• Journal of the korean academy of Pediatric Dentistry
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• v.42 no.1
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• pp.87-101
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• 2015

The premature loss of the mandibular primary canine is relatively frequent and a sign of the upcoming space problems in the transitional period. This situation is caused by the permanent lateral incisor resorbing the root of the primary canine during its eruption. Bilateral loss of primary canines in a crowded arch leads to the lingual tipping of the permanent incisors, with the consequent reduction in the arch perimeter and increase in overbite. When the loss of a primary canine is unilateral, tipping of the adjacent incisors occurs toward the space, resulting in midline deviation. In these situations, treatment possibilities, such as extraction of the antimeric tooth or placement of a passive lingual arch, can be applied; although there are some controversies concerning this. Most space problems with less than 4 mm can be resolved through preservation of the leeway space using sequential disking of the primary teeth and a passive lingual arch, regaining space or limited arch expansion in the late mixed dentition. In cases with 4~6 mm of space problems, arch expansion (A-P or transverse) can be applied. Space problems with more than 6 mm should be treated through diagnosis and treatment planning. Most of these cases will require extraction of permanent teeth including serial extraction (guidance of eruption).

• Journal of information and communication convergence engineering
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• v.12 no.3
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• pp.186-192
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• 2014

Monolithic three-dimensional integrated chips (3D ICs) are an emerging technology that offers an integration density that is some orders of magnitude higher than the conventional through-silicon-via (TSV)-based 3D ICs. This is due to a sequential integration process that enables extremely small monolithic inter-tier vias (MIVs). For a monolithic 3D memory, we first explore the static random-access memory (SRAM) design. Next, for digital logic, we explore several design styles. The first is transistor-level, which is a design style unique to monolithic 3D ICs that are enabled by the ultra-high-density of MIVs. We also explore gate-level and block-level design styles, which are available for TSV-based 3D ICs. For each of these design styles, we present techniques to obtain the graphic database system (GDS) layouts, and perform a signoff-quality performance and power analysis. We also discuss various challenges facing monolithic 3D ICs, such as achieving 50% footprint reduction over two-dimensional (2D) ICs, routing congestion, power delivery network design, and thermal issues. Finally, we present design techniques to overcome these challenges.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05b
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• pp.409-412
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• 2006

In process of reinforced concrete(RC) box structure, the heat of hydration may cause serious thermal cracking problems. In order to eliminate hydration heat of mass concrete, this paper reports results of hydration heat control in mass concrete using the OCHP(Oscillating Capillary tube Heat Pipe). Recently OCHP is drawn special attention from these points of low cost as well as short construction schedule for the manufacturing of heat exchanger, flexibility, simplification and high performance. There were three RC box molds$(1.2{\times}1.2{\times}1.2m)$ which shows a difference as compared with each other. One was not equipped with OCHP. While others were equipped with OCHP and these were cooled with air natural convection and spraying water respectively. The OCHP was composed of copper pipe with 12 turns(O.D : 4mm, I.D : 2.8mm). The working fluid was R-22 and its charging ratio was 30(Vol. %). In order to analyze the distribution of temperature and index figure of thermal crack in sequential placement of mass concrete, we used HYCON of computer program. As a result of the experiment, the peak temperature decreased about $15.6\sim23.4^{\circ}C$ than the general specimen and the probability of thermal crack generated in mass concrete decreased up to 0%.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.21 no.3
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• pp.257-265
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• 1999

To investigate the sequential changes in microvascular architecture and osseous regeneration during the bony healing after an application of the guided tissue regeneration method, we made artificial defects measuring $0.7cm{\times}0.3cm$ in size on femoral bones of rats measuring about 200gm and applied non-absorbable TEFE membrane at experimental sites but not at control sites. Then we observed the sequential changes and correlations between new vacuolation and bony regeneration using microvascular corrosion cast method and routine light microscopic observation at 1, 2 and 3 weeks after operation, respectively. The results showed that there were close relationships between regeneration of microvasculature and bone. In early phase, the invasion of granulation tissue at control sites delayed bony regeneration, however, in later phase, there was no remarkable differences in bony regeneration between control and experimental sites. The placement of barrier also affected in revascularization of regenerating bony defects. This is, the experimental sites showed parallel arranged nutritional vessels along long axis with well developed retiform plexus whereas the control revealed vertical invasion of microvasculature from outside of marrow space through bony defects which was also rearrange with time into parallel pattern with a vertical plexus but lesser organized than that of experimental sites. These findings suggest that the reconstruction of regenerating vasculature within the marrow cavity only may be sufficient and/or more be efficient in regeneration of bony defects.

• Journal of Information Technology Services
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• v.15 no.4
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• pp.73-83
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• 2016

Pedestrian safety was recently highlighted with a yellow carpet, a yellow-colored pavement material prepared for children waiting for signals for pedestrian crossing, without validation of its efficiency in practice. It was a promising device likely to assist highway safety by stimulating pedestrian to step on the yellow-colored area; it was generally called nudge effects. This paper delivers a study conducted to check the effectiveness of yellow carpet in three different aspects in vehicle driver's perspective by applying the newly introduced information technology (IT) service: Visual Attention Software (VAS). It was assumed that VAS developed by 3M in the United States should be able explain the Korean drivers' visual reaction behaviors since technology embedded in VAS was developed based on and proved by other various international countries and continents in the world. A set of pictures was taken at thirteen different field sites in seven school zone areas in the Seoul metropolitan area before and after the installation of a yellow carpet, respectively. Sets of those pictures were analyzed with VAS, and the results were compared based on the selective safety measures: the likely focusing on standing pedestrians (waiting for a pedestrian's green signal time) affected by its background (yellow-colored pavement) contrasting him or her. The test results from a set of before-and-after comparison analyses showed that the placement of yellow carpet would (1) increase 71% of driver's visual attention on pedestrian crossing areas and (2) change the sequential order of visual attention on that area 2.4 steps ahead. The findings would enhance deployment of such promising efficiency and thus increase children safety in pedestrian crossing. The result was promising to highlight the way to support the changes in conservative traffic safety engineering field by applying the advanced IT services, while much robust research was recommended to overcome the limitation of simplification of this study.

• Restorative Dentistry and Endodontics
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• v.42 no.1
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• pp.54-59
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• 2017

Objectives: The purpose of this study was to compare the antibacterial activity of urushiol against Enterococcus faecalis (E. faecalis) to that of NaOCl. Materials and Methods: The canals of thirty two single rooted human teeth were instrumented with Ni-Ti files (ProTaper Next X1, X2, X3, Dentsply). A pure culture of E. faecalis ATCC 19433 was prepared in sterile brain heart infusion (BHI) broth. The teeth were submerged in the suspension of E. faecalis and were incubated at $37^{\circ}C$ for 7 days to allow biofilm formation. The teeth were randomly divided into three experimental groups according to the irrigant used, and a negative control group where no irrigant was used (n = 8). Group 1 used physiologic normal saline, group 2 used 6% NaOCl, and group 3 used 10 wt% urushiol solution. After canal irrigation, each sample was collected by the sequential placement of 2 sterile paper points (ProTaper NEXT paper points, size X3, Dentsply). Ten-fold serial dilutions on each vials, and 100 µL were cultured on a BHI agar plate for 8 hours, and colony forming unit (CFU) analysis was done. The data were statistically analyzed using Kruskal-Wallis and Mann-whitney U tests. Results: Saline group exhibited no difference in the CFU counts with control group, while NaOCl and urushiol groups showed significantly less CFU counts than saline and control groups (p < 0.05). Conclusions: The result of this study suggests 10% urushiol and 6% NaOCl solution had powerful antibacterial activity against E. faecalis when they were used as root canal irrigants.

• Journal of English Language & Literature
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• v.56 no.5
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• pp.973-998
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• 2010

This paper aims at assessing the significance of Lyrical Ballads of 1798, the agreed inaugurator of English Romanticism, in terms of such key concepts as poetic "experiments," "conversation," and the authorial function. The 1798 volume marks an interesting incidence in which an author with no tangible substantiality can wield his authorial function over his works. The volume is signed without the named proper noun-its author is neither William Wordsworth nor Samuel Taylor Coleridge. The figure of the author in this case is realized by the poems he writes; he produces, and is produced by, his works-a fact that constitutes part of the poetic experiments manifested in the Advertisement. Working under this reciprocal production, the Author of the 1798 volume and his poems are collectively aiming at establishing a new class of poetry and an interpretive community. The notion of "conversation" is a key element in the thematic, stylistic ties among individual poems. Poems of the 1798 volume effect multi-layered, "blended" voices. Readers are expected to draw out the topological interweaving among poems through the practices of dialogic reading. In this light, the sequential necessity of "The Rime" and "Tintern Abbey" should be emphasized. They are stitched together in a logic of textual placement and the transition from one to the other is never arbitrary. Most of all, they are working under the same authorial function, complementing each other, and addressing the same poetic project in different textual locations. As an inaugural work of English Romanticism, Lyrical Ballads of 1798 in fact makes so many things happen and yet again anticipates something yet to come with elusiveness. The value of this poetic experiments should be judged not only by what is claimed in it, but what it sets out to do and "how far" it will be performed, as implied in the Advertisement. The efficacy of the volume, more than anything else, is dependent upon the performative power of words.

• Journal of Chest Surgery
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• v.24 no.9
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• pp.843-852
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• 1991

We prospectively studied postoperative cardiac arrhythmia after open heart surgery to analyze the types and incidence of cardiac arrhythmia and to predict preoperative risk factors. And also we evaluated the effectiveness of atrial and ventricular epicardial electrodes which were placed during operation Between March 1990 and August 1990, We had operated on in 211 patients and we studied 201 consecutive patients excluding 10 patients. The study group included 99 males and 102 female patients, ages 1 month to 75 years[Mean$\pm$SD=28.0$\pm$21.7 years]. Postoperatively, all patients were regularly seen by the cardiac surgeon and cardiologist, They had continuous electrocardiographic monitoring for the first 3 days, initially in the intensive care unit and were checked routine electrocardiography on the postoperative 7 days, The postoperative cardiac arrhythmia were analyzed and possible associations of this arrhythmia with various pre, intra, and postoperative factors were studied by univariate and multivariate discriminant analysis, The overall incidence of postoperative cardiac arrhythmia except relative sinus bradycardia was 36.8%;[74/201], The incidence of postoperative cardiac arrhythmia in acyanotic congenital heart disease: 19.4%, cyanotic congenital heart disease: 20.8%, cardiac arrhythmia surgery: 33.3%, acquired valvular heart disease: 60.9% and coronary artery occlusive disease: 38.9%. Both univariate and multivariate studies indicated the pre operative symptom duration[p = 0013], the duration of medication[p=0.003], presence of preoperative arrhythmia[p<0.001] and pre-operative left atrial dimension in echocardiography to be the factor promoting postoperative cardiac arrhythmia. Multivariate discriminant analysis showed that the presence of preoperative cardiac arrhythmia, bypass time and the duration of preoperative symptom duration conveyed considerable risk factor on post-operative arrhythmia. The atrial wire electrodes were used diagnostically in 36 and were used therapeutically in 89 among 201 patients. Atrial pacing were used to treat relative sinus bradycardia, accelerated junctional tachycardia or premature atrial or ventricular contractions in 51 patients. Atrioventricular sequential pacing were used in 16 patients and ventricular pacing were used in 20 patients. Hemodynamics were evaluated in 2 patients of relative sinus bradycardia before and after atrial pacing. The atrial pacing increased the amount of cardiac output to 15% more. Because of their great utility in the diagnosis and treatment of arrhythmias, we conclude that routine placement of atrial and ventricular electrodes at the time of operation is indicated regardless of the nature of the open-heart procedure.

• Journal of KIISE:Computer Systems and Theory
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• v.26 no.9
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• pp.1166-1176
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• 1999

연속 매체, 특히 비디오 데이타에 대한 일반 사용자 연산에는 재생뿐만 아니라 임의 속도 탐색 연산, 정지 연산, 그리고 그 외 다양한 연산이 있다. 이 연산 중에서 원하는 화면을 빨리 찾는 데에 유용한 고속 전진(FF: fast-forward)과 고속 후진(FB: fast-backward)은 재생 연산과는 달리 비순차적인 디스크 접근을 요구한다. 이러한 경우에 디스크 부하가 균등하지 않으면 일부 디스크에 접근이 편중되어 서비스 품질이 떨어진다. 본 논문에서는 디스크 배열을 이용한 저장 시스템에서 디스크 접근을 고르게 분산시키기 위하여 '소수 라운드 로빈(PRR: Prime Round Robin)' 방식으로 연속 매체를 디스크에 배치하는 기법에서 문제가 됐던 낭비된 디스크 저장 공간을 신뢰도 향상을 위해서 사용하는 '그룹화된 패리티를 갖는 소수 라운드 로빈(PRRgp: PRR with Grouped Parities)' 방식을 제안한다. 이 기법은 PRR 기법처럼 임의 속도 검색 연산에 있어서 디스크 배열을 구성하는 모든 디스크의 부하를 균등하게 할뿐만 아니라 낭비됐던 디스크 저장 공간에 신뢰도를 높이기 위한 패리티 정보를 저장함으로서 신뢰도를 향상시킬 수 있다. 신뢰도 모델링 방법으로 조합 모델과 마르코프 모델을 이용해서 결함발생율과 결함복구율을 고려한 신뢰도를 산출하고 비교.분석한다. PRR 기법으로 연속 매체를 저장하고 낭비되는 공간에 패리티 정보를 저장할 경우에 동시에 두 개 이상의 결함 발생 시에 그 결함으로부터 복구가 불가능하지만 PRRgp 기법에서는 약 30% 이상의경우에 대해서 동시에 두 개의 결함 발생 시에 저장한 패리티 정보를 이용한 복구가 가능할 뿐만 아니라 패리티 그룹의 수가 두 개 이상인 경우에는 두 개 이상의 결함에 대해서도 복구가 가능하다.Abstract End-user operations on continuous media (say video data) consist of arbitrary-rate search, pause, and others as well as normal-rate play. FF(fast-forward) / FB(fast-backward) among those operations are desirable to find out the scene of interest but they require non-sequential access of disks. When accesses are clustered to several disks without considering load balance, high quality services in playback may not be available. In this paper, we propose a new disk placement scheme, called PRRgp(Prime Round Robin with Grouped Parities), with enhanced reliability by using the wasted disk storage space in an old one(PRR: Prime Round Robin), in which continuous media are placed on a disk array based storage systems to distribute disk accesses uniformly. The PRRgp can not only achieve load balance of disks consisting of a disk array under arbitrary-rate search like PRR, but also improve reliability by storing parity information on the wasted disk space appropriately. We use combinatorial and Markov models to evaluate the reliability for a disk array and to analyze the results. When continuous media like PRR are placed and parity information on the wasted disk space is stored, we cannot tolerate more than two simultaneous faults. But they can be recovered by using stored parity information for about 30 percent as a whole in case of PRRgp presented in this paper. In addition, more than two faults can be tolerated in case there are more than two parity groups.