• Journal of the Korean Geotechnical Society
• /
• v.26 no.10
• /
• pp.69-79
• /
• 2010

To detect abnormal events in slopes, Principal Component Analysis (PCA) is applied to the slope that was collapsed during monitoring. Principal component analysis is a kind of statical methods and is called non-parametric modeling. In this analysis, principal component score indicates an abnormal behavior of slope. In an abnormal event, principal component score is relatively higher or lower compared to a normal situation so that there is a big score change in the case of abnormal. The results confirm that the abnormal events and collapses of slope were detected by using principal component analysis. It could be possible to predict quantitatively the slope behavior and abnormal events using principal component analysis.

• Journal of Korean Society of societal Security
• /
• v.1 no.4
• /
• pp.65-71
• /
• 2008

This paper presents the characteristics of internal erosion of embankment slopes due to the localized heavy rain. In this study, the existing analysis methods of filter performance in embankment materials were reviewed. Based on the theoretical concept of filter conditions to prevent particles from being carried in from the adjacent embankment materials, new analysis method was suggested. According to the new analysis method for filter performance, experimental programs were carried out to investigate the filter performance for controlling and sealing any leak which develops through the embankment materials as a result of internal erosion. Three sets of small scale laboratory tests were carried out with changing the main influence factors such as rainfall intensity, gradient of slope, embankment material condition. It was found that the new analysis method for filter performance to prevent particles from being carried in from the adjacent embankment materials was more capable approach to design the filter materials in embankment slopes. The new criterion or method for satisfactory filter performance, therefore, was recommended.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.7 no.3
• /
• pp.108-117
• /
• 2004

Soil particles from rainfall flow into reservoir and give lots of influence in water quality because the geological conditions and landcover characteristics of Imdong watershed have a weakness against soil loss. Especially, reservoir slant is indicated by the main source area of soil loss. This study selected RUSLE model that could apply GIS and satellite image to evaluate the contribution rate of soil loss in reservoir slant. And we carried out an on-the-spot survey for the range, width and condition of reservoir slant that give much influences to the accuracy of soil loss. As the result of evaluation to the influence of soil loss in reservoir slant, it showed 2.64% in comparison with Imdong watershed. In view of these results, the influence of soil loss in reservoir slant was evaluated in low comparing with Imdong watershed relatively.

• Restorative Dentistry and Endodontics
• /
• v.23 no.2
• /
• pp.537-549
• /
• 1998

The purpose of this study was to evaluate the influence of root resection and retrograde cavity preparation methods on the apical leakage in endodontic surgery. To investigate the effect of various root resection and retrograde cavity preparation methods on the apical leakage, 71 roots of extracted human maxillary anterior teeth and 44 mesiobuccal roots of extracted human maxillary first molars were used. Root canals of the all the specimens were prepared with step-back technique and filled with gutta-percha by lateral condensation method. Three millimeters of each root was resected at a 45 degree angle or perpendicular to the long axis of the tooth according to the groups. Retrograde cavities were prepared with ultrasonic instruments or a slow-speed round bur, and occlusal access cavities were filled with zinc oxide eugenol cement. Three coats of clear nail polish were placed on the lateral and coronal surfaces of the specimens except the apical cut one millimeter. All the specimens were immerged in 2% methylene blue solution for 7 days in an incubator at $37^{\circ}C$. The teeth were dissolved in 14 ml of 35% nitric acid solution and the dye present within the root canal system was returned to solution. The leakage of dye was quantitatively measured via spectrophotometric method. The obtained data were analysed statistically using two-way ANOVA and Duncans Multiple Range Test. The results were as follows: 1. No statistically significant difference was observed between ultrasonic retrograde cavity preparation method and slow-speed round bur technique, without apical bevel (p>0.05). 2. Ultrasonic retrograde preparation method showed significantly less apical leakage than slow-speed round bur technique, with bevel (p<0.0001). 3. No statistically significant difference was found between beveled resected root surface and non-beveled resected root surface, with ultrasonic technique (p>0.05). 4. Non-beveled resected root surface showed significantly less apical leakage than beveled resected root surface, with slow-speed round bur technique (p<0.0001). 5. No statistically significant difference in apical leakage was found between the group of retrograde cavity prepared parallel to the long axis of the tooth and the group of one prepared perpendicular to the long axis of the tooth (p>0.05). 6. Regarding isthmus preparation, ultrasonic retrograde preparation method showed significantly less apical leakage than slow-speed round bur technique, in the mesiobuccal root of maxillary molar, without bevel (p<0.0001).

• The Journal of Engineering Geology
• /
• v.21 no.1
• /
• pp.57-64
• /
• 2011

Three-dimensional slope stability analysis was applied to a failed dual-lithology slope containing both granite and an andesitic dyke, taking account of the differences in shear strength of the different lithologies. A direct shear test of the soil-rock boundary was performed to examine the shear strength of two different types of failure surfaces within different lithologies, and a laboratory test was performed on an upper, weathered soil layer. The test results indicate that shear strength was lower at the soil-rock boundary than within the weathered soil layer. A representative geological section was subjected to two-dimensional slope stability analysis using a limit equilibrium method to assess whether the distribution of lithologies upon the slope influences the results of stability analysis. The results were then compared with those of three-dimensional slope stability analysis, for which input parameters can be varied according to the distribution of lithologies upon the slope. The three-dimensional analysis yielded safety factors of 1.26 under dry conditions and 0.55 under wet conditions, whereas the two-dimensional analysis yielded unstable safety factors of 0.92 and 0.32, respectively. These findings show that the results of stability analysis are affected by the distribution of different lithologies upon the slope. Given that the studied slope collapsed immediately after rainfall, it is likely that the results of the three-dimensional analysis are more reliable.

• Journal of Korean Medical classics
• /
• v.19 no.4
• /
• pp.12-26
• /
• 2006

유하간(劉河間), 주단계적학설전파이후(朱丹溪的학說전播以后), 인위명대모사의가용약적시후편중고한(因위明代某些의家用葯的時候偏重苦寒), 소이도치료상비위이극벌진양적폐두(所以도致了상脾胃而克伐眞陽的弊두). 종이위료교정착오(종而위了교正착오), 형성료주장온보적온보학파(形成了主張溫보的溫보學派). 설기(설己), 손일규(孫一圭), 張景岳等溫보학파강조주재생명적비위(張景岳等溫보學派强凋主宰生命的脾胃), 신명양기(腎命陽氣), 재변증론치방면입족우선(在辨證論治方面立足于先), 후천(後天), 중시비여신(重視脾與腎), 선용료감온적약물(善用了甘溫的藥物). 저대우교정착오기착극대적작용(저대于교正錯오起着極大的作用), 동시논증(同時논증), 이론전개상비위여신명이주제공탁료(理론展개上脾胃여腎命以主제공托了), 우기후자가심료명문학설적연구(尤其后者加深了命門학설的硏究). 장경악활동적명대시이주자학위국책적(張景岳活동的明代是以朱子學위國策的), 구비사변성적철(具비思辨性的哲) 학배영상(학背영上), 추상(推想)"리(理)"이발휘의(而발휘의) 학이론(학理론). 우시저시기의가문입족우(于是저시期의家門立足于) "황제내경(黃帝內經)" 여연기론진행료기초이론화임상연구(여연氣論진行了基초理론和임床硏究), 경악통과편찬(景岳通과編찬) "내경(內經)"이저작(而著作)"류경(類經)"등(等), 근거자기적임상실험(根据自己的임床실험), 제출료온보학설(提出了溫보학설). 타쟁론적초점시자기제출적(他爭론的焦点是自己提出的)"음부족론(음不足론)". 침대전현적쟁론상(침대前현的爭론上), 경악이하간여범계위대상경(岳以河間여凡溪위대象). "경악전서(景岳全書)" 지운(之云): "양자유하간출(襄自劉河間出), 이서화입론(以署火立論), 전용한량벌차양기(專用寒凉伐此陽氣), 기해이심(其害已甚), 뢰동원선생비위지화필수온양(賴東垣先生脾胃之火必須溫養), 연상미능진척일편지류(然尙未能盡斥一偏之謬), 이단계복출(而丹溪復出), 우입음허화동지론(又立陰虛火動之論) ...... 한량지폐우복성행(寒凉之弊又復盛行), 부선수기해자기거이불반(夫先受其害者旣去而不返), 후습이용자유미이불오(後習而用者猶迷而不悟)", 지분료하간여단계시(指분了河間여丹溪是)"헌기지마(軒岐之魔)". 저사주장현출독특적유해저(些主장현出독特的유解), 이대후대학설발전적봉헌(以대后代학설발展的奉헌). 경악침대단계적"양상유여(景岳침대丹溪的)"양상유여(陽常有餘), 음상부족(陰常不足)", "기유여변시화(氣有餘便是火)", 설성(설成)"양비유여(陽非有餘), 진양부족(眞陽不足)", "기부족변시한(氣不足便是寒)", "상화부시사화(相火不是邪火)", 대단계학설견지료비판적입장(대丹溪학설堅持了批判的立장). 단계제출(丹溪提出)"양음설(養陰說)"이수립음허화왕적병기이론(而수立陰虛火旺的病機理론), 타적(他的)'양유여음부족론(陽有餘陰不足論)'상(上), '음(陰)'주요지생식물질(主要指生殖物질), "양(陽)"지정욕(指情欲). 가시중심사상시강조생리적양생(可是中心思想是强조生理的양생), 몰수립실제(沒수立실제)'음허화왕(陰虛火旺)'적병기(的病機). 취시장경악실재완성료저사병기(就是張景岳실在完成了저些病機). 경악재(景岳在) "진음론(眞陰論)" '장형질설성진양적상(將形질설成眞陽的象), 이명문위기(以命문위其)', 용(用)"개부족(皆不足)"해석질병(解석질病), 이익화(以益火) 장수이론위치법(장水理론위治法). 이차제조좌우귀환(而且制造左右歸丸) 음이귀납료치료방법(飮以귀納了治료方法), 발휘진음(발휘眞陰), 진양학설이구조유계통적이론(眞陽學說而구造有系統的理론). 저양위의가적쟁론핵심리유상화론(저兩位의家的爭론核心里有相火論), 논자상교연구타문적이론이보고기결과(논者相교硏究他문的理론而보告其結果).

• (The)Study of the Eastern Classic
• /
• no.36
• /
• pp.403-432
• /
• 2009

In this paper, I examined two things. First explore the of the reality(眞) in poems written on paintings and discussion on paintings in men of letters of Pre-chosun dynasty, furthemore, it analyzes the meaning and thought. To explain it, I would like to analyse the discourse surrounding the reality(眞) in poems written on paintings and discussion on paintings, and concept of the borrowing(假) and the unreal(幻). First of all, I examine the ways that the view of nature of Confucians is pertinent to the abiding in reverence and the investigation of principles of confucians, also painting is necessarry condition for their moral and spiritual self-cultivation. In the discourse surrounding the reality, it is to suggest from 'natural reality (天眞)' to escape from the reality(眞), and proceeds to examine the transformation of reality(眞) in mind(人心). Furthermore I examine the meaning of transform and delicate difference between borrowing(假) and the unreal(幻). In this process, concept of the borrowing(假) and the unreal(幻) is divided into the two meaning. False(假) is to become the Borrowing and painting, the unreal(幻) is change into the act of recognition. In conclusion, I examined the significant transformation of the reality(眞) and the unreal(幻). The reality(眞) has been recognized as a important concept, it is diverged into the Nature, outer things and painting mind, and the object of ultimate value in appreciation and painting of Pre-chosun dynasty.

• The Journal of Korean Academy of Prosthodontics
• /
• v.25 no.1
• /
• pp.281-302
• /
• 1987

의치상 재료 종류에 따라 의치, 점막 및 하악골에 발생되는 변위 및 응력을 연구하기 위하여 컴퓨터를 이용한 수치적 해석인 2차원 유한 요소법을 이용하였다. 2차원 유한 요소 모형으로선 표준 크기의 하악골 및 의치를 고려하여 231개의 사변형 요소 및 268개의 절점으로 분할한 후 각 구성 성분의 물리적 성질인 탄성률 및 프와송비를 대입시켰다. 사용된 의치로서는 일반 합성수지의치, 2mm후경의 탄성재를 의치상 하부에 이장한 합성수지의치, 2mm후경의 탄성재를 치아와 의치상 중앙에 삽입한 합성수지의치 및 0.5mm후경의 금속상의치의 4종류였으며, 하중시에 하악의 고정 부위로선 생체와 동일 조건을 부여하기 위하여 교근, 내측익돌근, 측두근등의 하악 폐구근이 부착되는 하악각 부위 및 하악 근돌기 부위의 16절점을 고정점으로 하였다. 하중 조건으로선 하악 제1대구치의 일점에 10kg의 수직 집중하중, 하악 중절치의 일점에 7kg의 수직 집중하중 및 하악 제 1소구치로 부터 하악 제2대구치까지의 교합면에 10kg의 수직 분산하중을 부여하여 분석한 결과는 다음과 같다. 1. 하중이 의치 교합면위의 가해진 부위에 따라 다양한 의치 회전 및 강하 현상을 보였으며, 탄성재를 이장 및 삽입한 합성 수지 의치의 변위가 일반 합성수지의치 및 금속상 의치의 변위보다 더 컸다. 2. 주응력을 고려할때 점막 부위에는 주로 압축 응력이 작용하였으며 치조제 부위는 압축응력과 인장 응력이 함께 작용하였다. 3. 탄성재를 삽입한 합성수지의치에 최고 등가 응력이 집중되었으며 그 다음은 탄성재를 이장한 합성수지의치, 일반 합성수지의치의 순이였으며 금속상의 경우는 금속을 따라서 높은 등가 응력이 넓게 분산되었다. 4. 의치상 종류에 관계없이 동일 하중 조건하에선 점막에 나타나는 등가 응력의 크기 및 분산양태는 유사하였다. 5. 하악골에서 등가 응력은 의치지지 부위에만 국한되지 않고 넓게 분산 되었으며 의치상 종류 및 하중 조건에 관계없이 치조제 후방 및 하악연의 후방 부위에 특히 높은 등가응력이 집중되었다. 6. 하악 중절치의 일점에 수직 하중을 가한 경우가 다른 하중 조건에 비하여 지지점과의 거리차이로 인하여 하악골에 가장 높은 등가 응력을 유발하였다. 7. 의치상 재료에 따른 하악 골에 발생되는 응력의 크기 및 분산에는 큰 차이가 없으나 금속상의 경우가 교합압을 분산하는데는 효과적이었다.

• The Journal of Engineering Geology
• /
• v.21 no.4
• /
• pp.281-293
• /
• 2011

We investigated the causes and characteristics of a landslide at Hwangryeong Mountain, Busan, based on aerial photos, annual precipitation data, rock fracture patterns, and geomorphic features using GIS Software, and a statistical analysis of tilted trees. The analyzed slope shows evidence of a previous slope failure event and the possibility of future failures. Although the NW-SE trending slope was relatively stable until 1975, a large-scale slope failure occurred between 1975 and 1985 due to complex factors, including favorably oriented geologic structures, human activity, and heavy rain. This indicates that a detailed study of geologic structures, slope stability, and rainfall characteristics is important for slope cuttings that could be a major factor and cause of urban landsliding events. The statistic analysis of tilted trees shows a slow progressive creeping type of mass wasting with rock falls oblique to the dip of the slope, with the slope having moved towards the west since 1985. A concentration of tree tilting has developed on the northwestern part of the slope, which could reach critical levels in the future. The analysis of deformed trees is a useful tool for understanding landslides and for predicting and preventing future landslide events.

• Progress in Medical Physics
• /
• v.5 no.2
• /
• pp.57-68
• /
• 1994

Purpose : The purposes are to discuss the reason to measure dose distributions of circular small fields for stereotactic radiosurgery based on medical linear accelerator, finding of beam axis, and considering points on dosimetry using home-made small water phantom, and to report dosimetric results of 10MV X-ray of Clinac-18, like as TMR, OAR and field size factor required for treatment planning. Method and material : Dose-response linearity and dose-rate dependence of a p-type silicon (Si) diode, of which size and sensitivity are proper for small field dosimetry, are determined by means of measurement. Two water tanks being same in shape and size, with internal dimension, 30${\times}$30${\times}$30cm$^3$ were home-made with acrylic plates and connected by a hose. One of them a used as a water phantom and the other as a device to control depth of the Si detector in the phantom. Two orthogonal dose profiles at a specified depth were used to determine beam axis. TMR's of 4 circular cones, 10, 20, 30 and 40mm at 100cm SAD were measured, and OAR's of them were measured at 4 depths, d$\sub$max/, 6, 10, 15cm at 100cm SCD. Field size factor (FSF) defined by the ratio of D$\sub$max/ of a given cone at SAD to MU were also measured. Result : The dose-response linearity of the Si detector was almost perfect. Its sensitivity decreased with increasing dose rate but stable for high dose rate like as 100MU/min and higher even though dose out of field could be a little bit overestimated because of low dose rate. Method determining beam axis by two orthogonal profiles was simple and gave 0.05mm accuracy. Adjustment of depth of the detector in a water phantom by insertion and remove of some acryl pates under an auxiliary water tank was also simple and accurate. TMR, OAR and FSF measured by Si detector were sufficiently accurate for application to treatment planning of linac-based stereotactic radiosurgery. OAR in field was nearly independent of depth. Conclusion : The Si detector was appropriate for dosimetry of small circular fields for linac-based stereotactic radiosurgery. The beam axis could be determined by two orthogonal dose profiles. The adjustment of depth of the detector in water was possible by addition or removal of some acryl plates under the auxiliary water tank and simple. TMR, OAR and FSF were accurate enough to apply to stereotactic radiosurgery planning. OAR data at one depth are sufficient for radiosurgery planning.