도재 라미네이트의 두께의 따른 레진 시멘트의 표면경도에 관한 연구

강석구,동진근,진태호,Kang Seok-Koo,Dong Jin-Keun,Jin Tai-Ho 대한치과보철학회 1993 대한치과보철학회지 Vol.31 No.4

The purpose of this study was to evaluate the effect of porcelain laminate thickness on polymerization of resin cement. G-Cera resin bonding system(G-C int., Japan) was used in this study and Heliolux II (Vivadent, Austria) was used for polymerization of resin cement. The thickness of porcelain laminates used in this study were 0.5mm, 1.0mm and 1.5mm and the degree of polymerization of resin cement was measured by microhardness theater(Matsuzawa, Model MXT-70, Japan). The obtained results were as follows : 1. The surface hardness of resin cements increaing the thickness of poreclain laminate was decreased. 2. The surface hardness of resin cements increasing the curing time was decreased.

RCP 시나리오 및 전지구 수문 모형을 활용한 아시아 미래 수문인자 예측

김다운,김다은,강석구,최민하,Kim, Dawun,Kim, Daeun,Kang, Seok-koo,Choi, Minha 한국수자원학회 2016 한국수자원학회논문집 Vol.49 No.6

According to the 4th and 5th assessment of the Intergovernmental Panel on Climate Change (IPCC), global climate has been rapidly changing because of the human activities since Industrial Revolution. The perceived changes were appeared strongly in temperature and concentration of carbon dioxide ($CO_2$). Global average temperature has increased about $0.74^{\circ}C$ over last 100 years (IPCC, 2007) and concentration of $CO_2$ is unprecedented in at least the last 800,000 years (IPCC, 2014). These phenomena influence precipitation, evapotranspiration and soil moisture which have an important role in hydrology, and that is the reason why there is a necessity to study climate change. In this study, Asia region was selected to simulate primary energy index from 1951 to 2100. To predict future climate change effect, Common Land Model (CLM) which is used for various fields across the world was employed. The forcing data was Representative Concentration Pathway (RCP) data which is the newest greenhouse gas emission scenario published in IPCC 5th assessment. Validation of net radiation ($R_n$), sensible heat flux (H), latent heat flux (LE) for historical period was performed with 5 flux tower site-data in the region of AsiaFlux and the monthly trends of simulation results were almost equaled to observation data. The simulation results for 2006-2100 showed almost stable net radiation, slightly decreasing sensible heat flux and quite increasing latent heat flux. Especially the uptrend for RCP 8.5 has been about doubled compared to RCP 4.5 and since late 2060s, variations of net radiation and sensible heat flux would be significantly risen becoming an extreme climate condition. In a follow-up study, a simulation for energy index and hydrological index under the detailed condition will be conducted with various scenario established from this study. 기후변화에 관한 정부간 협의체 (Intergovernmental Panel on Climate Change; IPCC)의 4차 및 5차 보고서에 따르면 인류 활동에 의한 기후변화가 산업혁명 이후 급속하게 진행되고 있다고 한다. 기후변화는 주로 온도와 이산화탄소 농도의 변화로 감지되는데, 지난 100여년 간 지구 평균 온도는 $0.74^{\circ}C$ 상승하였으며, 대기 중 이산화탄소의 농도는 최소 800,000년 동안의 최대치를 기록하였다 (IPCC, 2007, 2014). 이러한 기후 변화는 수문학 연구에서 중요한 강수, 증발산, 토양수분 등에도 커다란 영향을 미치므로 이에 대한 꾸준한 연구가 필요하다. 따라서 본 연구에서는 아시아 지역을 대상으로 1951년부터 2100년까지의 주요 에너지 인자들에 대한 모의를 실시하였다. 전 세계적으로 다양한 분야에서 사용되고 있는 Common Land Model을 미래 예측을 위한 기반으로 활용하였으며, 강제입력자료는 기후변화에 대응하기 위하여 IPCC 5차 보고서에 소개된 가장 최신의 온실가스 시나리오인 대표농도경로 (Representative Concentration Pathway; RCP)를 활용하였다. 과거 기간에 대한 순복사량, 현열 및 잠열에 대한 검증은 Asiaflux 사이트에 속한 5개 지점의 자료를 활용하여 수행하였으며, 모든 인자들에 대하여 모형의 월별 경향성이 관측 자료와 거의 일치함을 확인하였다. 미래 기간의 모의에 대해서는 RCP 4.5 및 RCP 8.5를 활용한 모의 모두 순복사량은 거의 변화가 없었으며 현열은 대체적으로 하강하는 경향을, 이와 대조적으로 잠열의 경우에는 상승하는 경향을 나타내었다. 특히 RCP 8.5를 활용한 결과에서 이 증감폭은 더 크게 나타났으며, 2060년대 후반부터 순복사량과 현열의 변동성이 매우 커지는 등의 극한기후의 특징을 나타내는 것으로 보인다. 추후 연구에서는 본 연구를 토대로 다양한 시나리오를 활용하여 더욱 다양한 조건하에서의 에너지 인자 및 다른 수문학적 주요 인자들에 대한 모의를 수행할 예정이다.

본류 수위 급상승에 의한 지류 역류 해석

윤태훈(Yoon Tae Hoon),강석구(Kang Seok-Koo),이지송(Lee Ji Song) 대한토목학회 2002 대한토목학회논문집 B Vol.22 No.1B

서해연안 토지이용 및 토지피복 변화탐지를 위한 KOMPSAT-2 영상의 활용

선우우연 ( Woo Yeon Sunwoo ),김다은 ( Da Eun Kim ),강석구 ( Seok Koo Kang ),최민하 ( Min Ha Choi ) 대한원격탐사학회 2016 大韓遠隔探査學會誌 Vol.32 No.2

토지이용 및 토지피복변화에 대한 신뢰성 높은 평가는 수로학 및 지리학적 연구에서 침식 및 퇴적, 해안 모니터링, 생태영향평가와 같은 다양한 실질적인 사안들을 발전시켰다. 원격탐사 이미지는 시간 변화에 따른 자연 및 토지변화를 살펴보는데 있어 뛰어난 잠재력을 지니고 있다. 따라서 최근에서는 환경 모니터링을 위해 고해상도의 원격탐사 영상 이미지를 활용한 보다 정확한 연구가 요구되고 있다. 본 논문에서는 갯벌보호지역이 위치한 한반도의 전라남도, 전라북도 일부지역의 토지이용 및 토지피복 변화에 대한 맵핑 및 변화탐지 방법을 실시하였다. 이를 위하여 2008년부터 2015년에 촬영된 KOMPSAT-2 위성의 다중분광 이미지를 사용하였다. 토지이용 및 토지피복변화 맵핑은 무감독 토지분류방법으로 분석하였으며, postclassification 변화탐지 방법으로 평가하였다. 전라북도와 전라남도의 연안지역에 대한 토지이이용 및 토지피복변화에 대한 평가결과는 시간변화에 따라 큰 차이가 나타나지는 않았으나 각각 약 1.97%, 4.34% 정도의 변화를 보였다. 본 연구결과는 연구지역의 토지피복 변화 양상을 정량화 하였으며, 특히, 화소기반 분석을 통해 연안지역에 대한 KOMPSAT-2 다중분광 이미지의 효율적이고 경제적인 활용 가능성을 확인하였다. 이러한 토지이용 및 토지피복변화 정보는 연안환경 관리 및 정책결정을 위해서 환경 및 정책관리자들에게 유용할 것으로 기대된다. Reliable assessment of Land Use and Land Cover (LULC) changes greatly improves many practical issues in hydrography, socio-geographical research such as the observation of erosion and accretion, coastal monitoring, ecological effects evaluation. Remote sensing imageries can offer the outstanding capability to monitor nature and extent of land and associated changes over time. Nowadays accurate analysis using remote sensing imageries with high spatio-temporal resolution is required for environmental monitoring. This study develops a methodology of mapping and change detection in LULC by using classified Korea Multi-Purpose Satellite-2 (KOMPSAT-2) multispectral imageries at Jeonbuk and Jeonnam provinces including protected tidal flats located in the west coasts of Korean peninsula from 2008 to 2015. The LULC maps generated from unsupervised classification were analyzed and evaluated by post-classification change detection methods. The LULC assessment in Jeonbuk and Jeonnam areas had not showed significant changes over time although developed area was gradually increased only by 1.97% and 4.34% at both areas respectively. Overall, the results of this study quantify the land cover change patterns through pixel based analysis which demonstrate the potential of multispectral KOMPSAT- 2 images to provide effective and economical LULC maps in the coastal zone over time. This LULC information would be of great interest to the environmental and policy mangers for the better coastal management and political decisions.

도재 라미네이트의 두께에 따른 레진 시멘트의 표면경도에 관한 연구

강석구,동진근,진태호 원광대학교 치의학연구소 1992 圓光齒醫學 Vol.2 No.1

The purpose of this study was to evaluate the effect of porcelain laminate thickness on polymerization of resin cement. G-Cera resin bonding system(G-C int., Japan) was used in this study and Heliolux Ⅱ(Vivadent, Austria) was used for polymerization of resin cement. The thickness of porcelain laminates used in this study were 0.5㎜, 1.0㎜ and 1.5㎜ and the degree of polymerization of resin cement was measured by microhardness tester(Matsuzawa, Model MXT-70, Japan). The obtained results were as follows 1. The surface hardness of resin cements increasing the thickness of porcelain laminate was decreased. 2. The surface hardness of resin cements increasing the curing time was decreased.

전치부 하악운동양태와 과두운동 간의 관계

강석구,동진근 원광대학교 치의학연구소 1996 圓光齒醫學 Vol.6 No.2

The author performed this study to investige the relationship between condylar movements recorded with Pantronic and mandibular movements at incisal area recorded with BioEGN. For this study 24 patients with Temporomandibular disorders (TMDs) and 30 dental students without any masticatory symptoms were selected as patients group and control group, respectively. The items recorded with Pantronic(Denar Corp., USA) were immediate side-shift, progressive side-shift, orbiting path, protrusive path, and PRI. BioEGN(Bioelectric-gnathography, Bioresearch Inc., USA) were used to measure the amount of mandibular torque movement in frontal and horizontal plane and also the distance of mandibular translation at incisal area. Amount of mandibular rotational torque movement was analyzed by angle and difference between both condyles in frontal and horizontal plane. The collected data were processed with SAS program and conclusion were as follows : 1. Mean value of items recorded with Pantronic were not significantly differed between patients group and control group except the item of pantographic reproducibility index (PRI). The value of PRI 39.5 in patients group, and 29.5 in control group. 2. The amount of mandibular torque movement was not differed in early protrusive and early left excursion between patients group and control group, but in early right excursion, patients group showed more value than control group did. 3. The distance on sagittal plane in early eccentric movements were longer in patients group than those in control group, but the distance of maximal eccentric movements were not significantly differed between patients group and control group. 4. Items which showed significant correlation with PRI were progressive side-shift, and horizontal torque movement in early protrusion and right excursion. 5. The angle of protrusive path of affected side was greater than that of non-affected side in unilaterally affected patients, but the protrusive angle of preferred chewing side was not differed from that of contralateral side in control group. 6. The amount of torque movement in early protrusion and right excursion were greater in patientswith coincidence of affected side and preferred chewing side than in patients without coincidence.

한국형 유치악용 기성트레이의 개발에 관한 연구

송대성,강석구,조혜원,동진근 원광대학교 치의학연구소 1995 圓光齒醫學 Vol.5 No.2

This study was designed to develop dentulous stock trays for Koreans. The subjects of this study were 374 persons (male: 204, female: 170), age 19-28. The study casts of these subjects were made with irreversible hydrocolloid impression material in conventional stock tray. The master casts were made after impression with polysulfide rubber impression material in individual trays which was constructed from study cast. 12 measurements on the maxillary cast and 13 measurements on the mandibular cast were done with digital sliding caliper. The values were analyzed statistically by SAS and used to design new dentulous stock trays for Koreans. Maxillary casts were divided into four groups accoding to the width between buccal alveolar ridges below the contact point of first molar and second molar. The size of the new upper tray for the first group was 82㎜ in width and 60㎜ in length. The second group was 77㎜ in width and 59mm in length. The third group was 72㎜ in width and 58㎜ in length. The fourth group was 67㎜ in width and 57㎜ in length. Mandibular casts were divided into three groups according to the width between lingual alveolar ridges below the second molar. The size of new tray for the lower first group was 42㎜ in width and 55㎜ in length. The second group was 36㎜ in width and 55mm in length. The third group was 30㎜ in width and 55㎜ in length. In addition, the fit of newly designed stock trays was tested on 52 subjects with normal occlusion and obtained good results. Problems of conventional stock trays were worked out.