• 대한심미치과학회지
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• 제7권1호
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• pp.32-40
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• 1998

Alveolar ridge augmentation and preservation techniques designed to reconstruct deformed alveolar ridge now occupy a major role in esthetic dentistry. Previously, deformed alveolar ridges were filled with plastic materials(porcelain or resin) of prosthesis to restore ridge contours, which resulted in larger teeth and food impaction under the pontic base. So, prostheses of this type were unacceptable and really detectable when patients smiled. But nowadays, alveolar ridge augmentation procedures enable the dentists to provide patients with fixed prostheses that are esthetic. The development of guided tissue regeneration technique and materials also have made a major impact on extending the scope of therapeutic horizons in dentistry.

• 대기
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• 제33권1호
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• pp.49-59
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• 2023

Blocking refers to a class of weather phenomena appearing in the mid and high latitudes, whose characteristics are blocked airflow of persistence. Frequently found over the Pacific and Atlantic regions of the Northern Hemisphere, blocking affects severe weather in the surrounding areas with different mechanisms depending on the type of blocking patterns. Along with lots of studies about persistent weather extremes focusing on the specific types of blocking, a new categorization using Rossby wave breaking has emerged. This study aims to apply this concept to the classification of blockings over the Pacific and examine how different wave breakings specify the associated cold weather in the Korean peninsula. At the same time, we investigate a strongly developing ridge around the Pacific by designing a new detection algorithm, where a reversal method is modified to distinguish ridge-type blocking patterns. As result, Kamchatka blocking (KB) and strong ridge over the Central Pacific are observed the most frequently during 20 years (2001~2020) of the studied period, and anomalous low pressures with cold air over the Korean Peninsula are accompanied by blocking events. When it considers the Rossby wave breaking, cyclonic wave-breaking is dominant in KB, which generates low-pressure anomalies over the Korean Peninsula. However, KB with anticyclone wave breaking appears with the high-pressure anomalies over the Korean Peninsula and it generates the warm temperature anomaly. Lastly, the low-pressure anomalies are also generated by the strong ridge over the Central Pacific, which persists for approximately three days and give a significant impact on cold surge on the Korean Peninsula.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2019년도 학술발표회
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• pp.24-24
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• 2019

This study investigates variations in the Western Pacific Subtropical High (WPSH) and its impact on South Korean precipitation in late summer during the period between 1958 and 2017. Composite analysis reveals that precipitation occurrence is directly linked to the displacement of the WPSH western ridge, a single, large-scale feature of the atmosphere in the Pacific Ocean. When WPSH ridging is located northwest (NW) of its climatological mean position, excessive precipitation is expected in late summer due to enhanced moisture transport. On the other hand, a precipitation deficit is frequently observed when the western ridge is located in the southeast (SE). Different phases of the WPSH are associated with lagged patterns of Pacific and Atlantic atmospheric and oceanic variability, introducing the potential to predict variability in the WPSH western ridge and its climate over northern East Asia by one month. Based on the identified SST patterns, a simple statistical model is developed and improvement in the ability to predict is confirmed through a cross-validation framework. Finally, the potential for further improvements in WPSH-based predictions is addressed.

• 환경영향평가
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• 제18권5호
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• pp.313-319
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• 2009

A complex maritime resort combined marina and with course of Korea is required to improve international tourism competitiveness by taking advantage of her environmental favorable circumstances. The development of tourism, however, is focused on land-oriented that incurred lower tourism efficiency and international tourism competitiveness. In addition, the regulation of "Preliminary environmental assessment for golf courses" by the Ministry of Environment is emphasized on land geography and geology that can cause damage of tourist attractions in an island region. In particular, the development of 6th or 7th ridges in mountainous island region within 2km from the sea, that holds scenic and academic value, can go against environment-friendly by geographical and geological damage. According to the regulation for consultation for golf courses and forestry is to preserve regional ecosystem over 6th ridge, but it cannot be applicable to island region because that can form excessive slopes where marine ecosystem is required to be maintained. It, therefore, can be desirable that the development of over 6th ridge in an island region. It is suggested that continuous comparative studies of geographical and geological characteristics between land and island region will be carried on to establish feasible and reasonable development model so that balanced development of land and island, and versatile international environment-friendly maritime resort can be achieved and developed.

• 한국산림과학회지
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• 제98권5호
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• pp.584-592
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• 2009

The objective of this study was to examine the impact of pruning intensity on the vigor and cambial growth of the treated trees, and on the closure of pruning wounds for one year after pruning treatment. Two tree species, Pinus strobus and Acer palmatum, planted broadly in the urban forest of Korea were selected for the experiment. Intensity of pruning, which was estimated by proportion of removed branches, was categorized into five levels with about 10% intervals from lowest 8% up to 46%. Following parameters were examined; cambial electrical resistance (CER) and the cambial growth of trunk at 30 cm above the ground for the years before and after pruning, the cambial growth of stem at 1.5 cm above the branch bark ridge (BBR) of the pruned branch, and closure of pruning wound for one year after pruning. Tree vigor inferred from CER had a tendency to be weakened as pruning intensity increased in P. strobus, while that of A. palmatum was not affected. The trunk growth decreased significantly when the pruning intensity was higher than 30% in both species. The closure of individual pruning wound was related more to the cambial growth of stem at 1.5 cm above BBR than to the pruning intensity. Comparing the closure rate of pruning wound for one year, P. strobus with 72.1% was faster than A. palmatum with 39.3%, which corresponded with the rate of cambial growth of the two species.

• 한국농공학회논문집
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• 제60권1호
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• pp.111-120
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• 2018

The purpose of this study was to develop a ridge regression (RR) model to estimate BOD and TP load using runoff weighted value. The concept of runoff weighted value, based on distributed curve-number (CN), was introduced to reflect the impact of land covers on runoff. The estimated runoff depths by distributed CN were closer to the observed values than those by area weighted mean CN. The RR is a technique used when the data suffers from multicollinearity. The RR model was developed for five flow duration intervals with the independent variables of daily runoff discharge of seven land covers and dependent variables of daily pollutant load. The RR model was applied to Heuk river watershed, a subwatershed of the Han river watershed. The variance inflation factors of the RR model decreased to the value less than 10. The RR model showed a good performance with Nash-Sutcliffe efficiency (NSE) of 0.73 and 0.87, and Pearson correlation coefficient of 0.88 and 0.93 for BOD and TP, respectively. The results suggest that the methods used in the study can be applied to estimate pollutant load of different land cover watersheds using limited data.

• 한국환경과학회지
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• 제26권10호
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• pp.1111-1124
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• 2017

This study aimed to understand the distribution of vegetation in the eastern and western sides of the Baekdudaegan (ridge) dividing the Odaesan National Park, as influenced by its topography and climate. The actual vegetation, topography and climate for each side were used in the overlay analysis. The results of the analysis of actual vegetation showed a high distribution rate of Quercus mongolica forest on both the eastern and western sides. On the eastern side, the distribution rate of Pinus densiflora forest and P. densiflora-Q. variabilis forest was high, while the western side had a high distribution rate of deciduous broad-leaved tree forest and Abies hollophylla forest. A clear trend was identified for vegetation distribution with respect to elevation but not with respect to slope or aspect. The results of micro-landform analysis showed that the P. densiflora forests in the ridge and slope and the deciduous broad-leaved tree forest in the valley were respectively distributed with a high ratio. In terms of climate, the eastern side revealed an oceanic climate, with a relatively high average annual temperature, while the western side was characterized by relatively high average annual humidity and average annual precipitation. The distribution rate of P. densiflora forest was found to be high on the eastern side of the mountain range.

• 한국건설관리학회논문집
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• 제16권5호
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• pp.77-85
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• 2015

헤도닉 가격 모형은 부동산 가격에 영향을 미치는 여러 요소를 모델링하는데 활용되는 대표적 방법이다. 부동산 가격은 전용면적, 방의 개수, 주차공간과 같은 내재적 속성 뿐 아니라 주변 선호/비선호시설의 존재여부에 따라 영향을 받는다. 주변 입지시설의 경우, 그 영향을 파악하기 위해서는 해당 부동산과의 인접거리를 설명변수로 사용하게 된다. 그러나 다수의 입지시설이 인접해 있는 경우에는 설명 변수 간 다중공선성이 발생하는 문제가 존재한다. 본 연구에서는 분산팽창지수 및 능형회귀분석을 이용해 다중공선성을 파악하고 유의한 설명변수를 선별하는데에 활용하였다. 이들 기법을 서울시 구로구 아파트들에 적용한 결과, 전철 차량 기지, 디지털 단지 및 위도에 해당하는 변수간의 다중공선성을 파악하였으며, 능형회귀분석을 통해 적합한 변수들을 체계적으로 선정할 수 있었다. 본 사례를 통해 상기 기법들이 더 정확하고 적정한 헤도닉 가격 모형을 구축하는데 중요한 보완적 기능을 해준다는 것을 알 수 있다.

• 대한심미치과학회지
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• 제32권1호
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• pp.16-22
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• 2023

상악 전치부 임플란트 수복의 성공에 있어서 심미적인 요소는 매우 중요한 부분입니다. 하지만 심미적인 결과를 얻는 것은 쉬운 일이 아니며 특히 치주염으로 인해 치조골 소실이 심하게 발생한 경우라면 더욱 그러합니다. 상악 전치부의 경우, 발치 직후부터 시작되는 치주 조직의 위축이 심미적 수복을 방해하므로 이를 최소화하기 위해 발치 즉시 임플란트를 시행하기도 합니다. 하지만 치조골 소실이 심한 경우 발치 즉시 식립은 심미적 실패를 가져올 가능성이 있고, 이런 결과는 돌이킬 수 없는 문제를 야기합니다. 그래서 치조제 보존술(Alveolar ridge preservation)을 시행하고 이후에 임플란트를 식립하는 방법으로 접근하기도 합니다. 2019년 JCP에 발치 후 임플란트 식립 시기와 발치와 처치에 대한 유럽치주학회의 consensus가 수록되어 있는데 여기서도 '심미적으로 중요한 부위에서 순측 치조골의 소실이 심하게 발생한 경우 치조제 보존술을 고려해야 한다고 언급하고 있습니다. 치조제 보존술을 하게 되면 primary closure가 어렵기 때문에 open membrane technique으로 이차치유를 유도하거나 FGG, CT graft를 시행하게 됩니다. 하지만 이차 치유 과정은 골재생에 부정적인 영향을 줄 수 있고, 연조직 이식은 환자와 술자에게 부담이 될 수 있습니다. 반면 치조골 결손이 심한 발치와에 있는 육아 조직(Granulation tissue)을 이용하게 되면 연조직 이식 없이도 primary closure를 얻을 수 있습니다. 또한 육아 조직에 조직 재생에 도움이 될 수 있는 줄기세포가 함유되어 있다는 연구들이 있습니다. 이를 근거로 치조골 및 연조직 결손이 심한 상악 전치부 치아를 육아 조직을 이용한 치조제 보존술을 통해 임플란트 수복을 시행하였습니다. 결손이 심한 발치와임에도 불구하고 비교적 심미적인 임플란트 수복 결과를 얻을 수 있었습니다.

• Journal of Periodontal and Implant Science
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• 제46권6호
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• pp.415-425
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• 2016

Purpose: The present study investigated the impact of 2 different suture techniques, the conventional crossed mattress suture (X suture) and the novel hidden X suture, for alveolar ridge preservation (ARP) with an open healing approach. Methods: This study was a prospective randomized controlled clinical trial. Fourteen patients requiring extraction of the maxillary or mandibular posterior teeth were enrolled and allocated into 2 groups. After extraction, demineralized bovine bone matrix mixed with 10% collagen (DBBM-C) was grafted and the socket was covered by porcine collagen membrane in a double-layer fashion. No attempt to obtain primary closure was made. The hidden X suture and conventional X suture techniques were performed in the test and control groups, respectively. Cone-beam computed tomographic (CBCT) images were taken immediately after the graft procedure and before implant surgery 4 months later. Additionally, the change in the mucogingival junction (MGJ) position was measured and was compared after extraction, after suturing, and 4 months after the operation. Results: All sites healed without any complications. Clinical evaluations showed that the MGJ line shifted to the lingual side immediately after the application of the X suture by $1.56{\pm}0.90mm$ in the control group, while the application of the hidden X suture rather pushed the MGJ line slightly to the buccal side by $0.25{\pm}0.66mm$. It was demonstrated that the amount of keratinized tissue (KT) preserved on the buccal side was significantly greater in the hidden X suture group 4 months after the procedure (P<0.05). Radiographic analysis showed that the hidden X suture had a significant effect in preserving horizontal width and minimizing vertical reduction in comparison to X suture (P<0.05). Conclusions: Our study provided clinical and radiographic verification of the efficacy of the hidden X suture in preserving the width of KT and the dimensions of the alveolar ridge after ARP.