effective management across IT industries, value of information and interoperation are more important than eyer before. Therefore, ITA/EA which helps to plan and manage IT systematically and effectively, was enacted and announced in 2005 and has been considered as an innovative IT management approach. Unfortunately, however, new standardization of ITA/EA has not fully discussed yet. How to successfully apply EA/ITA to IT is considered as the most urgent challenge and this study aims to find out the most effective method. To this end, it was emphasized that training systems for specialized experts must be operated systematically through 'standardization of terms and tasks' and 'standardization of manpower training' and certification of specialty must be newly established. In addition. it was strongly demanded that dual structure caused by mixed concepts between ITA and EA must be eliminated. At the same time. a new model for domestic standardization was suggested so that not only ITA/EA can be recognized as IT engineering but also professional engineers can accept ITA/EA as a scientific field. In summary, this study is intended to propose how to improve information management efficiency through ITA/EA.

• Journal of Korea Society of Industrial Information Systems
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• v.21 no.1
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• pp.43-50
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• 2016

In this paper, new automatic LC calibrator is proposed for realizing a passive LC filter with almost constant frequency characteristic regardless of the PVT variations. The SAW-less GPS RX front-end is implemented using a 65nm CMOS process using the proposed LC calibrator. Also, new dual-mode low noise amplifier (LNA) structure is proposed to generate the RF signal required for the LC calibrator. The characteristics of the implemented GPS RX front-end show the voltage gain of about 42.5 dB, noise figure of below 1.35 dB, the blocker input P1dB of -24 dBm in case of the worst blocker signal at 1710 MHz frequency, while it consumes 7 mA current at 1.2 V power supply voltage.

• Journal of the Korean Home Economics Association
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• v.24 no.4
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• pp.147-162
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• 1986

This research has dual purposes. First, it was designed to determine the level of children's spatial environment in the residences, thereby, to make a vision for children's furniture as an industrial design product. Second, it was intened to find out the children's perceptual pattern toward the furniture, thereby to give some implications for future design development. For the second purpose, descriptors were screened with construct validity and their factor structure was identified. The subjects were 1,197 children from 1st grade of elemantary school through 3rd grade of middle school, and their 1,197 parents for the first purpose, and 560 children from 6th grades of elemantary school and 3rd grade of middle school for the second purpose. The first parts of findings were 1) present interests of parents of household above middle income level in Seoul in making their children's spatial environment desirable is quite high. 2) Space segregation stage in terms of physical and conceptual aspects showed very fast development, that is, there will have been very good changes for children's room to be a very well furnished and independent space for them. 3) Children's opinions were quite well reflected when purchasing the present furniture, and this tendency seemed to be more likely happend in future. These findings mentioned above gave and confirmed the visions for future children's furnished environment. The second parts of findings were such that the perceptual pattern for furniture by children showed aesthetic design appearance, functionality and durability, and the characteristic of line. This result impliated especially that designers should be every careful to manipulate or use the line of the furniture products. The 22 representative descriptors selected can be used as an evaluation instrument for furniture products.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.6
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• pp.1166-1174
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• 2004

In this paper, a design of RISC-based transmission wrapper processor for TCP/IP protocol stack is described. The processor consists of input and output buffer memory with dual bank structure, 32-bit RISC microprocessor core, DMA unit with on-the-fly checksum capability, and memory module. To handle the various modes of TCP/IP protocol, hardware-software codesign approach based on RISC processor is used rather than the conventional state machine design. To eliminate large delay time due to sequential executions of data transfer and checksum operation, DMA module which can execute the checksum operation along with data transfer operation is adopted. The designed processor exclusive of variable-size input/output buffer consists of about 23,700 gates and its maximum operating frequency is about 167MHz under 0.35${\mu}m$ CMOS technology.

• Journal of IKEEE
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• v.21 no.3
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• pp.219-226
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• 2017

This paper was studied the double-band monopole antenna design with Mu-negative metamaterial unit cell, which operates at 700MHz and 2.45GHz band. Mu-negative unit cell made of the interdigital capacitor structure to operate a double-band antenna by inserting it into an antenna radiator unit. In addition, the parasitic conductor is implemented on the back side of the antenna radiation part, so that the resonance point of the antenna can be controlled and the bandwidth is improved. Finally, we implemented an antenna operating in the 750MHz UHD band and the 2.45GHz WiFi band. The designed antenna has a size of $200{\times}100mm^2$. Experimental results show that the 8dB bandwidth and gain characteristics at 750MHz band are 320MHz(42.7%), 5.28dB, 6dB bandwidth and gain at 2.45GH are 540MHz (21.6%), -0.46dB. From the experimental results, we confirmed that the resonance point with theoretical value is in agreement with experimental value, and the radiation patterns are have the omnidirectional characteristic in both bands.

• Bulletin of the Korean Chemical Society
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• v.34 no.2
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• pp.447-452
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• 2013

In this study we report a new method for the synthesis of a silica monolithic column bed with bimodal pores (throughpores and mesopores). The template induced synthesis method was used to direct bimodal pores simultaneously instead of the usual post base-treating method. Block polymer Pluronic F127 was chosen as a dual-function template to form hierarchically porous silica monolith with both macropores and mesopores. This is a simplification of the method of monolithic column preparation. Poly(ethylene glycol) was used as a partial substitute for F127 can effectively prevent shrinkage during the monolith aging process without losing much surface area (944 $m^2/g$ to 807 $m^2/g$). More importantly, the resultant material showed a much narrower mesopore size (centered at 6 nm) distribution than that made using only F127 as the template reagent, which helps the mass transfer process. The solvent washing method was used to remove the remaining organic template, and it was proved to be effective enough. The new synthesis method makes the fabrication of the silica monolithic column (especially capillary column) much easier. All the structure parameters indicate that monolith PFA05 prepared by the above method is a good material for separation, with the merits of much higher surface area than usual commercial HPLC silica particles, suitable mesopore volume, narrow mesopore size distribution, low shrinkage and it is easily prepared.

• Culinary science and hospitality research
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• v.17 no.5
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• pp.139-153
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• 2011

The study is a hotel firm's brand evidence on the switching and relational performance by identifying a causal relationship to the differentiated and competitive was to provide useful information. Units of samples for evidence of brand switching hotels in Seoul participated in surveys customers in 2011, from June 10 to 20 July 2011 for a total of 500 copies for distribution and the Department of dual 408 with SPSS 18.0 and AMOS 18.0 Using factor analysis and reliability verification carried out, and presented research in order to test the hypothesis covariance structure analysis was performed. Analysis, employee services switching barriers and switching costs showed no significant affect. Switching barriers and switching costs, brand name, image congruence transition castle wall and switching costs, alternative attractiveness showed no significant visible results. And perceived price on switching barriers to conversion rates showed was significant affect. Second, switching barriers, switching costs, alternative attractiveness and that the relationship, to help conversion of non-financial performance showed no significant affect. Third, the practitioner services, brand names, images, match the castle there, and non-financial performance of the transition showing a statistically significant result was found.