• 제목/요약/키워드: S-N fatigue

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인터넷 상에서 사용되는 미병의 개념 및 사용자 분석 - 네이버 지식-iN과 카페를 중심으로 - (Analysis of the Mibyeong Concept and User on the internet. - Focusing on Naver Jisik-iN Q&A, Cafe posts -)

  • 김선민;이시우;문수정
    • 대한예방한의학회지
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    • 제21권1호
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    • pp.95-106
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    • 2017
  • Objectives : Although interest in preventive medicine has increased recently, "Mibyeong", the preventive concept of Korean medicine, is still unfamiliar to the general public. Therefore, this study aims to investigate the concept of Mibyeong and users used on the Internet. Methods : Naver (www.naver.com), which has the highest ranking in terms of market share, number of visitors, search time share, and community category share, has been selected as a search target and jisik-iN Q&A and posts of cafe about Mibyeong were searched for recently approximately 6 years. Results : 105 cases of Jisik-iN Q&A and 283 cases of cafe posts were searched. Overall, the number of Jisik-iN Q&A and cafe posts's Mibyeong term usage was the highest in 2013. In the Internet user category, Mibyeong Term was used most commonly in the Jisik-iN Q&A by Korean medicine related medical personnel (29 cases, 28%) and in the cafe other health-related workers (87cases, 31%). In Mibyeong related cafe classification, Information Exchange (220 cases, 77%) was the most frequent and besides 39 cases (14%) used in Operation of Medical Institutions. And the concept of Mibyeong was often used as symptom-based rather than diagnostic test or disease (Cafe posts 52%, Jisik-iN Q&A 70%), in particular, topic of Mibyeong related Jisik-iN Q&A was used in the order of pain (31 cases, 16%), cancer (17 cases, 9%), fatigue (11 cases, 6%). Conclusions : This study has significance as basic research data of general Internet user group and can be used as fundamental data for awareness promotion, publicity and necessity of Mibyeong.

Changes In Mechanical Strength of Compression HIP Screws in Relation to Design Variations - A Biomechanical Analysis

  • Moon S. J.;Lee H. S.;Jun S. C.;Jung T. G.;Ahn S. Y.;Lee H.;Lee S. J.
    • 대한의용생체공학회:의공학회지
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    • 제26권2호
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    • pp.123-127
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    • 2005
  • Compression Hip Screw (CHS) is one of the most widely-used prostheses for the treatment of intertrochanteric fractures because of its strong fixation capability. Fractures at the neck and screw holes are frequently noted as some of its clinical drawbacks, which warrant more in-depth biomechanical analysis on its design variables. The purpose of this study was to evaluate changes in the strength with respect to the changes in design such as the plate thickness and the number of screw holes. Both mechanical test and FEM analysis were used to systematically investigate the sensitivities of the above-mentioned design variables. For the first part of the mechanical test, CHS (n=20) were tested until failure. The CHS specimens were classified into four groups: Group Ⅰ was the control group with the neck thickness of 6-㎜ and 5 screw holes on the side plate, Group Ⅱ 6-㎜ thick and 8 holes, Group Ⅲ 7.5-㎜ thick and 5 holes, and Group Ⅳ 7.5-㎜ thick and 8 holes. Then, the fatigue test was done for each group by imparting 50% and 75% of the failure loads for one million cycles. For the FEM analysis, FE models were made for each group. Appropriate loading and boundary conditions were applied based on the failure test results. Stresses were assessed. Mechanical test results indicated that the failure strength increased dramatically by 80% with thicker plate. However, the strength remained unchanged or decreased slightly despite the increase in number of holes. These results indicated the higher sensitivity of plate thickness to the implant strength. No fatigue failures were observed which suggested the implant could withstand at least one million cycles of fatigue load regardless of the design changes. Our FEM results also supported the above results by showing a similar trend in stress as those of mechanical test. In summary, our biomechanical results were able to show that plate thickness could be a more important variable in design for reinforcing the strength of CHS than the number of screw holes.

Feature Based Techniques for a Driver's Distraction Detection using Supervised Learning Algorithms based on Fixed Monocular Video Camera

  • Ali, Syed Farooq;Hassan, Malik Tahir
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제12권8호
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    • pp.3820-3841
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    • 2018
  • Most of the accidents occur due to drowsiness while driving, avoiding road signs and due to driver's distraction. Driver's distraction depends on various factors which include talking with passengers while driving, mood disorder, nervousness, anger, over-excitement, anxiety, loud music, illness, fatigue and different driver's head rotations due to change in yaw, pitch and roll angle. The contribution of this paper is two-fold. Firstly, a data set is generated for conducting different experiments on driver's distraction. Secondly, novel approaches are presented that use features based on facial points; especially the features computed using motion vectors and interpolation to detect a special type of driver's distraction, i.e., driver's head rotation due to change in yaw angle. These facial points are detected by Active Shape Model (ASM) and Boosted Regression with Markov Networks (BoRMaN). Various types of classifiers are trained and tested on different frames to decide about a driver's distraction. These approaches are also scale invariant. The results show that the approach that uses the novel ideas of motion vectors and interpolation outperforms other approaches in detection of driver's head rotation. We are able to achieve a percentage accuracy of 98.45 using Neural Network.

Solution for a semi-infinite plate with radial crack and radial crack emanating from circular hole under bi-axial loading by body force method

  • Manjunath, B.S.;Ramakrishna, D.S.
    • Interaction and multiscale mechanics
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    • 제2권2호
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    • pp.177-187
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    • 2009
  • Machine or structural members subjected to fatigue loading will have a crack initiated during early part of their life. Therefore analysis of members with cracks and other discontinuities is very important. Finite element method has enjoyed widespread use in engineering, but it is not convenient for crack problems as the region very close to crack tip is to be discretized with very fine mesh. However, as the body force method (BFM), requires only the boundary of the discontinuity (crack or hole) to be discretized it is easy versatile technique to analyze such problems. In the present work fundamental solution for concentrated load x + iy acting in the semi-infinite plate at an arbitrary point $z_0=x_0+iy_0$ is considered. These fundamental solutions are in complex form ${\phi}(z)$ and ${\psi}(z)$ (England 1971). These potentials are known as Melan potentials (Ramakrishna 1994). A crack in the semi-infinite plate as shown in Fig. 1 is considered. This crack is divided into number of divisions. By applying pair of body forces on a division, the resultant forces on the remaining 'N'divisions are to be found for which ${\phi}_1(z)$ and ${\psi}_1(z)$ are derived. Body force method is applied to calculate stress intensity factor for crack in semi-infinite plate. Also for the case of crack emanating from circular hole in semi-infinite plate radial stress, hoop stress and shear stress are calculated around the hole and crack. Convergent results are obtained by body force method. These results are compared with FEM results.

남자 대학 태권도 겨루기 선수의 8주간 고강도 동계 훈련 시 L-아르기닌 섭취가 경기수행능력, 젖산, 젖산탈수소효소 및 암모니아에 미치는 영향 (Effect of Intake L-Arginine on Athletic Performance, Lactate, Lactate Dehydrogenase and Ammonia in Male College Taekwondo Kyorugi Players during an 8-Week Intensive Winter Training)

  • 박경현;고수한;김태규;손선영;하수민;김도연
    • 한국응용과학기술학회지
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    • 제40권6호
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    • pp.1309-1321
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    • 2023
  • 본 연구는 8주간의 고강도 동계 훈련 시 L-아르기닌 섭취가 남자 대학 태권도 겨루기 선수의 경기수행능력, 젖산, 젖산탈수소효소 및 암모니아에 미치는 영향을 구명하기 위해 L-아르기닌 섭취군(n=14), 위약군(n=14)으로 구분하여 실시하였다. L-아르기닌 섭취군은 일일 아침 1 g, 점심 1 g, 저녁 1 g으로 총 3 g 섭취하였고 위약군은 말토덱스트린을 동일한 방법으로 섭취하였다. 8주간의 동계 훈련 프로그램은 70-90%HRR로 실시하였다. 측정된 자료의 L-아르기닌 섭취군과 위약군 간의 그룹 및 시기 간 상호작용 효과는 two-way repeated measures ANOVA, 그룹 내 시기 간 차이는 paired t-test를 사용하였으며, 그룹 간 차이는 independent t-test를 사용하여 분석하였다. 그 결과 TAAA (Taekwondo-specific aerobic anaerobic agility) test를 통한 경기수행능력 중 평균 발차기 수에서 그룹×시기 간 상호작용 효과가 나타났으며 그룹 간 주효과가 나타났다(p<.05). 또한, 발차기 피로지수에서 그룹×시기 간 상호작용 효과가 나타났다(p<.05). 한편, 젖산에서는 시기 간 주효과가 나타났으며(p<.05) 젖산탈수소효소에서 상호작용 효과 및 시기 간 주효과 나타났다(p<.05). 암모니아의 경우 그룹×시기 간 상호작용 효과가 나타났다(p<.05). 이러한 결과는 남자 대학 태권도 겨루기 선수의 고강도 훈련 후 피로에 쉽게 노출되는 선수들에게 L-아르기닌 섭취로 인해 체내 피로 유발 물질들을 신속하게 제거하는 데 긍정적인 역할을 할 수 있다고 사료된다. 따라서 고강도 엘리트 태권도 겨루기 운동선수의 경기수행능력 향상과 피로 회복 방법으로 L-아르기닌 섭취를 권장한다.

FEM을 이용한 상용차용 S-cam 브레이크슈의 구조해석 (Structural Analysis of S-cam Brake Shoe for Commercial Vehicle by FEM)

  • 서창민;지현철
    • 한국해양공학회지
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    • 제23권4호
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    • pp.69-77
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    • 2009
  • Structural analysis of a brake shoe for commercial vehicle was performed using finite element method. Since the strength of a brake shoe is affected by the magnitude and distribution shape of the contact pressure with the drum, the contact pressure between the shoe friction material and drum was calculated using a 2-Dimensional non-linear contact analysis in a state. And the brake was actuated by input air pressure and the drum of it was calculated both stationary and dynamic based on forced torque applied to the drum during the static state analysis. The results of the above analysis were then used as the load boundary conditions for a 3-Dimensional shoe model analysis to determine the maximum strain on the shoes. In the analysis model, the values of tensile test were used for the material properties of the brake shoes and drum, while the values of compression test were used for the friction material. We assumed it as linear variation, even though the properties of friction material were actually non-linear. The experiments were carried out under the same analysis conditions used for fatigue test and under the same brake system which equipped with a brake drum based on the actual axle state in a vehicle. The strains were measured at the same locations where the analysis was performed on the shoes. The obtained results of the experiment matched well with those from the analysis. Consequently, the model used in this study was able to determine the stress at the maximum air pressure at the braking system, thereby a modified shoe model in facilitating was satisfied with the required endurance strength in the vehicle.

X20CrMoV12.1강의 열화에 따른 기계적특성 평가 (The Evaluation of Mechanical Property of X20CrMoV12.1 Boiler Tube Steels)

  • 김범수;이성호;김두수;정남근
    • 동력기계공학회지
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    • 제8권3호
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    • pp.18-22
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    • 2004
  • Boiler is one of the most important utilities providing steam to turbine in order to supply mechanical energy in thermal power plant. It is composed of thousands of tubes for high efficient heat transfer. The material for boiler tubes is used in such high temperature and pressure condition as $540^{\circ}C$, 22MPa. The boiler tube material is required to resist creep damage, fatigue cracking, and corrosion damages. 2.25%Cr-1Mo steel is used for conventional boiler tubes, and austenitenite stainless steel is used for higher temperature boiler tubes. But the temperature and pressure of steam in power plant became higher for high plant efficiency. So, the property of boiler tube material must be upgaded to fit the plant property. Several boiler tube material was developed to fit such conditions. X20CrMoV12.1 steel is also developed in 1980's and used for superheater and reheater tubes in supercritical boilers. The material has martensite microstructures which is difficult to evaluate the degradation. In this thesis, degrade the X20CrMoV12.1 steel at high temperatures in electric furnace, and evaluate hardness with Vickers hardness tester and strengths with Indentation tester.

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층간분리 형상계수($F_s$)가 FRMLs의 층간분리 성장률($dA_D/da$)에 미치는 영향 (The Effect of Delamination Shape Factor, $f_s$ on the Delamination Growth Rate, $dA_D/da$ in FRMLs)

  • 송삼홍;이원평;김광래;김철웅
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 2003년도 춘계학술대회 논문집
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    • pp.398-404
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    • 2003
  • Most previous researches for the hybrid composite materials such as FRMLs(Al/AFRP, Al/GFRP) have evaluated the fatigue delamination behavior using the traditional fracture mechanism. However, most previous researches have not generally been firmed yet. Because delamination growth behavior in hybrid composite should be consider delamination growth rate, $dA_D$/da using the delamination shape factors, fs instead of traditional fracture mechanic parameters. The major purpose of this study was to evaluate the relationship between delamination shape factor, fs and delamination growth rate, $dA_D$ . And a propose parameter on the delamination aspect ratio, b/a. The details of the study are as follow : 1) Relationship between crack length, a and delamination width,b. 2) Relationship between delamination aspect ration, b/a and delamination area rate,($(A_D)_{N}(A_D)_{ALL}$. 3) Variation of delamination growth rate, $dA_D/da$ was attendant on delamination shape factors, $fs_1$, $fs_2$, $fs_3$. The test results indicated the delamination growth rate depends on delamination shape factors.

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통증(痛症)의 한방치료(韓方治療)에 관(關)한 소고(小考) (A Study on the treatment of pain in oriental medicine)

  • 류경주
    • 한국한의학연구원논문집
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    • 제2권1호
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    • pp.454-484
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    • 1996
  • There are many factors to evoke pain, for example cold, heat, seven emotion, digestion, fatigue, venemous worms, deficiency of blood etc., and its pathogenesis is complicated. Treatments for pain in oriental medicine are as follows. 1. Pharmacotherapy is a method to treat pain by different effects of herbal medicine, for example, regulating vital energy, activating blood circulation, eliminating phlegm, and dispelling the cold evil etc. 2. Acupuncture and moxibustion therapy is a kind of external application, it has a distinct effect in relieving pain. Recently its operation method has been more developed, so new acupuncture therapies are used in clinics. There are electroacupuncture, auricular acupuncture and injection of drugs at an acupuncture points etc. 3. Oriental physiotherapy is a treatment method to stimulate acupuncture points and meridians. (1) Hot pack, Paraffin bath, Microwave, Ultrasound, Short wave, Infra-red etc. are used to treat cold syndrome by dispersing cold by warming the channels. (2) E.S.T., I.C.T., T.E.N.S., S.S.P., cupping treatment etc. are used to treat disorders of vital energy. (3) Health ion, Carbon, T.D.P., etc are used to treat conic and deficiency syndrome.

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Phase 4, Post-Marketing Safety Surveillance of the MF59-Adjuvanted Influenza Vaccines FLUAD® and VANTAFLU® in South Korean Subjects Aged ≥65 Years

  • Yoo, Byung Wook;Kim, Chang Oh;Izu, Allen;Arora, Ashwani Kumar;Heijnen, Esther
    • Infection and chemotherapy
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    • 제50권4호
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    • pp.301-310
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    • 2018
  • Backgroud: Influenza vaccination is recommended for adults aged ${\geq}65$ years as they are at high risk of significant morbidity and mortality. This open-label, multicenter, post-marketing surveillance study assessed the safety of the MF59-adjuvanted trivalent inactivated subunit influenza vaccine, which is marketed as $FLUAD^{(R)}$ and $VANTAFLU^{(R)}$, in South Korean subjects aged ${\geq}65$ years. Materials and Methods: Solicited local and systemic adverse events (AEs) were collected from day 1 to 4 of the study. All unsolicited AEs and serious AEs (SAEs) were recorded from day 1 until study termination (day 29). Results: Of the 770 subjects enrolled ($FLUAD^{(R)}$, n = 389; $VANTAFLU^{(R)}$, n = 381), 39% overall experienced any solicited AE. Local AEs were reported by 33% of subjects overall; with the most common events being injection-site pain (30%) and tenderness (27%). Systemic AEs were reported by 19% of subjects overall with the most common events being myalgia (11%) and fatigue (8%). Conclusion: These results show that the MF59-adjuvanted influenza vaccine known as $FLUAD^{(R)}$ or $VANTAFLU^{(R)}$ had acceptable safety profiles in older adults (aged ${\geq}65$ years) in South Korea.