• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.35 no.6
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• pp.442-450
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• 2009

Purpose: Simultaneous implantation has been traditionally limited to patients with at least 5 mm of residual bone to ensure that the implant is completely stabilized. This is considered to be one of the most critical factors for primary implant stability and parallelism and, subsequently osseointegration. Recently, improved initial implant stability is provided by advancement of surgical techniques, implant designs and surface treatments. This has led surgeons to extending simultaneous treatment option to patients with below 4 mm of residual bone height, despite the lack of much data. The purpose of this study was to retrospectively evaluate and compare the status of implants which are installed by delayed and simultaneous methods. Material and methods: The subjects were patients(121 patients, 278 implants) who had been operated with sinus lifting from 2003 to 2007 in Sun Dental Hospital. Lateral window approach with autograft and xenograft(1:1 ratio) were carried out for all sinus lifting. 4 types of implant were used. The mean follow up period was 26.3 months(19 - 58 months) in delayed group, and 22.8 months(18 - 43 months) in simultaneous group. Results: The survival rate of implant restoration of this study was 98.2% in delayed group and 91.7% in simultaneous group. In simultaneous group, wide-platform type implants showed 100% survival rate. The total average of marginal bone loss in radiographs was $0.96\;{\pm}\;0.29\;mm$ in delayed group and $1.02\;{\pm}\;0.31\;mm$ in simultaneous group. Conclusion: Simultaneous implantation with sinus lifting(below 4mm of residual bone height) could be predictable treatment.

• Journal of Chest Surgery
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• v.39 no.8 s.265
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• pp.655-658
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• 2006

Mesothelial cyst is a rare mediastinal tumor and usually presents in the right cardiophrenic angle. However, it sometimes occurs in atypical locations and it’s locating in the posterior mediastinum, especially, is very rare. A large cystic mass of the posterior mediastinum between pericardium and vertebral body was incidentally recognized in a patient of a 30-year-old woman admitted due to traffic accident. Even though it was very large in size measuring 18 em at longest diameter and is extending mainly to the left pleural cavity, she had no symptomatic complaints. Complete excision was performed through video-assisted thoracoscopic surgery with a additional small working window, which was necessary for dissecting the deepest point to the right pleural cavity. She is in good condition without recurrence on long-term follow-up.

• Korean Institute of Interior Design Journal
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• v.23 no.5
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• pp.165-173
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• 2014

Located in Dornach, Switcherland Eurythmeum Anbau zu Haus Brodbeck (Rudolf Steiner-Halde, Eurythmeum Anbau zu Haus Brodbeck, 1923-1935) is one of the architectural works created by Rudolf Steiner (1861-1925) who has studied and established the cognitive and spiritual aspects of a human being, and is often cited as being the founder of anthroposophy. In fact, Eurythmeum Anbau zu Haus Brodbeck is not as well known as Steiner's other works, and it is perceived as less important than his major works of architecture including "Goetheanum", "Modellbau zu Malsch", and "Rudolf Steiner Haus Stuttgart". Nonetheless, this study is meaningful in itself since it is an important piece of architecture to gain an understanding of the characteristics of Steiner's late works, and the architectural characteristics of the Waldorf School where various active educational activities are taking place around the world. Eurythmeum Anbau zu Haus Brodbeck clearly exhibits the characteristics of the architectural space based on Steiner's anthroposophy as well as provides a window into promoting space efficiency by extending an existing building. Moreover, it provides a good learning opportunity to find out about how Steiner's architectural disposition has changed and developed with the use of new materials. With these points as a backdrop, the study aims to develop an understanding of the architectural characteristics of Eurythmeum Anbau zu Haus Brodbeck. Another important objective of this paper is to gain insight into the architectural implications in connection with the influence Eurythmeum Anbau zu Haus Brodbeck has had on Steiner's later works, by comparing his early works of architecture with those of his late works.

• Journal of the Korea Society for Simulation
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• v.22 no.1
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• pp.63-75
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• 2013

The School Bus Routing Problem(SBRP) seeks to plan an efficient schedule of a fleet of school buses that must pick up student from various bus stops and deliver them by satisfying various constraints; maximum capacity of the bus, maximum riding time of students, arrival time between a school's time window. By extending the existing SBRP, we consider a case study of SBRP with allowance of mixed-loading and dynamic arrivals reflecting the school bus operation of university in Korea. Our solution procedure is based on constructing the initial solution using sweep algorithm and then improving solution within the framework of the evolutionary approach known as efficient meta-heuristics. By comparing the various scenarios through the constraints relaxation for reflecting the real operational strategies, we assess the merit of our proposed procedure.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.4B
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• pp.288-297
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• 2003

The fast retransmit and fast recovery algorithm of TCP Reno, when multiple packets in the same window are lost, cannot recover them without RTO (Retransmission Timeout). TCP New-Reno can recover multiple lost packets by extending fast recovery using partial acknowledgement. If the retransmitted packet is lost again during fast recovery, however, RTO cannot be avoided. In this paper, we propose an algorithm called "Duplicate Acknowledgement Counting(DAC)" to alleviate this problem. DAC can detect the retransmitted packet loss by counting duplicate ACKs. Conditions that a lost packet can be recovered by loss recovery of TCP Reno, TCP New-Reno and TCP New-Reno using DAC are derived by modeling loss recovery behavior of each TCP. We calculate the loss recovery probability for random packet loss probability numerically, and show that DAC can improve loss recovery behavior of TCP New-Reno.

• Journal of KIISE:Computing Practices and Letters
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• v.8 no.3
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• pp.336-343
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• 2002

Nowadays, after appearance of wireless network the existent internet environment is changing into the united wire/wireless network. But the present TCP regards all of the packet losses on transmission as the packet tosses due to the congestion. When it is applied on the wireless path, it deteriorates the end-to-end TCP throughput because it regards the packet loss by handoff or bit error as the packet loss by the congestion and it reduces the congestion window. In this paper, for solving these problems we propose the method that controls the performance of TCP on the wireless link by extending ECN which is used as a congestion control mechanism on the existent wire link. This is the method that distinguished the packet loss due to the congestion from due to bit error or handoff on the wireless network, so it calls the congestion control mechanism only when there occurs the congestion in the united wire/wireless network.

• Korean Institute of Interior Design Journal
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• v.20 no.1
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• pp.154-164
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• 2011

The purpose of this study is to identify more types of residents in medium-sized apartments in Seoul by lifestyle that has been used as a variable of space planning and to investigate and present bathroom design appropriate for characteristics of each resident type. The article examines the general characteristics, lifestyle types, and preference for the bathroom design. A total of 642 samples, acquired via internet survey, were analyzed with the statistical computer program SPSS PC+ window version 16.0. The conclusion of the article are as follows: 1) The lifestyle of users living in medium-sized apartments are categorized into 4 types: trend seeking, aesthetic seeking, family seeking, information seeking types. 2) The preference for the bathroom design of trend seeking type, the toilet is a bidet-builtin type and the washstand is a semi-counter type and the bathtub is a spa type and the shower booth is a bathtub-extending type. The storage closet is a upper-fixed type with two sides, the finishing materials are tiles and PVC monorium, and light built in a wall. 3) The preference for the bathroom design of aesthetic seeking type, the toilet is a bidet-builtin type and the washstand is a semi-counter type and the bathtub is a whirlpool type and the shower booth is a steam-sauna type. The storage closet is a upper-fixed with one side and opened closet, the finishing materials are tiles. 4) The preference for the bathroom design of family seeking type, the toilet is a bidet-builtin type and the washstand is a stand type and the bathtub is a reclamation type and the shower booth is a partition type. The storage closet is a upper-fixed with three sides. 5) The preference for the bathroom design of information seeking type, the toilet is a bidet-builtin type and the washstand is a semi-counter and the bathtub is a spa type and the shower booth is a partition type. The storage closet is a upper-fixed type with two sides. The results of this study may be used as basic data in planning bathroom design for housing supply for housing suppliers, and used as significant information for residents to identify their own types that can be referred when they select apartments to live in.

• Journal of Broadcast Engineering
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• v.28 no.1
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• pp.79-89
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• 2023

A multi-view display is regarded as the most practical technology to provide a three-dimensional effect to a viewer because it can provide an appropriate viewpoint according to the observer's position. But, most multi-view displays with flat shapes have a disadvantage in that a viewer watches 3D images only within a limited front viewing angle. In this paper, we proposed a spherical display using a ball lens with spherical symmetry that provides perfect parallax by extending the viewing zone to 360 degrees. In the proposed system, each projection lens is designed to be packaged into a small modular array, and the module array is arranged in a spherical shape around a ball lens to provide vertical and horizontal parallax. Through the applied optical module, the image is formed in the center of the ball lens, and 3D contents are clearly imaged with the size of about 0.65 times the diameter of the ball lens when the viewer watches them within the viewing window. Therefore, the feasibility of a 360-degree full parallax display that overcomes the spherical aberration of a ball lens and provides a wide field of view is confirmed experimentally.

• Journal of KIISE:Databases
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• v.33 no.1
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• pp.42-55
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• 2006

We propose a single Index approach for subsequence matching that supports moving average transform of arbitrary order in time-series databases. Using the single index approach, we can reduce both storage space overhead and index maintenance overhead. Moving average transform is known to reduce the effect of noise and has been used in many areas such as econometrics since it is useful in finding overall trends. However, the previous research results have a problem of occurring index overhead both in storage space and in update maintenance since tile methods build several indexes to support arbitrary orders. In this paper, we first propose the concept of poly-order moving average transform, which uses a set of order values rather than one order value, by extending the original definition of moving average transform. That is, the poly-order transform makes a set of transformed windows from each original window since it transforms each window not for just one order value but for a set of order values. We then present theorems to formally prove the correctness of the poly-order transform based subsequence matching methods. Moreover, we propose two different subsequence matching methods supporting moving average transform of arbitrary order by applying the poly-order transform to the previous subsequence matching methods. Experimental results show that, for all the cases, the proposed methods improve performance significantly over the sequential scan. For real stock data, the proposed methods improve average performance by 22.4${\~}$33.8 times over the sequential scan. And, when comparing with the cases of building each index for all moving average orders, the proposed methods reduce the storage space required for indexes significantly by sacrificing only a little performance degradation(when we use 7 orders, the methods reduce the space by up to 1/7.0 while the performance degradation is only $9\%{\~}42\%$ on the average). In addition to the superiority in performance, index space, and index maintenance, the proposed methods have an advantage of being generalized to many sorts of other transforms including moving average transform. Therefore, we believe that our work can be widely and practically used in many sort of transform based subsequence matching methods.

• Composites Research
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• v.36 no.1
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• pp.1-15
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• 2023

Demand for energy consumption reduction is increasing according to the development expectations of future mobility. Lightweight structural materials are known as a method to reduce greenhouse gas emissions and improve energy efficiency. In particular, fiber reinforced polymer composite (FRP) is attracting attention as a material that can replace existing metal alloys due to its excellent mechanical properties and light weight. In this paper, industrial applications and research trends of carbon fiber reinforced composites (CFRP, carbon FRP) and self-reinforced composites (SRC) were reviewed based on the reinforcement, polymer matrix, and manufacturing process. In order to overcome the expensive process cost and long manufacturing time of the epoxy resin-based autoclave method, which is mainly used in the aircraft field, mass production of CFRP-applied electric vehicles has been reported using a high-pressure resin transfer molding process including fast-curing epoxy. In addition, thermoplastic resin-based CFRP and interface enhancement methods to solve the recycling issue of carbon fiber composites were reviewed in terms of materials and processes. To form a perfect matrix-reinforcement interface, which is known as the major factor inducing the excellent mechanical properties of FRP, studies on SRC impregnated with the same matrix in polymer fibers have been reported. The physical and mechanical properties of SRC based on various thermoplastic polymers were reviewed in terms of polymer orientation and composite structure. In addition, a copolymer matrix strategy for extending the processing window of highly drawn polypropylene fiber-based SRC was discussed. The application of CFRP and SRC as lightweight structural materials can provide potential options for improving the energy efficiency of future mobility.