• 제목/요약/키워드: Phases-difference

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한반도의 폭파자료에 대한 2-D 수치 모델링 연구 (2-D Forward Modeling on an Explosion Data in Korea)

  • 강익범;조광현
    • 한국방재학회:학술대회논문집
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    • 한국방재학회 2007년도 정기총회 및 학술발표대회
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    • pp.137-139
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    • 2007
  • 한반도의 지각에 대한 지진파의 파형들을 피킹하기 위하여 한반도의 남동부지역에서 시행된 폭파로부터 각 관측소에서 관측된 지진자료를 2 차원 수치 순산모델링으로 계산된 이론적인 신호와 비교하였다. 실제 지진자료와 같은 완전한 파형을 얻기 위해서는 실체파뿐만 아니라 표면파를 포함한 모든 파형을 이론적으로 생성하여야 한다. 또한, 각 파형의 Q 값을 고려하여 그 감쇄 정도를 파악하여야 실제 파형과 똑 같은 이론적인 파형을 만들 수 있다. 본 연구에서는 FEM(Finite Element Method)과 FDM(Finite Difference Method) 같은 전형적인 수치 모델링 기법 대신에 수도스펙트럼기법(pseudo-spectral method)을 사용하여 이론적인 파형을 계산하였다. Q 값을 고려하지 않았기 때문에 완전한 파형을 얻기에는 어려움이 있었다. 그러나 각 관측소에 도달하는 실체파의 초기 파형들의 주시를 실제 파형과 맞추었다는 데에 그 성과가 있다고 할 수 있다. 본 연구의 궁극적인 목표는 수치 모델링을 통하여 지진원의 위치와 종류를 밝혀 내는데 그 정확성을 높이는 것이다.

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연결방법에 따른 주조체 변위에 관한 3차원적 비교연구 (THREE-DIMENSIONAL COMPARISON OF FRAMEWORK DISPLACEMENTS JOINED BY VARIOUS CONNECTION TECHNIQUES)

  • 임장섭;전영찬;정창모
    • 대한치과보철학회지
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    • 제37권3호
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    • pp.358-374
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    • 1999
  • This study measured the relative displacements of the five-unit fixed partial dentures as cast with the same fixed partial dentures sectioned and assembled by investment-soldering, solder-ing stand-soldering, and cast-joining techniques A total of fifteen specimens using a type IV gold alloy were one-piece cast as control and then sectioned and assembled five test specimens for each method were prepared. A computerized three dimensional coordinate measuring machine and specially designed cylinder for this study were used. Displacement was defined by six displacement variables for the each of cylinders incorporated in each casting: three component displacements(${\Delta}Lx,\;{\Delta}Ly,\;and\;{\Delta}Lz$) and rotational displacements(${\Delta}{\theta}x,\;{\Delta}{\theta}y,\;{\Delta}{\theta}z$). The global displacement was computed using the mathematical formula ${\Delta}R$ = Global displacement =$\sqrt{{(x'-x)}^2+{(y'-y)}^2+{(z'-z)}^2}$ Under the conditions of this study, the following conclusions were drawn: 1. The investment-soldering group showed the largest mean value of final global displacements, followed by stand-soldering group, cast-joining group and one-piece cast group. However, between the mean values of final global displacement for the cast-joining group and one-piece cast group, there was no significant difference. 2. For investment-soldering and stand-soldering groups, the greater global displacements were recorded in soldering phase than in indexing or investing phase. 3. For one-piece cast group, the displacements occured mostly in the casting phase. And for cast-joining group, there was no significant difference in global displacements among the fabricating procedures. 4. Intercentroidal distance decreased in framework-patterning, solder-indexing, solder-standing, and soldering phases, but increased in investment block-investing and casting phases. 5 Specially designed cylinder for touch-trigger type coordinate measuring machine was validated.

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항공기내 연료 및 오일온도 변화에 대한 수치해석적 연구 (A Numerical Analysis on Transient Temperatures of Fuel and Oil in a Military Aircraft)

  • 김영준;김창녕;김철인
    • 대한기계학회논문집B
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    • 제26권8호
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    • pp.1153-1163
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    • 2002
  • A transient analysis on temperatures of fuel and oil in hydraulic and lubrication systems in an aircraft was studied using the finite difference method. Numerical calculation was performed by an explicit method with modified Dufort-Frankel scheme. Among various missions, air superiority mission was considered as a mission model with 20% hot day ambient condition in subsonic region. The ambience of the aircraft was assumed as turbulent flow. Convective heat transfer coefficient were used in calculating heat transfer between the aircraft surface and the ambience. For an aircraft on the ground, an empirical equation represented as a function of free-stream air velocity was used. And the heat transfer coefficient for flat plate turbulent flow suggested by Eckert was employed for in-flight phases. The governing equations used in this analysis are the mass and energy conservation equations on fuel and oils. Here, analysis of fuel and oil temperature in the engine was not carried out. As a result of this analysis, the ground operation phase has shown the highest temperature and the largest rate of temperature increase among overall mission phases. Also, it is shown that fuel flow rate through fuel/oil heat exchanger plays an important role in temperature change of fuel and oil. This analysis could be an important part of studies to ensure thermal stability of the aircraft and can be applicable to thermal design of the aircraft fuel system.

달리기 시 인솔의 굽힘 강성 증가에 따른 발목과 중족골 관절의 운동학적 변인 및 관절 협응에 미치는 영향 (The Effects on Kinematics and Joint Coordination of Ankle and MTP Joint as Bending Stiffness Increase of Shoes during Running)

  • Kim, Sungmin;Moon, Jeheon
    • 한국운동역학회지
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    • 제31권3호
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    • pp.205-213
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    • 2021
  • Objective: The aim of this study was to analyze body stability Joint coordination pattern though as bending stiffness of shoes during stance phase of running. Method: 47 male subjects (Age: 26.33 ± 2.11 years, Height: 177.32 ± 4.31 cm, Weight: 65.8 ± 3.87 kg) participated in this study. All subjects tested wearing the same type of running shoes by classifying bending stiffness (A shoes: 3.2~4.1 N, B shoes: 9.25~10.53 N, C shoes: 20.22~21.59 N). They ran 10 m at 3.3 m/s (SD ±3%) speed, and the speed was monitored by installing a speedometer at 3 m intervals between force plate, and the measured data were analyzed five times. During running, ankle joint, MTP joint, coupling angle, inclination angle (anterior-posterior, medial-lateral) was collected and analyzed. Vector coding methods were used to calculate vector angle of 2 joint couples during running: MTP-Ankle joint frontal plane. All analyses were performed with SPSS 21.0 and for repeated measured ANOVA and Post-hoc was Bonferroni. Results: Results indicated that there was an interaction between three shoes and phases for MTP (Metatarsalphalangeal) joint angle (p = .045), the phases in the three shoes showed difference with heel strike~impact peak (p1) (p = .000), impact peak~active peak (p2) (p = .002), from active peak to half the distance to take-off until take-off (p4) (p = .032) except for active peak~from active peak to half the distance to take-off (p3) (p = .155). ML IA (medial-lateral inclination angle) for C shoes was increased than other shoes. The coupling angle of ankle angle and MTP joint showed that there was significantly difference of p2 (p = .005), p4 (p = .045), and the characteristics of C shoes were that single-joint pattern (ankle-phase, MTP-phase) was shown in each phase. Conclusion: In conclusion, by wearing high bending stiffness shoes, their body instability was increased during running.

오유혈(五兪穴)을 이용한 사시자법(四時刺法) -영추(靈樞)와 난경(難經)을 중심으로- (Study on Acupuncture Follow the Four Season)

  • 홍원식;엄동명
    • Journal of Acupuncture Research
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    • 제17권4호
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    • pp.18-27
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    • 2000
  • There is a acupuncture method which make a difference according to the four seasons, according to body region or depth in skin. We call it Acupuncture follow the four seasons(四時刺法). In several chapters of Huangdineijing(黃帝內經) introduced Acupuncture follow the four seasons. Acupuncture follow the four seasons has two kinds of acupuncture method that is to acupuncture at body region and to acupuncture at five Su points(五兪穴). To use five Su points(五兪穴) according to Yongchu(靈樞) disagree with Nanjing(難經). In Yongchu(靈樞), the five phases property disagree with five Su points(五兪穴), but in Nanjing(難經) the five phases property agree with five Su points(五兪穴). Even if we can acupuncture the same point, there will be the different effect according as what is the purpose of doing acupuncture, and when we do acupuncture. That is to say, we can use apucupuncture for the purpose of prevention in Yongchu(靈樞), and for the purpose of healing the disease in Nanjing(難經). Therefore, because we select the point on the base of meridian Kis origin which spring out, we have to acupuncture Chong point(井穴) in winter according to Yongchu(靈樞). Because we select the point on the base of meridian Kis origin which flowing, we have to acupuncture Chong point(井穴) in spring according to Nanjing(難經). And in the base of five phases' property, the purpose of selecting five Su points(五兪穴) is the prevention according to Yongchu(靈樞), and the healing according to Nanjing(難經). So even though we acupuncture the exactly same Chong point(井穴), we can expect the effect that acupuncture method supply Ki for liver in winter. and the effect that it extract pathogenic Ki(邪氣) from the liver in spring.

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돼지에서 발정 주기 동안 자궁액 내의 단백질 패턴의 변화 (Change of Protein Patterns in Uterine Fluid during Estrus Cycle in Pigs)

  • 이연주;송은지;이상희;정희태;양부근;박춘근
    • Reproductive and Developmental Biology
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    • 제37권3호
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    • pp.103-108
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    • 2013
  • An uterus is female reproductive tract organ that affected estrus cycle. During a various changes occur at uterus in estrus cycle, one of them is body fluids secretion be called uterine fluid. Therefore, the objective of this study was to investigate the changes of protein patterns using two-dimensional gel electrophoresis in uterus fluids during the follicular and luteal phases in estrus cycle of pigs. In changes of protein spots were confirmed during the follicular and luteal phases. The 136 spots were expressed in follicular phase, the 57 spots of them showed reproducibility. On the other hand, the 140 spots were expressed in luteal phase, the 73 spots of them showed reproducibility. Also, spots expressed in follicular phase were number 69 and 94 spots and spots expressed in luteal phase only were number 156, 157, 184~187, 190 and 191 spots. The spots which of higher expression levels in the luteal phase than in follicular phase were number 76 and 79 spots. In conclusion, the spots expressed in follicular and luteal phases were confirmed with difference levels and these differences are function of RNA resolving, protein synthesis and cytoskeletal architecture.

6-[4-(4'-(니트로페닐아조)펜옥시카보닐)]펜타노화 다당류들의 합성과 열방성 액정 거동 (Synthesis and Thermotropic Liquid Crystalline Behaviors of 6-[4-(4'-(nitrophenylazo) phenoxycarbonyl)] pentanoated Polysaccharides)

  • 정승용;마영대
    • 폴리머
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    • 제31권1호
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    • pp.37-46
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    • 2007
  • 셀룰로오스 아밀로오스 키토산, 키틴, 알긴산, 풀루란 또는 아밀로펙틴을 6- [4- (4'- (니트로페닐아조)펜옥시)]펜타노일 클로라이드(NA6C)와 반응시켜 전치환 또는 거의 전치환 6- [4- (4'- (니트로페닐아조)펜옥시카보닐)] 펜타노화 다당류 유도체들을 합성함과 동시에 이들의 열방성 액정의 거동들을 검토하였다. NA6C의 경우와 같이, 모든 다당류 유도체들은 단방성 네마틱 상들을 형성하였다. 이러한 사실은 다당류 유도체들의 액정 구조는 다당류 골격에 의해 결정되는 것이 아니고 mesogenic 곁사슬 그룹들에 의해 결정됨을 시사한다. 이것이 셀룰로오스 유도체들을 제외한 다당류 유도체들이 열방성 네마틱 상을 형성한다고 하는 최초의 보고이다. 다당류 유도체들에 있어서 관찰되는 네마틱 상들의 열적 안정성과 질서도는 아조벤젠 그룹들을 유연한 스페이서를 통하여 유연한 혹은 강직한 골격들에 도입시켜 얻은 고분자들에 대해 보고된 결과들과 현저히 다르다. 이들의 결과를 주사슬과 곁사슬의 배열 그리고 주사슬의 유연성의 차이와 관련하에서 검토하였다.

펜싱 팡트 동작 숙련도에 따른 세 그룹간의 운동학적 비교분석 (Kinematic Analysis between Three Groups according to Proficiency in Fencer's Fente Movement)

  • Jo, Hyun Dai;Park, Ho Yeol
    • 한국운동역학회지
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    • 제30권1호
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    • pp.51-61
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    • 2020
  • Objective: The purpose of this study is to analyse and comparison the differences of kinematic variables for Fente skill in Fencing. Method: For this, 15 people were selected as 5 beginners with less than 2 years of experience, 5 intermediate-class people with more than 2 years and less than 4 years, and 5 experts-class people with more than 4 years. Through the comparison of Marche Fente motion according to proficiency, for the necessary time, travel distance, the kinematical factor of joint angle, oneway ANOVA was performed in order to identify differences according to variables by phase. Results: The time required for each phase was shown to be shorter for all phases experts than for beginners and intermediates. At the horizontal displacement of the foot, the right foot left out the last phase and the experts appeared long. The left foot showed short beginners in all phases. The angle of forward lean showed that the angle of forward lean was tilted forward by the experts of all phases. There was a difference between the left and right joint angles of the lower limb, both of the ankle, knee and hip joints. Conclusion: In overall, Beginners should quickly widen the distance of their feet when they make a Fente movement. The beginner shall tilt the upper body forward in order to increase the angle of forward lean. The beginner shall, in the last phase, have a smaller angle on the hip joint.

돈분의 2단계 혐기발효시 산생성 단계에서의 유기물 부하율과 체류시간에 따른 휘발성지방산의 생산량 (Effect of Organic Loading Rate and Hydralic Retention Time on the Volatile Fatty Acid Production in 2- Step Anaerobic Fermentation System of Swine Wastes)

  • 김범석;이상락;맹원재
    • 한국축산시설환경학회지
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    • 제4권2호
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    • pp.167-174
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    • 1998
  • It is known that the anaerobic fermentation of organic matter (OM) is divided into 2 phases, acidogenic phase in which OM is digested into volatile fatty acid (VFA), and methanogenic phase where the produced VFA is converted to CH4 and CO2. In a natural fermenting procedure, these 2 phases occur at the same time. However the total production of end products (methane) may be limited if these 2 phases occur at the same time. This is believed to be due to the difference in growth rate, substrate-utilizing efficiency and favorable environment for each microbes (acidogens and methanogens), involved in each phase. It is therefore suggested for the maximum recycling of organic waste (such as animal waste) through providing 2 different steps in fermenting procedure, acidogenic phase and methanogenic phase, in each case the activity of involved microbes can be maintained at the maximum level. The results obtained from these experiments are summarized as follows : The loading rates of swine waste were made through 2.5, 5 and 10 gVS / l / d to identify its acidogenic fermenting character in this study. The VFA yield was maximized at 10 gVS / l / d of loading rate. On the basis of this study was executed to identify the optimum HRT of 1, 2 and 4 days at 10 gVS / l / d of loading rate in acidogenic phase. The maximum VFA yield was obtained at 1 days of HRT.

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아공정, 공정, 과공정 조성의 Al-Cu 주조합금에서의 Y2O3 분말의 분산 거동에 대한 연구 (An Investigation of Dispersion Behavior of Y2O3 Ceramic Particles in Hypo, Eutectic and Hyper Binary Al-Cu Cast Alloys)

  • 박진주;김광호;홍성모;이상훈;이민구;이창규
    • 한국분말재료학회지
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    • 제14권2호
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    • pp.123-126
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    • 2007
  • In this work, the dispersion behavior of $Y_2O_3$ particles in binary aluminum (Al)-copper (Cu) cast alloy was investigated with respect to Cu contents of 20 (hypoeutertic), 33 (eutectic) and 40 (hypereutectic) wt.%. In cases of hypo and hypereutectic compositions, SEM images revealed that the primary Al and ${\theta}$ phases were grown up at the beginning, respectively, and thereafter the eutectic phase was solidified. In addition, it was found that some of $Y_2O_3$ particles can be dispersed into the primary Al phase, but none of them are is observed inside the primary 6 phase. This different dispersion behavior of $Y_2O_3$ particles is probably due to the difference in the val- ues of specific gravity between $Y_2O_3$ particles and primary phases. At eutectic composition, $Y_2O_3$ particles were well dispersed in the matrix since there is few primary phases acting as an impediment site for particle dispersion during solidification. Based on the experimental results, it is concluded that $Y_2O_3$ particles are mostly dispersed into the eutectic phase in binary Al-Cu alloy system.