• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2007년도 춘계학술대회 논문집
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• pp.160-164
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• 2007

In the steel industry, there is a need to produce large forged parts for the automobile industries, the flight and shipping industries ad military industries. In the steel-industry application, a cogging technique for cast ingots is required, because the major parts are needed as one large body in order to obtain higher quality. Therefore, cogging process is the primary step in manufacturing of practically large open-die forging. In the cogging process, internal voids have to be eliminated as defects, The present work is concerned with the elimination of the internal voids in large ingots so as obtain sound products. In this study, hot compression tests were carried out to obtain the flow stress of cast microstructure at different temperature and strain rates. The FEM analysis are performed to investigate the overlap defect of cast ingots during cogging stage. The measure flow stress data were used to simulate the cogging process of cast ingot using the practical material properties. Also the analysis of void closure are performed by using the $DEFORM^{TM}$-3D. The calculated results of void closure behavior are compared with the measured results before and after cogging, which are scanned by the X-ray scanner. From this result, the criteria for deformation amounts effect on the void closure can be investigated by the comparison of practical experiment and numerical analysis.

• 치과방사선
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• 제17권1호
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• pp.151-162
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• 1987

The author obtained the computed tomograms around the condylar head from 10 normal subjects and 5 patients having clicking condylar head from 10 normal subjects and 5 patients having clicking sound or limitation of mouth opening by using a Hitachi-W 500. And then. the author had the axial analysis of condyle position and sagittal analysis of that after sagittal reformation on centric occlusion and 18㎜ interincisal opening. Transcranial view and submentovertex view were taken and compared with computed tomographic view. The obtained results were as follows: 1. Median angle of long axis of condylar head was 17 degrees on centric occlusion and the angles of long axis of both condylar heads were reduced symmetrically on 18㎜ interincisal opening in normal group. however. in the patient group, the affected side of condyle heads showed greater change in the angle on 18㎜ interincisal opening. 2. In the patient group, the condyle head of affected side was located superiorly to that of normal side on centric occlusion and the discrepancy of condular positional height was increased after 18㎜ interincisal opening. 3. The distances from medial pole of condylar head to triangular fossa of temporal bone were same on both right and left side in normal group, however, in the patient group, the distance of affected side was wider than that of opposite side on centric occusion and became narrower than the opposite side on 18㎜ interincisal opening. 4. The distances of posterior joint space were same on both right and left side. The distance t lateral pole 1/3 of condyle head was similar to that on transcranial view on centric occlusion in normal group. 5. The distances of posterior joint space were narrower in patient group than in normal group. 6. Conclusively, the affected condylar head of patient showed postero-latero-superior displacement on centric occlusion and larger range of rotational movement on 18㎜ interincisal opening.

• 대한소아치과학회지
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• 제24권1호
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• pp.301-312
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• 1997

The purpose of this study was to evaluate the analgesic effect on pulp induced by pulsed Nd : YAG laser according to the power density, irradiated time and the method of application (Non-contact vs contact) in vivo. Experiments were carried out on 90 volunteers who have sound 4 canines. Each canine was grouped by the intensity and the time of irradiation of pulsed Nd : YAG laser was measured. Mean EPT response(units) was measured at 5 min, 30 min, and 60 min after irradiation with various intensity(1.5-3W, 15-30Hz), irradiated time (1.5min, 3min), and application method (Non-contact and contact). The results were as follows: 1. 5 minutes after irradiation, the mean EPT response(units) was increased by 32 % in the non-contact method and by 35% in the contact method of application. Which showed significant difference in mean EPT response(units) compared to not-lased canine in each groups(P<0.05). 2. The mean EPT response(units) with irradiating condition according to the various laser intensity, and the irradiation time stastically did not show significant difference in each groups as time elapsed. 3. There was no significant difference between the non-contact and contact method in the mean EPT response(units). 4. The mean EPT response(units) returned to the baseline value within 30 miuntes. In regard to the above results, the analgesic effect on pulp induced by pulsed Nd : YAG laser resulted a slight increase of pulpal pain threshold, but it was not as high as to replace the role of drug analgesia as whole. This technique can be used for inducing pulpal analgesia as adjunct to other pain control methods and is needed to develop better analgesic effects.

• 인터넷정보학회논문지
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• 제6권5호
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• pp.73-83
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• 2005

본 논문에서는 착용형 컴퓨터를 위한 촉각 사용자 인터페이스 및 이를 활용한 개선된 입력알고리즘을 제안한다. 유비쿼터스 환경의 도래에 따른 차세대 PC의 진화 방향은, 인간이 느끼는 색상, 빛의 밝기, 소리, 향기, 맛, 감촉 등의 오감정보의 효과적인 융합과 재현을 목표로, 사용자 중심의 인간-기계 관계의 형성으로 나아가고 있다. 그러나 이러한 기능의 다양함과는 별개로, H/W플랫폼의 진화 방향은 항상 휴대가 간편하도록 소형화, 경량화 및 착용화 형태로 개발되어지고 있다. 이러한 차세대 PC의 소형화 및 경량화 관련 진화에 가장 큰 걸림돌이 되는 부분은 사용자 입출력 장치로서, 기존의 키보드 및 모니터 등의 장치를 활용한 사용자 인터페이스에는 소형화의 한계가 존재하고 있는 실정이다. 본 논문에서는 이러한 소형화, 경량화 및 착용화를 위한 새로운 방법의 사용자 입력장치 및 입력알고리즘을 제안한다. 또한 기존에 제안되어진 유사 장치와의 비교 분석을 통한 제안시스템 및 알고리즘의 실효성을 평가한다.

• 인문언어
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• 제8집
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• pp.265-289
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• 2006

The geographical characteristics of Yeongdong(永同) the southernmost part of the Chungcheongbukdo province, has attracted attention among the academic circle as one of the dialectal contact regions since it adjoins the Gyeongsang and Jeolla dialects. Unlike the local language in Mooju (Jellado dialect) adjacent to the Southwest part, the local language in Yeongdong is quite different from that of Kimcheon (Gyeongsang dialect). More specifically, it is noteworthy that the boundary line of the Gyeongsang dialect is found in this region, which is different from the administrative division. In other words, the local language in Yeongdong is divided into the Chungcheong dialect and the Gyeongsang dialect, and furthermore each dialect region still has the characteristics of the other region's dialect. For example, the phonological structure of Yeongdong Chungcheongdo dialect has very unique characteristics of the fudged dialect, which is seemingly influenced by the Gyeongsang dialect. The present study is to define the bottom boundary line of the southeast area of the Chungcheong dialect by identifying the boundary line between the Gyeongsang dialect and the Chungcheong dialect, and to clarify its specific sound system generated by the contact of these two dialects. For this, the author collected and analyzed data of the local language around Yeongdong and adjacent areas. It was found that Cheongwha-ri, Deokjin-ri, and Sanjeo-ri at Yeongsan-myeon, and Mugeunjeom, Sangga-ri, and Jungga-ri at Yeongdong-eup, among the regions that belongs to Chungcheong dialect within the local language of Yeongdong, show the characteristics of the Gyeongsang dialect. Accordingly, the western areas of these villages become the southeast boundary line of the Chungcheong dialect. Also, the unique phonological characteristics of the Yeongdong Chungcheong dialect is affected by the Gyeongsang dialect, among which "rhythms, y deletion, nasal phoneme deletion, and w deletion" appeared. It is thought to be the unique fudged dialectal phenomenon that appeared only in this region. The research result is expected to be of some help in finding out various aspects of dialectal contacts as well as clarifying the phonological features of the local language in Yeongdong, and thereby contributing to exact divisioning of the Chungcheong dialect.

• 한국정보통신학회논문지
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• 제9권3호
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• pp.493-497
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• 2005

본 논문은 무선의 임베디드 시스템 환경에서, VoIP 시스템을 구성하는 프로토콜 요소 중의 하나인 SIP를 이용한 User Agent의 구현에 관한 연구이다. User Agent는 설정 블록과, 주변 장치를 제어하기 위한 디바이스 쓰래드 블록, SIP 메시지를 처리하기 위한 SIP 스택 블록으로 구성하였다. 디바이스 쓰래드는 RTP 쓰래드 블록과 사운드 카드 처리 블록으로 구성하였으며, SIP 스택은 프락시 이벤트를 처리하는 워커 쓰래드 블록과 SIP 메시지를 전송하여 처리하는 SIP 트랜시버 및 SIP 쓰래드 블록으로 구성하였다. 하드웨어 플랫폼은 Intel XScale PXA25S 프로세서 기반에 플래쉬 메모리, SDRAM, AC'97 오디오 코덱, 무선 랜카드와 연결된 PCMCIA 소켓이 내장된 보드를 구성하였으며, 오디오 입출력으로 마이크로폰과 헤드폰을 사용하였다. 본 연구의 실험을 위한 타겟 시스템 구성은 임베디드 리눅스 커널 2.4.19를 포팅하였다. 임베디드 시스템의 자원 효율을 높이고자, User Agent의 속성과 SIP 메소드의 기능을 최소화하였고, TCP를 배제하여, 주변 장치 제어를 최소화함으로써, 자원의 소비를 $12.9\%$ 절감할 수 있었다.

• 한국치위생학회지
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• 제17권3호
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• pp.395-404
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• 2017

Objectives: The purpose of this study was to identify the effects of music intervention on the patient's fear and anxiety during scaling. Methods: 360 patients who had visited W University dental hygiene laboratory were selected as study subjects and divided into experiment group and control group. Results: Study results showed that the control group (71.9%) and the experimental group (75.1%) had experiences avoiding dental treatment due to fear. In the control group (37.6%) and experimental group (40.6%), the highest influencing factor was the sound of machine and followed by pain. The experimental group preferred classical music, followed by pop songs, trot music and instrumental music. In the experimental group (83.3%), fear and anxiety were alleviated by music, and 77.9% of the patients mentioned they would recommend music for scaling to other patients. There was an interaction effect (p=0.014) between the groups before and after the measurement of the lowest blood pressure. There was a significant difference in pulse before and after pulse measurement (p=0.000). There was a significant difference in respiration between groups (p=0.042) and before and after respiration (p=0.030). Conclusions: Study results showed that music intervention that utilizes music during scaling showed significant effects on the alleviation of fear and anxiety, affecting Pulse number among vital signs. Therefore, more systematic program is to be required to alleviate dental fear and anxiety with music therapy not only for scaling, but also for dental clinic in the future.

• 대한음성학회:학술대회논문집
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• 대한음성학회 2000년도 7월 학술대회지
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• pp.166-177
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• 2000

The purpose of this study was to create letters for of nonliterary Pulang tribe in Thailand those who immigrant from China. illiterate Pulang tribe hand down their tradition by primary oral culture therefore their tradition can't initiate and keep, moreover, it may disappear throughout history. So it is expected to crusade against unlettered people. The scheme of research adopted in this study was a minority race who habitate at the northern Machan, Chiangrai in Thailand. It is not only analysis of language but also the eradication of literacy and the research based on linguistic, ethnolinguistic, and primary oral culture. Five Pulang people who live in that area were chosen for creating letters. By using the I. P. A., after each word was listen to their pronunciation one by one it was described and repeated this process several times; the material words and humanbody were pointed in front of them while other words were described by gesture. For final description, number of people were in the lineup for listening the sound of words and phrases to sentences. In the first stage, it was an analysis segmental of Pulang: vocoid, contoid and diphthong were described with each sample syllables and words. The suprasegmental were studied with intonation and juncture of the words in the second stage. Two words were compared and different meanings within their intonation and juncture were shown. At the end of this part, each case of phonemic or morphophonemics representation described the juncture in the words. In the third stage, minimal pairs were analyzed with vowels and consonants and described in free variation based on words. In the last stage, syllable structure in open syllable and closed syllable was studied and then each syllable of its structure was analyzed with samples. There were thirty-two phonemes in apong Pulang as follows: seven vocoids; a, i, e, o, u, ${\ae}$, and $\wedge$, one diphthong; wu, 24 contoids; b, c, d, f, g, h, j, k, k, 1, m, n, ${\eta}, {\;}p^{h}$, p, p, r, s, s, sh, t, t, w, and y. Their pronunciations of p, s, d, $p^{h}$, j, and t are frequently used in speech and are unique in triphthong. Moreover, most of the words used initial and final consonant cluster.

• 소성∙가공
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• 제16권4호
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• pp.293-298
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• 2007

Recently, there is a need to produce a large forged part for the flight, shipping, some energies, and military industries, etc. Therefore, an open die forging technique of cast ingots is required to obtain higher quality of large size forged parts. Cogging process is one of the primary stages in many open die forging processes. In the cogging process prior to some open die forging processes, internal cavities have to be eliminated for defect-free. The present work is concerned with the elimination of the internal cavities in large ingots so as to obtain sound products. In this study, hot compression tests were carried out to obtain the flow stress of cast microstructure at different temperature and strain rates. The FEM analysis is performed to investigate the overlap defect of cast ingots during cogging stage. The measured flow stress data were used to simulate the cogging process of cast ingot using the practical material properties. Also the analysis of cavity closure is performed by using the $DEFORM^{TM}-3D$. The calculated results of cavity closure behavior are compared with the measured results before and after cogging, which are scanned by the X-ray scanner. From this result, the criteria for deformation amounts effect on the cavity closure can be investigated by the comparison between practical experiment and numerical analysis.

• 소성∙가공
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• 제27권1호
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• pp.5-11
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• 2018

Direct energy deposition (DED) technique uses a laser heat source to deposit a metal layer on a substrate. Many researchers have used the DED technique to study the hardfacing of molds and dies. The aim of this study is to obtain high surface hardness and a sound bonding between the AISI M4 deposits and a substrate utilizing a mixed powder that contains M4 and AISI P21 powders. To prevent interfacial cracks between the M4 deposits and the substrate, the mixed powder is pre-deposited onto a JIS S45C substrate, before the deposition of M4 powders. Interfacial defects occurring between the deposits and substrate and changes in the microhardness of the intermediate layer were examined. Observations of the cross-sections of deposited specimens revealed that the interfacial cracks appeared in samples with one and two mixed layers regardless of the mixture ratio. However, the crack was removed by increasing the mixture ratio and the number of intermediate layers. Meanwhile, the microhardness in the mixed layer was found to decrease with increasing ratio of P21 powder in the mixture and that in the upper region of the deposited layers was approximately 800 HV, which was attributed to various alloying elements in the M4 powder.