• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.05a
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• pp.757-759
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• 2013

Until just a few years ago, digital circuit design techniques in register transfer level using Verilog or VHDL have been recognized as the up-to-date way compared with the traditional schematic design, and truly they have been used as the most popular skill for most chip designs. However, with the advent of era in which the complexity of semiconductor chip counts over billion transistors with advanced manufacturing technology, designing in register transfer level became too complex to meet the requirements of the needs, so the design paradigm has to change so that both design and synthesis can be done in higher level of abstraction. Bluespec SystemVerilog (BSV) is the only HDL which enables both circuit design and generating synthesizable code in the system level developed so far. In this contribution, I survey and analyze the features which supports the new paradigm in the BSV HDL, not very familiar to industry yet.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.78
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• pp.119-143
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• 2018

This research aims to review every important academic research on risk management in FTA and to suggest a future area for further research. This research area seems to focus on conceptual study or fact finding rather than on theory development or empirical research on causal relationship or theory testing. The National Assembly Digital Library analyzed the results of 3,576 researches on thesis and journals fromthe results of the FTA. Research on FTA is analyzed in four major themes. First, there have been previous studies on business performance such as FTA export performance and economic effect. Second, analyzed the effects of FTA in product and service. The products are classified into agricultural, marine products, manufacturing, textiles and clothing, medicinal pharmaceuticals, cosmetics, and others. Services are classified into educational and cultural contents, service industry and financial industry. Third, research on the risk management of FTA Origin is broadly classified into the use of country of origin and the verification of origin, and the use of origin includes the study of rules of origin and systems of origin and management. Origin verification was divided into origin verification and origin risk management. Fourth, study on the conclusion area of the FTA, studies were conducted on areas such as Korea-US FTA, Korea-China FTA, Korea-EU FTA, Korea-Japan FTA, Korea-Chile FTA, and Korea-ASEAN FTA. Search results through the FTA, focused on analyzing the FTA area and concept research by research purpose. In addition, research methods are mainly focused on documentary survey, and research areas are concentrated on specific countries such as China and USA. This implies a necessity for a future development in that research area. Other areas for future research may include case research on actual failures in FTA, proactive risk management strategy, and integrated risk management for export companies. Risk management in FTA may help investment expansion, and that is why research on the issue matters.

• Journal of Korea Spatial Information System Society
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• v.5 no.2 s.10
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• pp.23-31
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• 2003

As the results of the information project, manufacturing of the digital map and various thematic maps of the national land has been completed. Furthermore, it is necessary to organize a systemized management system, which can control and utilize all artificial features (e.g. buildings, roads, bridges etc.) as well as natural geographic features (e.g. rivers etc). Howener, it has difficulties in managing NGIS as a unified system, because of the discordance of DB of each geographic management organizations. Therefore, this study has been conducted to apply to the system and method providing geographic UFID that can be a key in order to managing, searching and utilizing geographic and artificial features and that makes it be able to estimate the location with the only identifier. Moreover, the system and method, providing geographic UFID, applies to systemized management of NGIS DB as well as consistency of information.

• The Journal of Advanced Prosthodontics
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• v.11 no.6
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• pp.331-340
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• 2019

PURPOSE. The purpose of this study is to assess the accuracy of three intraoral scanners along the complete dental arch and evaluate the feasibility of the assessment methodology for further in vivo analysis. MATERIALS AND METHODS. A specific measurement pattern was fabricated and measured using a coordinate measuring machine for the assessment of control distances and angles. Afterwards, the pattern was placed and fixed in replica of an upper jaw for their subsequent scans (10 times) using 3 intraoral scanners, namely iTero Element1, Trios 3, and True Definition. 4 reference distances and 5 angles were measured and compared with the controls. Trueness and precision were assessed for each IOS: trueness, as the deviation of the measures from the control ones, while precision, as the dispersion of measurements in each reference parameter. These measurements were carried out using software for analyzing 3-dimensional data. Data analysis software was used for statistical and measurements analysis (α=.05). RESULTS. Significant differences (P<.05) were found depending on the intraoral scanner used. Best trueness values were achieved with iTero Element1 (mean from 10 ± 7 ㎛ to 91 ± 63 ㎛) while the worst values were obtained with Trios3 (mean from 42 ± 23 ㎛ to 174 ± 77 ㎛). Trueness analysis in angle measurements, as well as precision analysis, did not show conclusive results. CONCLUSION. iTero Element1 was more accurate than the current versions of Trios3 and True Definition. Importantly, the proposed methodology is considered reliable for analyzing accuracy in any dental arch length and valid for assessing both trueness and precision in an in vivo study.

• Aerospace Engineering and Technology
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• v.3 no.1
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• pp.126-133
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• 2004

Photogrammetry, as its name implies, is a 3-dimensional coordinate measuring technique that uses photographs as the fundamental medium for metrology. In the last few years the accuracy of photogrammetry has increased dramatically thanks to the rapid advance of digital camera manufacturing technique. This paper discusses photogrammetric measurement of the interface surface of MSC(Multi-Spectral Camera), which is a main payload of KOMPSAT-2. Total 24 paper targets on the objective surfaces and two scale bars calibrated with high accuracy were used for measurement, and multiple images were taken from 11 different camera angles by using a spacecraft rotation dolly. As a result of analysis, 3D coordinates of each targeted point were obtained and the flatness value based on the selected reference plane was calculated and compared with the pre-determined requirement. The technique acquired by this study is expected to be used for the 3D precise measurement of ultra-light weight and inflatable space structures such as a satellite antenna and a solar array.

• Restorative Dentistry and Endodontics
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• v.43 no.3
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• pp.27.1-27.9
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• 2018

Objectives: The aim of this in vitro study was to evaluate the effects of the thickness and shade of 3 types of computer-aided design/computer-aided manufacturing (CAD/CAM) materials. Materials and Methods: A total of 120 specimens of 2 shades (A1 and A3) and 2 thicknesses (1 and 2 mm) were fabricated using VITA Mark II (VM; VITA Zahnfabrik), IPS e.max CAD (IE; IvoclarVivadent), and VITA Suprinity (VS; VITA Zahnfabrik) (n = 10 per subgroup). The amount of light transmission through the ceramic specimens was measured by a radiometer (Optilux, Kerr). Light-cured resin cement samples (Choice 2, Bisco) were fabricated in a Teflon mold and activated through the various ceramics with different shades and thicknesses using an LED unit (Bluephase, IvoclarVivadent). In the control group, the resin cement sample was directly light-cured without any ceramic. Vickers microhardness indentations were made on the resin surfaces (KoopaPazhoohesh) after 24 hours of dark storage in a $37^{\circ}C$ incubator. Data were analyzed using analysis of variance followed by the Tukey post hoc test (${\alpha}=0.05$). Results: Ceramic thickness and shade had significant effects on light transmission and the microhardness of all specimens (p < 0.05). The mean values of light transmittance and microhardness of the resin cement in the VM group were significantly higher than those observed in the IE and VS groups. The lowest microhardness was observed in the VS group, due to the lowest level of light transmission (p < 0.05). Conclusion: Greater thickness and darker shades of the 3 types of CAD/CAM ceramics significantly decreased the microhardness of the underlying resin cement.

• 전자공학회논문지 IE
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• v.48 no.2
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• pp.6-11
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• 2011

This paper describes the design of new method of propagation delay measurement in micro and nanostructures during characterization of ASIC standard library cell. Providing more accuracy timing information about library cell (NOR, AND, XOR, etc.) to the design team we can improve a quality of timing analysis inside of ASIC design flow process. Also, this information could be very useful for semiconductor foundry team to make correction in technology process. By comparison of the propagation delay in the CMOS element and result of analog SPICE simulation, we can make assumptions about accuracy and quality of the transistor's parameters. Physical implementation of phase error accumulation method(PHEAM) can be easy integrated at the same chip as close as possible to the device under test(DUT). It was implemented as digital IP core for semiconductor manufacturing process($0.11{\mu}m$, GL130SB). Specialized method helps to observe the propagation time delay in one element of the standard-cell library with up-to picoseconds accuracy and less. Thus, the special useful solutions for VLSI schematic-to-parameters extraction (STPE), basic cell layout verification, design simulation and verification are announced.

• Journal of the Korea Convergence Society
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• v.8 no.7
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• pp.199-205
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• 2017

Despite the economic downturn, the amount of clothing being discarded is increasing due to the fast fashion. The purpose of this study is to propose a fashion sharing service development to settle the rational consumption culture along with the abandoned clothes problem. Shared fashion rental service has attracted as a solution to environmental problems not only when clothes are incinerated but also in manufacturing process, but there is a lack of precedent research. Therefore, this study is meaningful in that it has developed two development plans based on the results of analysis of service case based on three factors by Rachel Botsman. First, active community development. Second, it is the creation of goods through activation of the shared economy. In this study, there are limitations that can't be proved through actual application, so more research is needed through empirical studies on actual users in the future.

• Journal of Technologic Dentistry
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• v.39 no.1
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• pp.17-24
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• 2017

Purpose: The purpose of this study was to evaluate the internal fitness of the resin coping that was fabricated by the traditional and Digital manufacturing methods through 3-dimensional analysis. Methods: maxillary right second molar was chosen implant master model. Custom-built impression trays were manufactured. After screwing the pick-up impression coping onto the master cast, impressions were made with silicone impression. The Working model was then made with type IV stone. The coping was fabricated: SLAC group (n=8), APPC group (n=8), LAPC group (n=8) Resin coping data was measured by using a three-dimensional evaluation program. Internal fitness was calculated by RMS (Root Mean Square).It measures mean and Standard Deviation (SD). Results: Three groups are measured $47.11{\pm}(3.08){\mu}m$ total RMS of SLAC group, $48.35({\pm}1.55{\mu}m)$ for total RMS of LAPC group, $43.45{\pm}2.09{\mu}m$ for total RMS of APPC group. Measured value is gradually increased. Followed by autopolymerized pattern resin; Stereolithography resin, Light-activated pattern resin But there were no differences stastically(P>0.321). Conclusion: Evaluation of internal fitness on Resin copings was fabricated by three-ways methods showed that no differences statistically significant and clinically acceptable results.

• Journal of Computational Design and Engineering
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• v.1 no.1
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• pp.27-36
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• 2014

Similar to the essential components of many mechanical systems, the geometrical properties of the teeth of spiral bevel gears greatly influence the kinematic and dynamic behaviors of mechanical systems. Logarithmic spiral bevel gears show a unique advantage in transmission due to their constant spiral angle property. However, a mathematical model suitable for accurate digital modeling, differential geometrical characteristics, and related contact analysis methods for tooth surfaces have not been deeply investigated, since such gears are not convenient in traditional cutting manufacturing in the gear industry. Accurate mathematical modeling of the tooth surface geometry for logarithmic spiral bevel gears is developed in this study, based on the basic gearing kinematics and spherical involute geometry along with the tangent planes geometry; actually, the tooth surface is a parametric surface defined on a parallelogrammic domain. Equivalence proof of the tooth surface geometry is then given in order to greatly simplify the mathematical model. As major factors affecting the lubrication, surface fatigue, contact stress, wear, and manufacturability of gear teeth, the differential geometrical characteristics of the tooth surface are summarized using classical fundamental forms. By using the geometrical properties mentioned, manufacturability (and its limitation in logarithmic spiral bevel gears) is analyzed using precision forging and multiaxis freeform milling, rather than classical cradle-type machine tool based milling or hobbing. Geometry and manufacturability analysis results show that logarithmic spiral gears have many application advantages, but many urgent issues such as contact tooth analysis for precision plastic forming and multiaxis freeform milling also need to be solved in a further study.