• Title/Summary/Keyword: physical model investigation

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The Analgesic Effects of Transcutaneous Electrical Nerve Stimulation and Interferential Currents on the Experimental Ischemic Pain Model: Frequency 50 Hz (실험적 허혈 통증 모델에서 경피신경전기자극과 간섭파전류의 진통 효과 비교 : 주파수 50 Hz를 중심으로)

  • Bae, Young-Hyeon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.6
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    • pp.2617-2624
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    • 2012
  • Interferential currents (IFC) and transcutaneous electrical nerve stimulation (TENS) are used for pain management. This study compared the analgesic effects of IFC and TENS on experimentally induced ischemic pain in otherwise pain-free subjects using a modified version of the submaximal-effort tourniquet technique. The subjects were 14 volunteers (7 male, 7 female) without known pathology that could cause pain. Their mean age was $26.7{\pm}2.0$ years. A single-blind, sham controlled, parallel-group method was used. The primary outcome measure was the change in the self-report of pain intensity during 1 of 3 possible interventions: (1) IFC, (2) TENS, or (3) sham electrotherapy. The IFC and TENS were administered on the forearm, and the sham electrotherapy group received no current output via a dummy stimulator. The results show that a 2-way repeated-measures analysis of variance revealed that there was no change in pain intensity during treatment when all 3 groups were considered together. The mean to pain intensity with the IFC intervention was no different than with TENS. Thus, Statistical analysis showed that both interventions decreased the pain intensity ratings significantly and the difference between interventions was not simply insignificant. IFC has been shown to be more comfortable than TENS in present studies and is likely to be better accepted and tolerated by patients, clinical investigation is warranted.

Intermediate Principal Stress Dependency in Strength of Transversely Isotropic Mohr-Coulomb Rock (평면이방성 Mohr-Coulomb 암석 강도의 중간주응력 의존성)

  • Lee, Youn-Kyou
    • Tunnel and Underground Space
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    • v.23 no.5
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    • pp.383-391
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    • 2013
  • A number of true triaxial tests on rock samples have been conducted since the late 1960 and their results strongly suggest that the intermediate principal stress has a considerable effect on rock strength. Based on these experimental evidence, various 3-D rock failure criteria accounting for the effect of the intermediate principal stress have been proposed. Most of the 3-D failure criteria, however, are focused on the phenomenological description of the rock strength from the true triaxial tests, so that the associated strength parameters have little physical meaning. In order to confirm the likelihood that the intermediate principal stress dependency of rock strength is related to the presence of weak planes and their distribution to the preferred orientation, true triaxial tests are simulated with the transversely isotropic rock model. The conventional Mohr-Coulomb criterion is extended to its anisotropic version by incorporating the concept of microstructure tensor. With the anisotropic Mohr-Coulomb criterion, the critical plane approach is applied to calculate the strength of the transversely isotropic rock model and the orientation of the fracture plane. This investigation hints that the spatial distribution of microstructural planes with respect to the principal stress triad is closely related to the intermediate principal stress dependency of rock strength.

Parish Nursing : A New Challenge for Primary Health Care (지역교회간호(Parish Nursing) - 일차건강간호를 위한 새로운 도약)

  • No, Yu-Ja;Baek, Yeong-Mi
    • The Korean Nurse
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    • v.37 no.2
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    • pp.53-62
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    • 1998
  • ursing as a profession is characterized by its holistic, mind-body-spirit approach to the patient. Also, nurses have historically been the leaders in health education and promotion. Parish nursing has a great potential for providing primary preventive health care. services as well as assisting people to access the health care system. While working in the community, parish nurses see the church as the new arena for delivering health care services. The parish nurse program was introduced by Granger Westberg in 1984. The concept of parish nursing is based on several beliefs; health is multidimensional and affects all aspects of an individual-physical, psychological, social, and spiritaul being. Parish nursing is one model in which churches can cooperatively work with health care institutions to address the needs of their parishioners. The role of the parish nurse is emphasized in four basic area: a) health education, b) health counseling, c) referal services, and d) facilitation and organization of support groups within the congregation. The parish nurse programs work chiefly in congregation or commuity where a certain language of faith is ready at hand. This means that the parish nurse works in an ecology of meanings and care which encourages the drawing on the message of God's grace, the practices and habits it encourages. The parish nurse may be involved in the church's health ministries and may work on either paid or volunteer basis; however, one of the most important qualification of the parish nurse is to have the nursing knowledge and skills to practice within the standards of Nursing Practice Act. The completion of standards of practice for professional nurses practicing as parish nurses had been identified as a priority by the HMA Executive Board (1996, HMA). In conclusion, parish nursing promotes health and healing by empowering the faith community, family, or individual to incorporate health and healing practices. There are several preconditions that should proceed to establish the foundation for successful development of the parish nursing program in Korea. First, reciprocal relationship with home health nursing should be considered. Second, correct terms and concepts of parish nursing should be studied and understood. Third, systematic study and investigation should be followed for further development of parish nursing. Fourth, strengths and weaknesses of different models should be studied to develop proper model of parish nursing for Korean situation. Finally, consensus of standardized education program and corporation with various religious communities as well as health institutions should be established. When these preconditions are met, the role of parish nursing as a new program for the promotion of holistic health will be established.

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Comparative Investigation of Convective Heat Transfer Coefficients for Analyzing Compressed Hydrogen Fueling Process (압축 수소 충전 공정 해석을 위한 대류 열전달 계수 비교 분석)

  • Hyo Min Seo;Byung Heung Park
    • Journal of the Korean Institute of Gas
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    • v.27 no.3
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    • pp.123-133
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    • 2023
  • Commercial hydrogen fuel cell vehicles are charged by compressing gaseous hydrogen to high pressure and storing it in a storage tank in the vehicle. This process causes the temperature of the gas to rise, to ensure the safety to storage tanks, the temperature is limited. Therefore, a heat transfer model is needed to explain this temperature rise. The heat transfer model includes the convective heat transfer phenomenon, and accurate estimation is required. In this study, the convective heat transfer coefficient in the hydrogen fueling process was calculated and compared using various correlation equations considering physical phenomena. The hydrogen fueling process was classified into the fueling line from the dispenser to the tank inlet and the storage tank in the vehicle, and the convective heat transfer coefficients were estimated according to process parameters such as mass flow rate, diameter, temperature and pressure. As a result, in the case of the inside of the filling line, the convective heat transfer coefficient was about 1000 times larger than that of the inside of the storage tank, and in the case of the outside of the filling line, the convective heat transfer coefficient was about 3 times larger than that of the outside of the storage tank. Finally, as a result of a comprehensive analysis of convective heat transfer coefficients in each process, it was found that outside the storage tank was lowest in the entire hydrogen fueling process, thus dominated the heat transfer phenomenon.

An Influence of the Satisfaction on Factors related to Educational Services sales of Re-registration and the Word of Mouth (교육서비스 관련 상품 판매요인에 대한 교육서비스 만족이 재등록과 구전효과에 미치는 영향)

  • Kang, Gye-Young;Song, In-Am;Hwang, Hee-Joong
    • Journal of Distribution Science
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    • v.9 no.3
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    • pp.15-23
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    • 2011
  • This study examined the effects educational service elements have on the satisfaction of educational service; it also analyzed how such satisfaction influenced educational institutions' registration renewal and word-of-mouth communications about the schools. The key factors of educational services included the following four components: physical environment, education programs, instructors, and tuition fee. An investigation into how the factors of educational services in private educational institutions may affect consumer satisfaction was an additional goal of this study. Based on the cause-and-effect analysis of the above constructs, the degree of influence that each of the attributes and the component factors have on consumers' educational service selection, as well as the consumers' satisfaction, were explored. An empirical analysis was conducted on students who were taking classes in cram schools; the analysis was also conducted on the students' parents. The results indicated that the hypotheses regarding the elements of educational service, educational program, and the instructor factor were supported. Furthermore, a hypothesis concerning the effects educational service satisfaction has on re-registration and word of mouth was supported, as well. Upon aggregating the above study results, it was concluded that when determining the effects of satisfaction on educational service, the educational program, and the instructor factor played a crucial role, while physical surroundings and tuition did not. When addressing the influence of the educational services factors on educational services satisfaction, education programs and instructors had a positive effect, whereas physical environment and tuition fee had no statistically significant impact. According to the influence of educational services satisfaction on registration renewal and word-of-mouth effects, educational services satisfaction was found to be a positive influential factor for both. In addition, it was found that satisfaction of educational service had a positive effect on renewing enrollment and forming word-of-mouth recommendations. Although the research seems simple, some theoretical implications can be drawn, as follows: First, one interpretation of the findings that the programs' and instructors' factors had a positive effect on educational services satisfaction but the physical environment and tuition fee factors did not have a significant effect suggests that the greatest influence factors in educational services are educational programs and instructors. Second, increased educational services satisfaction may result in consumer behavior changing, resulting in more registration renewals and more favorable word-of-mouth comments. Third, increased educational services satisfaction may result in enhancing consumer responses, resulting in more registration renewals and more favorable word-of-mouth opinions. Further research directions should include developing an integrated model that will allow for variation over time, before and after purchases, in relation to consumers' choices of educational services.

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Investigation of Rock Slope Failures based on Physical Model Study (모형실험을 통한 암반사면의 파괴거동에 대한 연구)

  • Cho, Tae-Chin;Suk, Jae-Uk;Lee, Sung-Am;Um, Jeong-Gi
    • The Journal of Engineering Geology
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    • v.18 no.4
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    • pp.447-457
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    • 2008
  • Laboratory tests for single plane sliding were conducted using the model rock slope to investigate the cut slope deformability and failure mechanism due to combined effect of engineering characteristics such as angle of sliding plane, water force, joint roughness and infillings. Also the possibility of prediction of slope failure through displacement monitoring was explored. The joint roughness was prepared in forms of saw-tooth type having different roughness specifications. The infillings was maintained between upper and lower roughness plane from zero to 1.2 times of the amplitude of the surface projections. Water force was expressed as the percent filling of tension crack from dry (0%) to full (100%), and constantly increased from 0% at the rate of 0.5%/min and 1%/min upto failure. Total of 50 tests were performed at sliding angles of $30^{\circ}$ and $35^{\circ}$ based on different combinations of joint roughness, infilling thickness and water force increment conditions. For smooth sliding plane, it was found that the linear type of deformability exhibited irrespective of the infilling thickness and water force conditions. For sliding planes having roughness, stepping or exponential types of deformability were predominant under condition that the infilling thickness is lower or higher than asperity height, respectively. These arise from the fact that, once the infilling thickness exceeds asperities, strength and deformability of the sliding plane is controlled by the engineering characteristics of the infilling materials. The results obtained in this study clearly show that the water force at failure was found to increase with increasing joint roughness, and to decrease with increasing filling thickness. It seems possible to estimate failure time using the inverse velocity method for sliding plane having exponential type of deformability. However, it is necessary to estimate failure time by trial and error basis to predict failure of the slope accurately.

International and domestic research trends in longitudinal connectivity evaluations of aquatic ecosystems, and the applicability analysis of fish-based models (수생태계 종적 연결성 평가를 위한 국내외 연구 현황 및 어류기반 종적 연속성 평가모델 적용성 분석)

  • Kim, Ji Yoon;Kim, Jai-Gu;Bae, Dae-Yeul;Kim, Hye-Jin;Kim, Jeong-Eun;Lee, Ho-Seong;Lim, Jun-Young;An, Kwang-Guk
    • Korean Journal of Environmental Biology
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    • v.38 no.4
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    • pp.634-649
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    • 2020
  • Recently, stream longitudinal connectivity has been a topic of investigation due to the frequent disconnections and the impact of aquatic ecosystems caused by the construction of small and medium-sized weirs and various artificial structures (fishways) directly influencing the stream ecosystem health. In this study, the international and domestic research trends of the longitudinal connectivity in aquatic ecosystems were evaluated and the applicability of fish-based longitudinal connectivity models used in developed countries was analyzed. For these purposes, we analyzed the current status of research on longitudinal connectivity and structural problems, fish monitoring methodology, monitoring approaches, longitudinal disconnectivity of fish movement, and biodiversity. In addition, we analyzed the current status and some technical limitations of physical habitat suitability evaluation, ecology-based water flow, eco-hydrological modeling for fish habitat connectivity, and the s/w program development for agent-based model. Numerous references, data, and various reports were examined to identify worldwide longitudinal stream connectivity evaluation models in European and non-European countries. The international approaches to longitudinal connectivity evaluations were categorized into five phases including 1) an approach integrating fish community and artificial structure surveys (two types input variables), 2) field monitoring approaches, 3) a stream geomorphological approach, 4) an artificial structure-based DB analytical approach, and 5) other approaches. the overall evaluation of survey methodologies and applicability for longitudinal stream connectivity suggested that the ICE model (Information sur la Continuite Ecologique) and the ICF model (Index de Connectivitat Fluvial), widely used in European countries, were appropriate for the application of longitudinal connectivity evaluations in Korean streams.

Investigation and Analysis of Hazards for Cultivation Environment to Establish the Good Agricultural Practices(GAP) of Soybean (콩 GAP 모델 확립을 위한 재배환경의 위해요소 조사 및 분석)

  • Kim, Kyeong-Yeol;Song, Jeong-Eon;Heo, Rok-Won;Lee, Won-Gyeong;Nam, Min-Ji;Kim, Jeong-Sook;Shim, Won-Bo;Gil, Jung-Gwon;Jung, Chan-Sik;Park, Keum-Yong;Chung, Duck-Hwa
    • Journal of agriculture & life science
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    • v.44 no.6
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    • pp.121-132
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    • 2010
  • Soybean farms in Changnyeong were selected for hazard analysis to establish the Good Agricultural Practices (GAP) model of soybean, and physical, chemical(heavy metal) and biological(sanitary indications, foodborne pathogens) hazard analysis for cultivation environment (soil, water) was carried out. First, bow which is able to be mixed in soil and water was confirmed as physical hazard. Levels (Cd:0.01~0.103, Cu:0.001~6.036, As:0.006~3.045, Hg:ND~0.041, Pb:0.003~3.952, $Cr^{+6}$:0.007~0.496, Zn:0.001~66.500, Ni:0.003~18.010) of heavy metals in soil and water were appropriate for GAP criteria. In biological hazard, APC and coliform in soil were detected at the levels of $6.0{\pm}0.3$ and $3.6{\pm}1.6$ log CFU/g, and levels of water were $3.5{\pm}0.7$ and $1.9{\pm}0.7$ log CFU/mL, while E. coli wasn't detected in all sample. However, coliform in water wasn't appropriate for criteria, and E. coli O157 was detected about 22% in some farms, so it needs ways to prevent contamination by human and animals excrements. In conclusion, it needs proper management to prevent cross-contamination of hazards although physical and chemical hazard level were appropriate for GAP criteria while biological hazard wasn't.

Behavior of Concrete Columns Confined by Carbon Fiber Sheets under a Constant Axial Force with Reversed Cyclic Lateral Loading (일정축력하의 탄소섬유쉬트 보강기둥의 횡가력시 거동특성에 관한 실험연구)

  • Chun, Sung-Chul;Park, Hyung-Chul;Ahn, Jae-Hyen;Park, Chil-Lim
    • Magazine of the Korea Concrete Institute
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    • v.11 no.2
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    • pp.147-156
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    • 1999
  • An investigation was conducted into the flexural behavior of earthquake damaged reinforced concrete columns repaired with carbon fiber sheets. Six column specimens were tested to failure under reversed cyclic loading. Two columns were specimens for control with no sheets and tested. These columns were repaired with carbon fiber sheets and retested to evaluate the effect of the confinement of the carbon fiber on the damaged column. Another two columns were repaired and tested with no pre-cyclic loading. The test specimens were designed to model single bent under a constant axial force with reversed cyclic lateral loading. Carbon fiber sheets were used to repair damaged concrete columns in the critically stressed areas near the column footing joint and the physical, mechanical properties of carbon fiber sheets are described. The performance of repaired columns in terms of their hysteretic response is evaluated and compared to those of the original columns. The results indicate that the repaire technique with carbon fiber sheets is highly effective. Both flexural strength and displacement ductility of repaired columns were higher than those of the original columns.

FINITE ELEMENT STRESS ANALYSIS OF IMPLANT PROSTHESIS ACCORDING TO PLATFORM WIDTH OF FIXTURE (임플란트 고정체의 platform의 크기에 따른 유한요소법적 응력분석)

  • Chung Kyung-Min;Chung Chae-Heon;Jeong Seung-Mi
    • The Journal of Korean Academy of Prosthodontics
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    • v.41 no.5
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    • pp.674-688
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    • 2003
  • Statement of Problem : With increasing demand of the implant-supported prosthesis, it is advantageous to use the different platform width of the fixture according to bone quantity and quality of the patients. Purpose : The purpose of this study was to assess the loading distributing characteristics of two implant designs according to each platform width of fixture, under vertical and inclined loading using finite element analysis. Material and method : The two kinds of finite element models were designed according to each platform width of future (4.1mm restorative component x 11.5mm length, 5.0mm wide-diameter restorative component x 11.5mm length). The crown for mandibular first molar was made using UCLA abutment. Each three-dimensional finite element model was created with the physical properties of the implant and surrounding bone. This study simulated loads of 200N at the central fossa in a vertical direction, 200N at the outside point of the central fossa with resin filling into screw hole in a vertical direction and 200N at the buccal cusp in a 300 transverse direction individually Von Mises stresses were recorded and compared in the supporting bone, fixture, and abutment screw. Results : The stresses were concentrated mainly at the cortex in both vertical and oblique load ing but the stresses in the cancellous bone were low in both vertical and oblique loading. Bending moments resulting from non-axial loading of dental implants caused stress concentrations on cortical bone. The magnitude of the stress was greater with the oblique loading. Increasing the platform width of the implant fixture decreased the stress in the supporting bone, future and abutment screw. Increased the platform width of fixture decreased the stress in the crown and platform. Conclusion : Conclusively, this investigation provides evidence that the platform width of the implant fixture directly affects periimplant stress. By increasing the platform width of the implant fixture, it showed tendency to decreased the supporting bone, future and screw. But, further clinical studies are necessary to determine the ideal protocol for the successful placement of wide platform implants.