• 대한치과의사협회지
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• 제50권8호
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• pp.482-506
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• 2012

Dentists have been striving to find ways to relieve patients' pain and discomfort. The prestige of dentists is made up of dentists' self-sacrifice, academic research and pursuit of patients' well being. However, nowadays the dentists' prestige has been lost and practice on humanity has merely existed. At this time, it is meaningful to shed new light on life of a pioneer in Korean dentistry and take some time for self-examination. Today, we are going to look into life of Dr. Jong-Suh Ahn and his achievements in Korean dentistry. In 1925, Dr. Ahn Jong Suh graduated from KyungSung Dental school as a first graduating class. Then, he learned advanced dentistry at Severance Hospital and in April of 1932 as a young dentist with full of potentials, he opened his dental clinic in Tianjin, China. As an awakening Korean, in 1925 he organized an association of Korean dentists, called HanSung Dental Association and worked as a secretary to manage general affairs. Han Sung Dental Association later became today's Korean Dental Association. On December 9th, 1945, he founded ChoSun Dental Association. He accomplished great deals during his five consecutive terms as a chairman and held other important positions with prestige to lead and expand the scope Korean dental association. There were three other successors to Dr. Ahn as the presidents of Dental Association. Dr. Yong-Jin Kim had a great interest in internal affairs and dental materials. Dr. Myung-Jin Park was active in scientific affairs and Dr. Dong-Chan Han focused on smooth operation of the association. From 1945 to 1963, Dr. Ahn submitted important agendas such as dentist's qualification, scientific and academic affairs, general affairs, dental materials, public oral health, and dental administration to Dental Association's general meeting and central committee. Dr. Ahn overcame hardships of Japanese imperialism, celebrated independence of Korea, experienced 6.25 Korean War and lived through evolving Korean dentistry in 1960s. Dr. Jong-Suh Ahn, who showed the prestige of dentist and expanded the scope of dental association, is exemplary to all dentists.

• 대한소아치과학회지
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• 제26권2호
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• pp.232-239
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• 1999

유치의 탈락과 영구치의 맹출은 정상적이고 예측 가능한 생리적인 과정이다. 치아 발육의 정확한 예측은 어린이의 치료 계획의 수립에 있어서 중요하다. 어린이의 연령과 그에 해당하는 치아 발육의 정상치가 여러 연구자들에 의해 조사되었다. 그러나 다양한 요소에 의해 치아의 정상 발육이 영향받을 수 있고 치아의 맹출을 촉진하거나 지연시킬 수 있다. 특히 농양이 있던 유치의 조기 발거나 탈락은 영구 계승치의 맹출에 뚜렷한 영향을 미칠 수 있다. 유치의 농양은 영구치를 덮은 골을 흡수시키고 따라서 발육상태에 관계 없이 영구치는 맹출할 수 있다. 유구치가 일찍 탈락 또는 발거되고 영구 계승치의 맹출이 조기에 일어나면 치아의 편향과 회전, 맹출 순서의 변경, 이웃 치아의 매복, 중심선 변위 등의 다양한 중요한 사건이 발생할 수 있다. 이에 저자는 서울대학교 병원 소아치과에 내원한 환아들의 조기 맹출한 영구 계승치의 임상적, 방사선학적 특징과 그로 인한 영향을 알아보고, 그에 따른 적합한 처치와 추후 관찰 사항을 보고하고자 한다.

• 한국항공우주학회지
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• 제38권9호
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• pp.914-924
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• 2010

본 논문에서는 지난 2009년 9월 30일 3년간의 정상임무 운영을 성공적으로 종료하고 연장임무 운용 중인 아리랑위성 2호의 실제 궤도데이터를 이용한 초기운용 및 임무기간 중 궤도분석 결과를 기술하였다. 초기 궤도운용을 위한 준비 및 수행결과들에 대해 중점을 두었으며, 동일 임무궤도 상에서 운용되었던 아리랑위성 1호와의 정상임무 기간 동안 서로 다른 우주환경(특히 태양활동)이 궤도변화에 미치는 영향력을 비교, 분석하였다. 본 논문에서 정리된 내용들은 추후 저궤도상에서 운용될 아리랑위성 시리즈(3호, 5호 3A호 등)들의 초기 및 정상 임무기간 동안 궤도운용 시 안정성과 효율성을 높이는데 주요 참고자료가 될 것으로 사료된다.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회/대한산업공학회 2005년도 춘계공동학술대회 발표논문
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• pp.1101-1107
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• 2005

Mold industry has the difficulty to employ young people as the successors of the skilled workers, because it has been regarded as a 3D-jobs(dirty, difficult, and dangerous). To overcome this situation, thus, manufacturing technologies maintained in the factory should be systemized, and engineering systems should support unskilled workers to do their jobs without any difficulty. As a research of developing the supporting system, this study proposes a decision support system that facilitates unskilled workers to easily select high quality NC-data, as well as to increase productivity. The proposed system is assumed to follow a CAM operation scenario that consists of next three steps: 1) identifying several process plans and enumerating feasible unit machining operations (UMOs) from material and part surface information, 2) creating all feasible NC-data based on UMOs using a commercial CAM system, 3) selecting the best NC data among the feasible NC data using four screening criteria, such as machining accuracy, machining allowance, cutting load, and processing time. A case study on the machining of a camera core mold is provided to demonstrate the proposed system.

• 한국정보과학회논문지:시스템및이론
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• 제34권5_6호
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• pp.238-248
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• 2007

최근 PDA의 대중화, 텔레메틱스 산업의 발전에 따라 제한된 저장장치를 갖는 모바일 임베디드 시스템에서 PC와 같은 다양한 소프트웨어를 사용하고자하는 수요가 늘어나고 있다. 그에 따라 소프트웨어 스트리밍 서비스의 필요성이 증가하고 있으나 소프트웨어를 속도가 느린 무선 네트워크를 통해 블록단위로 전송받아 실행속도가 느린 문제점이 있다. 그리하여 이를 보완해주는 선인출 알고리즘이 필요하다. 본 논문에서는 기존에 연구된 선인출 알고리즘인 최근 접근 블록 알고리즘(LS)과 PPM 기반 알고리즘을 소프트웨어 스트리밍 서비스에 적용시켜 성능을 측정하고 분석한 결과를 토대로 고안된 확률 기반 다중 접근 블록(PMS) 알고리즘을 제안한다. LS의 적중률은 60%정도로 낮지만 메모리 사용량이 적다. 그에 반해 PPM 기반 알고리즘은 메모리 사용량은 많지만 96%이상의 높은 적중률을 보인다. PMS는 블록 단위의 소프트웨어 스트리밍 서비스의 특징과 PPM 기반 알고리즘의 특성을 이용하여 LS의 단점을 보완해 N개의 접근 블록을 확률을 기반으로 저장하고 선인출에 이용한다. 이러한 PMS는 보다 적은 공간오버헤드를 가지면서 PPM 기반 알고리즘과 비슷한 적중률을 나타내 높은 메모리 효율을 나타낸다.

• Journal of Korean Dental Science
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• 제7권1호
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• pp.31-37
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• 2014

Dentigerous cyst (DC) is an odontogenic cyst associated with the crown of an impacted, embedded, unerupted, or developing tooth. It is the second most common type of odontogenic cysts, accounting for 14% to 24% of all jaw cysts. Although these cysts occur more frequently during the second and third decades of life, they can also be found in children and adolescents in the mixed dentition stage. Treatment of the odontogenic cyst involves enucleation or marsupialization/decompression methods. The latter approach is preferred for larger cysts, and it is especially helpful in adolescent patients in conserving the unerupted permanent successors. The aim of treatment for DC is the complete elimination of pathology and maintenance of dentition with minimal surgical intervention. Recently defined criteria for the selection of treatment modality include the cyst size and location of the cyst, patient age, dentition involved, stage of root development, position of the tooth involved in the jaw, and relationship with the surrounding vital structure. Marsupialization or decompression technique has been advocated by several authors for treating DCs among young patients. In this conservative technique, the creation of an accessory cavity helps relieve intra-cystic pressure and accelerate the healing of cystic lesion. This technique has been successfully performed and is indicated for growing children and adolescents. Here, we report a large cyst lesion in the mandible treated by marsupialization for conservative management. In conclusion, successful reduction in size was achieved, and intraoperative complication could be prevented.

• 한국의류산업학회지
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• 제18권4호
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• pp.412-423
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• 2016

This paper explores the possibility, and suggests an experimental procedure, of industrial application of traditional textile design techniques, such as hand silkprinting and natural dyeing. Theoretical and traditional background of this study is William Morris and his followers' Arts and Crafts Movement from the late 19th century to the early 20th century, which laid the philosophical as well as technical foundations of modern textile design tradition. Based on the basic understanding of the design philosophy, and starting from the design techniques of Morris and his successors, I made some experimental and systematic color plans reflecting and exploiting the physical traits and structure of jacquard woven silk material fabrics. And I applied hand silkscreen printing techniques on the jacquard silk fabrics of my own making, while testing various color combinations of natural dyes. After finishing final processing of design samples, I could get textile design products which met the criteria of my original expectation, i.e., eco-friendly and aesthetic design samples that can also be produced in automatized mass production system of contemporary textile industry. The conclusion of this experimental study is that I can expect the natural dyeing techniques, jacquard silk fabrics design techniques, silkprinting techniques, and the basic processes used in this study to be safely applied for contemporary commercial textile industry utilizing automatized silkscreen printing system and digital printing devices.

• 한국환경복원기술학회지
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• 제16권3호
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• pp.83-95
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• 2013

To understand natural regeneration and stand development after fire in mixed broadleaved-coniferous forests of Sikhote-Alin Mountains, ten sample plots of $50m{\times}50m$ size were established in 1975 and 1983 at the stands burned by wildfires in 1973 and 1982, respectively. And, the number of naturally regenerated seedlings were monitored in two $50m{\times}4m$ subplots in each plot. The most fire-sensitive conifer species is Abies nephrolepis, while Betula costata is the most fire-sensitive broadleaved tree species. The most fire-resistant species were Q. mongolica, T. taquetii and A. mono. The results of 20 and 30 years after the fire showed that pioneer tree species, e.g. Populus, Salix, and Betula, were regenerated immediately at the early stage of stand development and grew where there is a mono canopy layer with high density. On the other hand, the densities of successors, e.g. Pinus koraiensis, Picea jezoensis, Abies nephrolepis, Acer mono and Tilia taquetii, which were present in the study plots before the fire, increased gradually. Naturally regenerated tree species after forest fire by the growth rate were divided into three groups according to their annual height growth. The seral tree species (Betula costata, Betula platyphylla, Padus maackii, Populus tremula and Sarix caprea) belong to the first group and have the highest growth rate (from 40 to 96 cm per year). The late successional broad-leaved trees (Tilia taquetii, Acer mono and Quercus mongolica) belong to the second group and have intermediate annual height growth (from 3.7 to 13.5 cm per year). The late successional coniferous species (Picea jezoensis, Pinus koraiensis and Abies nephrolepis) form the third group and have the least annual height growth (from 1.4 to 3.5 cm per year).

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권8호
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• pp.2894-2909
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• 2015

As the number of mobile devices such as smart phones and tablets explodes, the need for new services or applications is also rapidly increasing. Smart class application is one of the emerging applications, in which most of contents are distributed to all members of a class simultaneously. It is highly required to select relay nodes to cover shadow area of radio as well as extend coverage, but existing algorithms in a smart class environment suffer from high control packet overhead and delay for exchanging topology information among all pairs of nodes to select relay nodes. In addition, the relay selection procedure should be repeated in order to adapt to the dynamic topology changes caused by link status changes or device's movement. This paper proposes the learning based relay selection algorithm to overcome aforementioned problems. The key idea is that every node keeps track of its relay quality in a fully distributed manner, where RQI (Relay Quality Indicator) is newly defined to measure both the ability of receiving packets from content source and the ability of successfully relaying them to successors. The RQI of each node is updated whenever it receives or relays broadcast packet, and the node having the higher RQI is selected as a relay node in a distributed and run-time manner. Thus, the proposed algorithm not only removes the overhead for obtaining prior knowledge to select relay nodes, but also provides the adaptability to the dynamic topology changes. The network simulation and experimental results prove that the proposed algorithm provides efficient and reliable content distribution to all members in a smart class as well adaptability against network dynamics.

• 대한치과교정학회지
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• 제15권2호
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• pp.341-352
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• 1985

The primary objective of this study is to estimate of the mesiodistal crown diameters of the unerupted permanent successors derived from the mesiodistal crown diameters of the deciduous teeth in Korean population. The subjects were 54 individuals (twenty nine boys and twenty five girls) with normal occlusion aged 6 to 13 years. The mesiodistal crown diameters of the deciduous and the successional permanent teeth were measured from the longitudinal dental cast models using the sliding calipers (Mitutoyo Co.). From the study, the results are as follows; 1. Sex differences of mesiodistal won diameters were less in the deciduous teeth, but male were more than that of female in the successional permanent teeth. 2. The mesiodistal crown diameters of the deciduous central incisors, lateral incisors, canines were smaller than that of the successional permanent teeth and the deciduous 1st molars, and 2nd molars were more larger than that of the successional permanent teeth. 3. Size differences between sum of the mesiodistal crown diameters of central incisors and lateral incisors in the decidous teeth and the successional permanent teeth were $7.20{\pm}1.79mm$ in upper, $5.38{\pm}1.64mm$ in lower and that of canine,1st molar and 2nd molar in the deciduous teeth and the successional permanent teeth were $0.56{\pm}1.19mm$ in upper, $2.22{\pm}1.19mm$ in lower. 4. In male, the correlation coefficients between the upper deciduous central incisor and the successional permanent tooth (r = 0.57) and in female, the correlation coefficients between the upper deciduous 1st molar and the successional permanent tooth (r=0.67) appeared the highest. 5. The regression constants were determined to estimate the mesiodistal crown diameters of the unerupted successional permanent teeth.