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

• 대한치과교정학회지
• /
• 제46권6호
• /
• pp.379-385
• /
• 2016

Objective: Forced eruption has been proposed for the reconstruction of deficient bone and soft tissue. The aim of this study was to examine the changes in the alveolar ridge width and the vertical levels of the interproximal bone and papilla following forced eruption. Methods: Patients whose hopeless maxillary anterior teeth were expected to undergo severe bone resorption and soft tissue recession upon extraction were recruited. In addition, patients whose maxillary anterior teeth required forced eruption for restoration due to tooth fracture or dental caries were included. Before and after forced eruption, the interproximal bone height was measured by radiographic analysis, and changes in the alveolar ridge width and the interproximal papilla height were measured with an acrylic stent. Results: This prospective study demonstrated that the levels of the interproximal alveolar bone and papilla were significantly increased by 1.36 mm and 1.09 mm, respectively, in the vertical direction. However, the alveolar ridge width was significantly reduced by an average of 0.67 mm in the buccolingual direction. The changes in the level of the interproximal alveolar bone and papilla were positively correlated. Conclusions: Although the levels of the interproximal bone and papilla were significantly increased, the alveolar ridge width was significantly decreased following forced eruption. There was a modest positive and significant correlation between the changes in the height of the interproximal alveolar bone and the papilla. Based on our findings, modification of vertical forced eruption should be considered when augmentation of the alveolar ridge width is required.

• Journal of Periodontal and Implant Science
• /
• 제47권1호
• /
• pp.51-63
• /
• 2017

Purpose: Following tooth extraction, alveolar ridge preservation (ARP) can maintain the dimensions of ridge height and width. Although previous studies have demonstrated the effects of ARP, few if any studies have investigated the compressive force applied during grafting. The aim of this study was to determine the effects of different compressive forces on the graft materials during ARP. Methods: After tooth extraction, sockets were filled with deproteinized bovine bone mineral with 10% porcine collagen and covered by a resorbable collagen membrane in a double-layered fashion. The graft materials were compressed using a force of 5 N in the test group (n=12) and a force of 30 N in the control group (n=12). A hidden X suture was performed to secure the graft without primary closure. Cone-beam computed tomography (CBCT) was performed immediately after grafting and 4 months later, just before implant surgery. Tissue samples were retrieved using a trephine bur from the grafted sites during implant surgery for histologic and histomorphometric evaluations. Periotest values (PTVs) were measured to assess the initial stability of the dental implants. Results: Four patients dropped out from the control group and 20 patients finished the study. Both groups healed without any complications. The CBCT measurements showed that the ridge volume was comparably preserved vertically and horizontally in both groups (P>0.05). Histomorphometric analysis demonstrated that the ratio of new bone formation was significantly greater in the test group (P<0.05). The PTVs showed no significant differences between the 2 groups (P>0.05). Conclusions: The application of a greater compressive force on biomaterials during ARP significantly enhanced new bone formation while preserving the horizontal and vertical dimensions of the alveolar ridge. Further studies are required to identity the optimal compressive force for ARP.

• 한국자원식물학회지
• /
• 제18권1호
• /
• pp.22-31
• /
• 2005

콩의 논 재배시 생육반응은 밭에서와는 다른 결과가 예상되므로, 논재배 콩의 휴립조건에 따른 생장분석을 분석 하고자 화엄 풋콩 등 5품종을 고휴와 평휴로 재배하여 생육반응을 분석한 결과는 다음과 같다. 휴립조건에 따른 콩의 지상부 생육은 경장의 경우 전 생육기에서 평휴재배시 높은 경향을 보이지만, 분지수와 경직경은 생육 후기로 갈수록 고휴조건에서 큰 경향을 보였다. 그러나 지상부 생육은 재배조건에 따른 차이보다, 품종간 차이가 보다 뚜렷하게 나타났다. 논에서 휴립 조건에 따른 생육단계별 콩의 지상부생육은, 생육초기인 V5 stage에서는 평휴재배시 건물 생산능력이 고휴재배시 보다 높았으나, 생육이 진전될수록 고휴로 재배할 때 건물중 생산이 높았으며, 전 생육기간 동안 품종별 차이가 뚜렷하였다. 재배조건에 따른 콩의 논에서의 지하부의 생육은, V5, R2 및 R5 stage 등 전 생육기간동안 고휴 재배시 지하부의 생육이 평휴재배조건 보다 왕성하였으며, 재배방법에 따른 고휴재배 효과는 나타나지 않았으나, 품종간 차이는 컸다. T/R율은 평휴로 재배할 경우 높았고, 재배방법에 따른 고휴재배 효과는 나타나지 않았으나, 품종간 차이는 인정되었다.

• 한국통신학회논문지
• /
• 제27권4A호
• /
• pp.345-355
• /
• 2002

본 논문에서는 지문영상의 향상을 위한 방향성 필터링의 새로운 기법을 제안한다. 지문영상은 융선의 규칙적인 열의 방향성 맵으로 구성되어 있으며, 융선의 주방향성은 지문영상의 주요 특징점을 추출하기 위한 융선의 연결이나 잡음의 제거 등 지문영상의 전처리과정에 매우 중요하다. 방향성대역 통과 필터뱅크(Directional Filter Bank ; FB)는 입력영상을 주파수의 성분이 아닌 방향성 성분으로 분해한 다음, 이 대역영상으로부터 원영상을 완전하게 복원하는 필터이다. 본 논문은 DFB를 이용하여 지문영상을 방향성 대역 영상으로 분해하여 이를 처리한 후 복원함으로써 지문영상을 향상시키는 알고리듬을 제안한다.

• 구강회복응용과학지
• /
• 제19권3호
• /
• pp.139-151
• /
• 2003

This study was to evaluate and to compare the compressive strength and the displacement effecting the abutment or the residual ridge which are transformed by the angle and the heights of the konus denture inner crown when restorating the unilateral konus denture by using the mandibular canine and the 1st premolar as an abutment. The author made 9 different models for different inner crown heights and konus angles. The inner crown height were divided to 5mm, 6mm, and 7mm and konus angles was divided to $4^{\circ}$, $6^{\circ}$, and $8^{\circ}$. And then in each model, 5kg of $15^{\circ}$ mesial load was stressed on the central fossa of the 1st premolar and the 1st molar. The stresses and displacement were measured using the finite element analysis. The results were as follows 1. The maximum compressive strength was shown on the connective area of the abutment and the denture base. 2. As the angle of the inner crown becomes increased, the compressive strength was shown smaller. 3. As the height of the inner crown becomes increased, the maximum compressive strength was shown smaller while the compressive strength of the root apex and the residual ridge showed larger. 4. When the stress was loaded only on the 1st premolar, the more compressive strength was concentrated on the root apex area of the 1st premolar. 5. When the stress was loaded only on the 1st premolar, the compressive strength was concentrated uniformly on the abutment and the residual ridge. 6. When the stress was loaded only on the 1st molar, the maximum displacement was shown on the distal part of the residual ridge.

• 한국환경생태학회지
• /
• 제18권2호
• /
• pp.150-157
• /
• 2004

백두대간 능선부의 식생구조를 파악하고자, 백두대간 수령-소사고개구간 능선부에 10개의 방형구(500$m^2$)를 설정하여 식생을 조사하였다. 식물군집을 분류한 결과 10개 조사구는 떡갈나무-물푸레나무군집, 신갈나무-물푸레나무군집, 신갈나무군집의 3개 군집으로 분류되었다. 백두대간 수령-소사고개 구간의 능선부는 대부분 신갈나무가 우점하고 있었으며, 일부에서 해발고가 낮은 지역에서 떡갈나무와 물푸레나무 등이 혼효하고 있었다. 조사지의 군집별 종다양성지수는 1.7295∼2.6525 범위로 백두대간에 위치한 국립공원들의 능선부 식생구조와 비슷하였다. 산림청에서 희귀식물로 등록한 흰참꽃나무가 삼봉산 주변 바위틀에서 여러 개체가 자라고 있었으며, 지속적인 모니터링을 함으로써 훼손대책을 강구할 필요가 있다.

• Nuclear Engineering and Technology
• /
• 제49권6호
• /
• pp.1226-1233
• /
• 2017

Measurements of the isotopic contents of spent nuclear fuel provide experimental data that are a prerequisite for validating computer codes and nuclear data for many spent fuel applications. Under the auspices of the Organisation for Economic Co-operation and Development (OECD) Nuclear Energy Agency (NEA) and guidance of the Expert Group on Assay Data of Spent Nuclear Fuel of the NEA Working Party on Nuclear Criticality Safety, a new database of expanded spent fuel isotopic compositions has been compiled. The database, Spent Fuel Compositions (SFCOMPO) 2.0, includes measured data for more than 750 fuel samples acquired from 44 different reactors and representing eight different reactor technologies. Measurements for more than 90 isotopes are included. This new database provides data essential for establishing the reliability of code systems for inventory predictions, but it also has broader potential application to nuclear data evaluation. The database, together with adjoint based sensitivity and uncertainty tools for transmutation systems developed to quantify the importance of nuclear data on nuclide concentrations, are described.

• 대한치과보철학회지
• /
• 제54권2호
• /
• pp.110-119
• /
• 2016

목적: 본 연구는 임플란트 지대주의 체결부 길이와 골정에 대한 고정체 상단의 위치에 따라서, 하중 적용 시 고정체, 지대주, 나사 및 골에서의 응력 분포에 어떤 변화가 나타나는지 평가해 보고자 하였다. 재료 및 방법: 원추형 사면과 육각 기둥 형태의 회전저항구조를 갖는 내측 연결형 임플란트에서 지대주의 체결부 길이가 2.5 mm, 3.5 mm, 4.5 mm인 경우와 각 경우에서 고정체 상단이 골정과 같거나 골정보다 2 mm 상방에 위치할 때를 상정하여, 유한요소분석을 위한 모델을 총 6개 형성하였다. 각 경우에서 170 N의 30도 경사하중을 적용하였다. 결과: 6개의 유한요소분석 모델 모두에서, 임플란트는 고정체와 지대주의 체결 상단 부위에서, 주위 골에서는 골정 부근에서 최대 응력 값을 나타냈다. 지대주의 체결부 길이가 길어질수록, 주어진 하중에서 발생되는 고정체, 지대주, 나사 및 골에서의 최대 응력 값은 줄어들었다. 고정체 상단이 골정과 동일한 높이에 있는 경우보다 골정 2 mm 상방에 위치하는 경우에서 지대주의 체결부 길이가 길어질수록 모든 부위에서 더 큰 비율로 최대 응력 값의 감소를 나타내었다. 결론: 지대주의 체결부 길이가 길어질수록 모든 부위에서 주어진 하중에 따른 최대 응력 값이 줄어드는 것을 알 수 있었고, 임플란트의 기계적 및 생물학적 합병증 예방에 도움이 될 수 있을 것으로 판단된다.

• 전자공학회논문지B
• /
• 제33B권5호
• /
• pp.118-126
• /
• 1996

In object analysis by image processing, finding lines plays a universal role. And these lines can be easily found by detecting ridges and valleys in digital gray scale images. In this paper, a new method of detecting ridges and valleys by using local min/max operations was presented. This method detects ridges and valleys of desired width by using erosion and dilation properties of local min/max operations, and requires no information of ridge or valley direction. Therefore the method is efficient and computationally simple in comparision with the conventional analytical method.