대규모 노천 석탄광산의 한계사면높이 결정과 사면파괴 예측을 위한 계측자료 해석

정용복(Yong-Bok JUNG),선우춘(Choon SUNWOO),이종범(Jong-Beom LEE) 한국암반공학회 2008 터널과지하공간 Vol.18 No.6

노천광산에서 사면설계는 안정성과 경제성 측면에서 동시에 접근하여 결정해야 한다. 또한 일반 도로나 철도 연변의 사면과는 달리 대부분 지보나 보강없이 굴착해야 하기 때문에 사면각도가 가장 중요한 설계 변수이다. 본 연구에서는 인도네시아 파시르에 위치한 노천채광방식의 대규모 석탄광산 사면에 대하여 안정성 측면에서의 사면 각도 및 한계사면높이를 결정하였으며 이러한 설계가 가지고 있는 불확실성을 보완할 수 있는 계측 및 계측자료 해석을 수행하였다. 연구 결과, 사면각도(Overall slope angle) 30°를 유지하는 경우 안전율 1.5를 확보하는 최대개발심도는 353~438 m로 계산되었으나 강도정수에 대한 민감도분석결과를 고려할 때 사면높이는 300 m를 초과하지 않는 것이 바람직하다. 또한 변위계측자료에 대한 역변위속도 분석 결과가 현장사면 사례와 잘 일치하여 이 방법을 통해 사면의 불안정성 및 파괴시기를 대략적으로 예측할 수 있을 것으로 판단된다. Open-pit mine slope design must be carried out from the economical efficiency and stability point of view. The overall slope angle is the primary design variable because of limited support or reinforce options available. In this study, the slope angle and critical slope height of large coal mine located in Pasir, Kalimantan, Indonesia were determined from safety point of view. Failure time prediction based on the monitored displacement using inverse velocity was also conducted to make up for the uncertainty of the slope design. From the study, critical slope height was calculated as 353~438 m under safety factor guideline (SF>1.5) and 30° overall slope angle but 300m is recommended as a critical slope height considering the results of sensitivity analysis of strength parameters. The results of inverse velocity analysis also showed good agreement with field slope cases. Therefore, failure of unstable slope can be roughly detected before real slope failure.

소아의 최대개구량에 관한 연구

백병주,김상훈,양연미,김재곤 大韓小兒齒科學會 2001 大韓小兒齒科學會誌 Vol.28 No.4

최근에 측두하악장애(Temporomandibular Disorder, TMD)는 해마다 증가하는 경향을 보이고 있다. 측두하악장애는 저작근, 측두하악관절 및 그와 관련된 구조물의 많은 임상증상을 포함하는 포괄적인 용어이다. 측두하악장애로 치과에 내원하는 환자는 여성이 많으며, 각 연령별 분포에서 보면 10대 후반에서 20대 후반에 호발한다. 그러나 최근에는 호발연령이 낮아지는 경향을 보이고 있다. 이에 측두하악장애의 조기진단의 필요성이 요구되어지며, 본 논문에서는 진단의 한 방법으로 간편하면서 쉽게 시행할 수 있는 최대개구량을 측정하였다. 최대개구량에 관한 여러 보고가 있지만, 소아기의 전 연령을 대상으로 광범위하게 조사된 보고는 희귀하다. 이에 저자는 4세부터 13세까지 1775명의 어린이를 대상으로 최대개구량을 측정하였으며, 최대개구량과 연련, 신장, 체중에 관한 상관관계를 조사하여 악관절장애 진단의 기초적인 참고자료로 이용하고자한다. 본 연구에서는 4세에서 13세까지의 1775명(남자943명, 여자832명)을 대상으로 최대개구량과 연령, 신장, 체중의 상관관계에 관한 비교분석을 시행하여 다음의 결론을 얻었다. 1. 4세에서 12세까지의 연령군중 4세, 8세, 12세의 평균 최대개구량을 보면 남자의 경우 각각 40.16mm, 47.32mm, 50.54mm였고, 여자의 경우 각각 39.79mm, 44.85mm, 48.09mm였다. 2. 연령이 증가함에 따라 최대개구량은 증가하는 경향을 보였고, 남자가 여자보다 큰 측정치를 보였다. 3. 신장이 증가함에 따라 최대개구량은 증가하는 경향을 보였으며, 105cm 이상 115cm 미만을 제외하고는 남자가 여자보다 큰 측정치를 보였다. 4. 체중이 증가함에 따라 최대개구량은 증가되는 경향을 보였으며, 모든 군에서 남자가 여자보다 큰 측정치를 보였다. 5. 최대개구량과 연령, 신장, 체중간의 관계에서 유의한 순상관 관계를 보였으며, 신장이 가장 높은 상관성을 보였다. Recently, tempormandibular disorder(TMD) shows an tendency to increase every year. TMD is a collective term embracing a number of clinical problems that involve the masticatory musculature, temporomandibular joint(TMJ) and associated structures, or both. TMD, viewed in distribution of age, often occurred from late teens to late twenties. But recently, the age of occurrence tends to be lower. Accordingly, early diagnosis of tempormandibular disorder is very important. In this study, we measured the maximum mouth opening which is simple and easy to carry out as a way of TMD diagnosis. In this study, the maximum mouth opening was examined for 1,775 children from 4 to 12 years of age. We compared the relationship between the maximum mouth opening with the age, height, and weight. The results obtained were summarized as follows; 1. The mean maximum mouth openings of 4, 8, and 12 year of age were respectively 40.16mm, 47.32mm, 50.54mm for male, 39.79mm, 44.85mm, 48.09mm for female. 2. The maximum mouth opening increased with age, and the values were greater in male than in female. 3. The maximum mouth opening increased wit height, and the values were greater in male than in female except between 105cm and 115cm. 4. The maximum mouth opening increased with weight, and the values were greater in male than in female. 5. The correlation between the maximum mouth opeing with the age, height, and weight was all significant and height showed the highest correlation.

압하율에 따른 기공압착 거동에 관한 실험적 연구

최익준(I. J. Choi),최호준(H. J. Choi),박훈재(H. J. Park),최석우(S. Choi),정택우(T. W. Jung),박동규(D. K. Park),최성규(S. K. Choi),임성주(S. J. Lim) 한국소성가공학회 2009 한국소성가공학회 학술대회 논문집 Vol.2009 No.5

In this work, closing behavior of the voids generated in a casting process was investigated for various parameters such as reductions in height, void size and billet rotation during hot open die forging process. The reduction in height and path schedule including the number of paths and billet rotation were chosen as key process variables to express the change of geometrical void shape and void closing behavior. On the other hand, values of die overlapping and die width ratio were set to be constant. Extend of void closure was observed and evaluated using tensile test and microscope. Based on the experimental result, it is ensured that void closure do not occur at 15% and 30% reduction in height as well as one or two rotations of a billet. The useful datum obtained from this study could be utilized to establish an optimum path schedule in the open die forging process.

수평 개구부가 설치된 구획실의 높이가 화재 현상에 미치는 영향

김윤영,이치영 한국화재소방학회 2023 한국화재소방학회 학술대회 논문집 Vol.2023 No.2

배수갑문 테인터 게이트(Tainter Gate)의 진동현상에 관한 모형실험(Ⅱ)- 문비 안에서 밖으로의 흐름 -

이성행,우상익,Lee , Seong-Haeng,Woo , Sang-Ik 한국농공학회 2004 한국농공학회논문집 Vol.46 No.2

A model test is carried out to investigate flow-induced vibration of a Tainter gate in estuary sulices. The gate model scaled with the ratio of 1:25 is made of acryl panel dimensioned 0.66 m in width, 0.5 m in height in the concrete test flume. Firstly, natural frequencies of the model gate are measured and the results are compared with the numerical results in order to verify the model. In the flow from the gate inside to the gate outside, the amplitudes of the vibration are measured under the different gate opening and downstream water level conditions. Also revised gate models with 20 mm bottom width are tested under the different gate openings and water levels. The results are analyzed to study the characteristics of the Tainter gate vibration in the sea ward flow. These test results are assessed in comparison with the results in the lake ward flow, as a result, presents the dynamic characteristics of the Tainter gate and a basic data for the guide manuals of gate management.

트러스형 리프트 게이트의 진동현상에 관한 모형실험

이성행,김하집,박영진,함형길,공보성,Lee, Seong-Haeng,Kim, Ha-Jip,Park, Young-Jin,Hahm, Hyung-Gil,Kong, Bo-Sung 한국농공학회 2011 한국농공학회논문집 Vol.53 No.3

A model test is carried out to investigate the vibration of truss type lift gate in the four major rivers project. The gate model scaled with the ratio of 1 : 25 is made of acryl panel dimensioned 1.6 m in width, 0.28 m in height in the concrete test flume. Firstly natural frequencies of the model gate are measured and the results are compared with the numerical results in order to verify the model. The amplitudes of the vibration are measured under the different gate opening and water level conditions. The results are analyzed to study the characteristics of the gate vibration according to the small gate opening, the large gate opening and the overflow conditions. These test results presents a basic data for the guide manuals of gate management and a design method to reduce the gate vibration of truss type lift gate. Finally, the vibration of truss type lift gate are assessed in comparison with those of formerly tainter gate.

평면트러스로 지지된 리프트 게이트의 진동특성

이성행,양동운,함형길,공보성,신동욱,Lee, Seong-Haeng,Yang, Dong-Woon,Hahm, Hyung-Gil,Kong, Bo-Sung,Shin, Dong-Wook 한국농공학회 2012 한국농공학회논문집 Vol.54 No.3

Dynamic characteristic of lift gate supported by plane truss is studied by a model test scaled with the ratio of 1 : 31.25 in the four major rivers project. The vibrations of gate supported by the plane truss is assessed in comparison with those of gate supported by the space truss which was tested formerly. The gate model is made of acryl panel and calibrated by lead. A model test is conducted under the different gate opening and upstream water levels conditions in the concrete test flume dimensioned 1.6 m in width, 0.8 m in height and 24 m in length. In order to verify the model, natural frequencies of the model gate are measured, and compared with the numerical results. The vibrations of gate model supported by the plane truss in opening height of 1.0 cm~2.0 cm shows greater than one supported by the space truss. It is found that the gate model supported by the plane truss is less desirable than one supported by the space truss. thus, the latter type of gate model is requested to design.

배수갑문 테인터 게이트(Tainter Gate)의 진동현상에 관한 모형실험(Ⅰ) - 문비 밖에서 안으로의 흐름 -

이성행 ( Lee Seong Haeng ) 한국농공학회 2004 한국농공학회논문집 Vol.46 No.1

A model test is carried out to investigate flow-induced vibration of a Tainter gate in estuary sulices. The gate model scaled with the ratio of 1:25 is made of acryl panel dimensioned 0.66m in width, 0.5m in height in the concrete test flume. Firstly, natural frequencies of the model gate are measured and the results are compared with the numerical results in order to verify the model. The amplitudes of the vibration are measured under the different gate opening and water level conditions in flow from the gate outside to the gate inside. Also 5 revised gate models with bottom width increased 0.5 cm each are tested under the different gate opening and water level. The results are analyzed to study the characteristics of the gate vibration. These test results are assessed in comparison with formerly test results, as a result, presents a design method of Tainter gate to reduce the gate vibration and a basic data for the guide manuals of gate management.

모형실험에 의한 트러스형 리프트 게이트의 진동 특성

이성행(Lee, Seong Haeng),신동욱(Shin, Dong Wook),김경남(Kim, Kyoung Nam),정경섭(Jung, Kyoung Sup) 대한토목학회 2012 대한토목학회논문집 A Vol.32 No.6A

본 연구에서는 4대강 사업으로 건설중인 트러스형 리프트의 진동특성을 검토하기 위하여 모형실험이 수행된다. 경간 40 m, 높이 9 m의 트러스형 리프트게이트를 축척 1/25로 모형이론에 따라 아크릴과 납으로 모형을 제작하고, 폭 1.6 m, 길이 25 m, 높이 0.8 m의 수로에서 실험된다. 먼저 모형의 고유진동수가 측정되고 모형을 검증하기 위하여 유한요소 해석결과와 비교된다. 검증된 모형에서 상하류 수위와 문비 개방고에 따른 진동기속도 진폭이 측정된다. 또한 문비의 진동을 줄 일수 있는 하부형상을 검토하기 위하여 문비 최하부의 각도가 20°, 35°, 50°인 모형을 제작하고 실험결과를 서로 비교한다. 실험 결과는 수문 조작 시 유지관리지침의 기본 자료를 제공하고, 수문의 진동특성과 진동을 줄일 수 있는 수문의 하부형상을 검토한다. A model test is performed to investigate the dynamic behavior of truss type lift gate which is being constructed by the four major rivers project. The gate dimensioned 40 m in width, 9m in height is scaled with the ratio of 1:25 and is made of acryl panel and supplemented weight by lead in the concrete test flume dimensioned 1.2 m in width, 0.5 m in height and 30m in length. Firstly natural frequencies of the model gate are measured and compared with the numerical results for the calibration. The amplitudes of the vibration are measured under the different gate opening, upstream water level conditions. Also models with bottom angle 20°, 35° and 50° are tested and compared to find out a proper shape of bottom structure which minimizes the gate vibration. These test results presents a basic data for the guide manuals of gate management and a design method to reduce the gate vibration of truss type lift gate.

Pathogenicity and Viral Distribution of Wild Type Porcine Epidemic Diarrhea Virus and Its Cell Culture Adapted Porcine Epidemic Diarrhea Virus

Hee-Jin Ham 대한미생물학회 2022 Journal of Bacteriology and Virology Vol.52 No.3

Swine enteritis in all ages is caused by porcine epidemic diarrhea virus (PEDV), transmissible gastroenteritis virus (TGE), rotavirus, Eimeria spp. etc., and is often fatal among neonatal piglets. This study aimed to compare the pathogenicity and nucleotide sequence of ORF3 between wild-type porcine epidemic diarrhea virus (wt-PEDV) and cell culture-adapted PEDV (ca-PEDV). A total of 30 colostrum- deprived piglets that were 1 day old were inoculated with either wt-PEDV or ca-PEDV to compare the villus height and crypt depth (VH/CD) ratio, amount of viral nucleic acid in jejunum, and open reading frame (ORF) 3 nucleotide sequence via immunofluorescence labeling of viral antigen and western blot analysis. Mean jejunal villus height and crypt depth (VH/CD) ratio in piglets infected orally with Korean strain of PEDV were 6.8 ± 0.8, 7.0 ± 0.8, 8.2 ± 1.0, 8.0 ± 1.3, and 7.9 ± 1.1 in uninfected control piglets; 7.2 ± 1.2, 5.2 ± 1.4, 2.7 ± 0.3, 1.4 ± 0.2, and 1.5 ± 0.1 in wt-PEDV-infected piglets; and 7.6 ± 1.8, 3.2 ± 0.4, 2.2 ± 0.3, 1.3 ± 0.3, and 1.1 ± 0.2 in ca-PEDV-infected piglets at 12, 24, 36, 48, and 60 h post inoculation. Conclusively, the mean VH/CD ratio for wt-PEDV piglets was significantly different from that of ca-PEDV piglets at 24, 36, and 60 h post inoculation. The in situ hybridization (ISH) positive results in piglets orally infected with the Korean strain of PEDV in jejunal villus were 4.0 ± 0.8, 10.3 ± 0.5, 7.3 ± 0.5, 7.0 ± 0.8, and 5.3 ± 0.5 in ca-PEDV-infected piglets; and 4.3 ± 0.9, 16.7 ± 1.2, 9.3 ± 0.5, 9.0 ± 0.8, and 5.7 ± 0.9 in wt-PEDV-infected piglets. Conclusively, a significant difference was observed in each group. A greater amount of PEDV nucleic acid was detected in the jejunal tissues (P < 0.05) of the ca-PEDV-inoculated piglets than in those of the wt-PEDV-infected piglets at 24, 36, and 60 h post-inoculation. The nucleotide sequences of wt-PEDV and ca-PEDV were nearly identical (98.7% homology); nucleotide substitutions were noted in ORF3 that caused some amino acid changes. Statistically significant differences were observed in the pathogenicity of ca-PEDV compared with its parental wt-PEDV; ORF3 nucleotide changes were identified in ca-PEDV that possibly influenced PEDV pathogenicity