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        검색결과 280

        81.
        2017.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: The multiple hop test is an active performance test that has been commonly used to assess individuals with functional ankle instability. Previous studies have suggested that insufficiency of dynamic postural stability and passive stability during dynamic activities can have an influence on performance in the multiple hop test. However, no study has investigated the effects of dynamic postural stability training and ankle bracing on multiple hop test performance in individuals with functional ankle instability. Objects: The purpose of this study was to compare the immediate effects of dynamic postural stability training versus ankle bracing in the performance of the multiple hop test for participants with functional ankle instability. Methods: Twenty-nine participants with functional ankle instability who scored below 24 in the Cumberland Ankle Instability Tool were selected. The participants were randomly divided into two groups: a dynamic postural stability training group (n1=14) and an ankle bracing control group (n2=15). The multiple hop tests were performed before and after applying each intervention. Dynamic postural stability training was performed using visual-feedback-based balance-training equipment; participants in this group were asked to perform a heel raise in a standing position while watching the centering of their forefoot pressure to prevent excessive ankle inversion. Ankle bracing was applied in the control group. Results: When comparing the pre- and post-intervention period for both groups, both methods significantly improved the results of the multiple hop test (p<.05). However, no significant differences were shown between the dynamic postural stability training and ankle bracing groups (p>.05). Conclusion: Both dynamic postural stability training and ankle bracing showed significant improvement (2.85 seconds and 2.05 seconds, respectively) in test performance. Further study is needed to determine the long-term effects of dynamic postural stability training and to determine whether insufficient dynamic postural stability is a causative factor for functional ankle instability.
        4,000원
        82.
        2017.02 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        미리찌 증후군은 담낭절제술을 받은 환자들 중 2% 이하를 차지하는 드문 질환이다. 담낭관 변이와 동반된 미리찌 증후 군의 경우는 수술 중 변이의 발견이 어렵고, 수술 후 합병증이 높아 수술적 치료에 어려움이 있다. 본 증례는 과거 복강경 담 낭절제술을 받은 상태에서, 담관염 소견으로 방문하여 저위 합류 담낭관의 잔여 담낭관에 담석이 감돈되어 발생한 미리 찌 증후군을 진단하고, 내시경으로 성공적으로 치료한 사례 이다. 저위합류 담낭관과 같은 해부학적 변이를 동반한 미리 찌 증후군의 경우 수술적 치료가 어렵거나, 불완전할 수 있다. 이에 내시경 역행담췌관조영술을 통한 인공배액관 삽입술 및 UDCA 약물요법 이후 풍선확장술을 이용한 담석 제거술이 수술적 치료의 대안 치료로 고려될 수 있다.
        4,000원
        83.
        2017.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 논문에서는 이종재질로 구성된 세장비가 큰 보의 차원축소와 복원의 효율성과 정확성을 입증하기 위하여 VABS와 3차원 유한요소해석 모델의 결과와 비교하였다. 그리고 3차원 유한요소모델과 차원축소 모델을 가상균열닫힘법을 이용하여 에너지 해방률을 계산하였다. 원형과 사각형의 단면에 초기 크랙을 가진 수치모델을 이용하여 보의 차원축소와 복원기법 및 가상균 열닫힘법을 이용하여 복원해석 결과 및 에너지 해방률을 비교하여 효율성과 정확성을 입증하였다. 특히 제시된 에너지 해방률 계산 기법은 고고도 무인기의 날개, 헬리콥터 로터 블레이드, 풍력 블레이드, 틸트로터 등의 정적, 동적 모델링 및 수명평가에 활용될 수 있을 것이다.
        4,000원
        84.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This paper studies the effect of a playtykurtic excitation signal on fatigue life. In general, a vibration test uses an excitation signal having a normal distribution of kurtosis 3. However, a vibration signal generated in a product’s operation environment has usually a non-normal distribution. This paper uses ZMNL method to generate a playtykurtic excitation signal having the equivalent power spectrum density with a reference vibration profile. This paper proposes a method which uses a fatigue damage spectrum ratio for studying the effect of a playtykurtic excitation signal on fatigue life. The fatigue spectrum damage ratio is obtained by dividing a fatigue damage spectrum acquired using the acceleration profile in which all conditions are the same except for the kurtosis by a fatigue damage spectrum acquired theoretically. This paper shows that the signal of kurtosis less than 3 can increase the fatigue damage spectrum by more than 2 to 4 times compared to the signal of kurtosis 3 using the fatigue damage spectrum ratio.
        4,000원
        85.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Seismic design of braced frames that simultaneously considers economic issues and structural performance represents a rather complicated engineering problem, and therefore, a systematic and well-established methodology is needed. This study proposes a multi-objective seismic design method for an inverted V-braced frame with suspended zipper struts that uses the non-dominated sorting genetic algorithm-II(NSGA-II). The structural weight and the maximum inter-story drift ratio as the objective functions are simultaneously minimized to optimize the cost and seismic performance of the structure. To investigate which of strength- and performance-based design criteria for braced frames is the critical design condition, the constraint conditions on the two design methods are simultaneously considered (i.e. the constraint conditions based on the strength and plastic deformation of members). The linear static analysis method and the nonlinear static analysis method are adopted to check the strength- and plastic deformation-based design constraints, respectively. The proposed optimal method are applied to three- and six-story steel frame examples, and the solutions improved for the considered objective functions were found.
        4,000원
        86.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Purpose: The purpose of this study was to investigate the effects of communication simulation based on for elderly sensation disorders patient. the elderly population is growing about hearing loss, cataracts on this communication simulation for a nursing student is required. Methods: A nonequivalent control group pretest-posttest design was used. A total of 46 subjects (undergraduate students) participated in they were assigned to two groups: the experimental group(n=24) the control group (n=22). Data - gathering structured questionnaires that included communication competence, academic self-efficacy, and attitude about the elderly. The data were collected and statistical analyses were conducted with x2 test and independent t-test using the SPSS 22.0 program. Results: there was significant improvement in communication competence in the experiment group (t=2.05, =.046) and attitude about the elderly (t=-2.26, p=.033). However, there was no statistically no significant in academic self-efficacy(t=1.17, p=.247) Conclusion: communication Simulation should continue to be developed further for better sensation disorders with elderly patient. Integrated education in particular using a high-fidelity simulator will contribute to improvement in nursing competence.
        4,500원
        87.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The presence of the microorganisms of untreated canals is one of the main reasons of the failure in the endodontic treatment. The knowledge of variations in the canal systems of the tooth is important for the successful endodontic treatment. In the maxillary molars, the presence of the two separate palatal roots is very rare variations. Although there have been several case reports of maxillary first and second molars, the case reports of maxillary third molars are very few. This case report presents the endodontic treatment of a maxillary third molar with two separate palatal roots. It is important to notice the clinical signs and analyze the radiographs carefully. The use of a microscope is helpful for the visualization of pulpal chamber, and pulpal chamber floor should be investigated thoroughly with endodontic explorer. The straight-line access for all the canal orifices is important for the success in the endodontic trea
        4,000원
        88.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The National Institute of Horticultural & Herbal Science achieved the breeding of the moon cactus cultivar ‘Hahong’ with dark red color in 2013. Initially, the red dark colored 'Seolhong' and 'Gohong' cultivars were crossed in 2009. Their seeds were harvested after 2 months, sterilized by C2H5OH 70% and NaOCl 2%, and then sowed in 100 mL flasks filled with Kyoto medium + Charcoal 0.1%. The bottom of the germinated shoot was cut, grafted in vitro into a young vine cactus, Hylocereus trigonus, and then planted in a test tube with the same medium. After 6 months, the young grafted cactus was moved into the greenhouse and hardened for 7 days. The cactus was grafted in vivo once a year for four years, the characteristics of growth were surveyed three times from 2011 to 2013, according to the guidelines for the conduct of tests for distinctness, uniformity and stability of Gymnocalycium mihanovichii. ‘Hahong’ has a flat round shape, dark red skin color (R 46B), an average of 8.3 ribs (8 – 10 ribs) similar to ‘Seolhong’. The spine on the body has gray and brown colors and grows up to 4.1 mm in average in a straight shape. The tubercle on the rib is projecting, with a diameter of 39.6 mm, and produces 14.2 offsets in average at 10 months from planting. The preference score for this cactus is 4.2 on a five-point scale. On June 1, 2015, ‘Hahong’ was registered (registration No. 5561) and is now protected by Korean Seed Industry Law.
        4,000원
        89.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, effectiveness of seismic retrofitting methods using passive damping devices was investigated through numerical analyses of short-period structures under earthquakes which have short-duration and high-frequency impulse characteristics similar to Geyongju earthquakes. Displacement spectra of elastic systems and ductility demand of inelastic systems were evaluated by increasing viscous or friction damping. The damping devices could reduce responses of the structures with shorter structural period than 0.2s. The earthquakes similar to impulse load did not induce the responses of the structures with longer period than 0.4s, and the effects of the damping devices which generates damping forces proportional to structural responses became insignificant.
        4,000원
        90.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this paper, time and frequency domain characteristics of Gyeong-ju earthquakes were investigated, and nonlinear time history analyses were conducted for bi-linear hysteretic structures excited by short-duration ground accelerations. Previous studies showed that larger inelastic displacements than the peak displacement of the corresponding elastic system were observed especially for the structures with structural period shorter than 0.3s, and the similar results could be obtained when long-duration ground accelerations were used as excitation loads. For the short-duration earthquakes, however, the inelastic displacements were not so large and almost identical to the peak elastic displacements.
        4,000원
        91.
        2016.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Composite materials have the strong durability and light weight as inhomogeneous material. These material are manufactured by combining and maximizing the advantage of each material. Among these various materials, stainless steel, aluminum and brass has been used generally. Prior to using, the preparatory experiments are demanded in order to obtain the material strengths. In this study, the tensile tests are carried out with the specimens of stainless steel, aluminum and brass. These tensile specimens of same standards are made with the notches at both sides of specimen. When the forced displacement of about 11 mm proceeds in case of stainless steel specimen, the maximum load of 31000 N is shown simultaneously with the fracture of specimen. When the forced displacement of about 6 mm proceeds in case of aluminum specimen, the maximum load of 20600 N is shown simultaneously with the fracture of specimen. When the forced displacement of about 7 mm proceeds in case of brass specimen, the maximum load of 25000 N is shown. In this study, the finite element analysis as ANSYS program is carried out in order to verify these experimental results. The experimental and analysis results are similarly shown each other. Through the result of this study, the analysis data with no experiments are thought to be trustworthy as the tensile experimental data.
        4,000원
        92.
        2016.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 논문에서는 풍력 블레이드와 같이 세장비가 크고 초기 비틀림이 존재하는 복합재료로 구성된 블레이드에 대한 이차원 단면의 차원축소와 복원관계를 이론적으로 기술하였다. 그리고 VABS 이용한 보의 차원축소모델에 대한 유효성을 검증하기 위해 선행연구 모델을 활용하여 기존 연구결과를 수치적으로 비교하였다. 실물과 가장 가까운 날개 구조물 2차원 형상에 단 면해석을 적용하여 정밀한 단면의 이산화를 수행하고 VABS를 이용하여 블레이드의 특성(질량행렬, 강성행렬)을 포함한 1 차원 보 모델링을 수행하였다. 1차원 보 모델을 통해 세장비가 큰 날개 구조물의 거동을 확인하고 내부하중을 계산하여 단 면위치에서 변형률 복원을 수치적으로 계산하고 이산화된 단면에 수치적으로 매핑하여 시각적으로 확인하고 여유마진을 계 산하였다.
        4,000원
        93.
        2016.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: A forward head posture (FHP) is one of the most common types of poor head posture in patients with neck disorder. A prolonged FHP might increase pressure on the posterior cranio-cervical structure and exhibit reduced performance on a cranio-cervical flexion test (CCFT). CCFT is included to activate deep cervical flexor muscles and inhibit excessive activation of superficial cervical flexor muscles. Therefore, the selective activation of deep cervical flexors is needed for effective exercise for FHP. Objects: The purpose of this study was to compare muscle thickness between longus colli (Lco) and sternocleidomastoid (SCM) using ultrasonography in subjects with FHP depending on head support. Methods: This was a cross-sectional, case-control research design study. The ultrasonographic images of Lco and SCM were taken in 17 subjects with FHP during the 5 phases of the CCFT with and without a head support. Towel was used for supporting head to make the neutral head position in supine. Changes in muscle thickness during the test were calculated to infer muscle activation. Data were analyzed using repeated measures of two-way analysis of variance with the significance level of .05. Results: When subjects performed the CCFT with head support, there was a significant difference in muscle thickness of Lco and SCM (p<.05). According to a post hoc paired t-test, change of thickness of Lco was greater at all phases, and change of thickness of SCM muscle was less at phase 4 and 5 in condition with head support (p<.01) compared to condition without head support (p<.01). Conclusion: The result of this study suggest that applying head support for neutral head position during CCFT could be a useful method for activating Lco muscle without excessive activation of SCM muscle.
        5,400원
        94.
        2016.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        CFRP hardened by carbon fiber and resin has the property of high strength and low weight. Specifically, the strong feature against the external vibration environment is shown as CFRP is designed with the structure of multi-axes. So, CFRP in place of metal has been used at the various fields. CFRP specimens for mode Ⅱ are applied with the repetitive fatigue load in this study. These specimens have the fiber layer angles of 30°, 45° and 60°. The material properties of specimens are investigated with the result of fatigue fracture due to this load. As the study result, the smallest and largest reaction forces of 500 N and 540 N are shown at the layer angle of 30° and 60° respectively among these specimens. The separation of adhesive interface at 4000 fatigue cycles is happened earliest in case of the layer angle of 60°. But the separation of adhesive interface at 11000 fatigue cycles is happened latest in case of the layer angle of 45°. Through the result of fatigue property, it is thought that the basis data can be applied to evaluate the safety at CFRP structure applied with fatigue.
        4,000원
        95.
        2016.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        마이크로지르코니아는 높은 내약품성, 높은 전기저항성 등의 우수한 열적 기계적 성질을 가지 므로 다양한 분야에 사용되어 진다. 또한 지르코니아 표면을 친수화시키면, 물에 대한 분산성이 우수하 여 분산이 용이할 뿐만 아니라 대부분의 오염물질은 소수성을 띄기 때문에 오염물질에 대한 저항성을 높일 수도 있다. 본 연구에서는 지르코니아 표면에 γ-aminopropyltrimethoxysilane (APS)을 사용하여 서로 다른 pH 조건에서의 가수분해와 축합반응을 통한 친수성기의 도입과 물에 대한 분산성을 조사하 고 γ-ureidopropyltrimethoxysilane (UPS)을 사용한 결과와도 비교하였다.친수화로 개질된 마이크로지르코니아에의 지르코니아 표면의 수산기와 가수분해된 실란의 수산기와의 공유결합의 존재는 FT-IR ATR spectroscopy 및 ninhydrin 반응을 통해 확인하였다. 그러나, SEM/EDS의 결과로는 지르코니아 표면에 도입된 Si의 존재는 확인할 수 없었다. 또한, 입도 분석 결과 마이크로지르코니아는 개질 반응 중 일부 입자의 파쇄 및 aggregation이 일어남을 알 수 있었다. APS 로 개질한 경우 pH가 중성일 때 수분산성이 향상되었으나, 0.5~2% 농도의 UPS로 개질된 경우는 모든 경우 수분산성이 향상되며 분산안정성도 우수하였다.
        4,000원
        96.
        2016.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        십이지장 구부로의 총담관의 이소성 개구는 매우 드물며, 담도 질환이나 재발성/불응성 십이지장 궤양과 관련이 있는 경우가 많다. 저자들은 직시경으로 확인하고 일부는 직시경을 이용한 내시경 역행성 담췌관 조영술로 동반된 담관염을 치료했던 3명의 환자들을 보고한다. 일부 환자에서는 직시경이 시술에 있어 더 효과적이고 유리한 시술환경을 제공할 수 있다.
        4,000원
        97.
        2016.05 구독 인증기관·개인회원 무료
        AEMFCs have been realized as a desirable alternative to PEMFCs. AEMs are the most important components of AEMFCs, and the high ion conductivity, good dimensional, mechanical and alkaline stabilities are required for AEMs. High conductivity mostly leads to a poor dimensional and mechanical stabilities. Chemical cross-linking of polymers have been attempted in an effort to overcome these problems, but the cross-linking inevitably reduced the conductivity due to the increased hydrophobicity of the membrane. Our group developed terminal crosslinking in which cross-linking was restricted only to the terminus of the polymer chains to minimize the loss of conductivity. Synthesis and properties of these terminally-crosslinked membranes will be detailed.
        98.
        2016.05 구독 인증기관·개인회원 무료
        현재 사용되는 전기탈이온(EDI)공정은 전기투석법과 이온교환수지법을 혼합한 공정이다. 이 공정은 전기투석을 위한 양/음이온교환막이 사용되고 두 막 사이 에 이온교환수지로 채워서 모듈을 제작한다. 전기탈이온공정은 농축수가 강한 산성과 염기성이기 때문에 전극의 손상과 같은 문제점을 초래한다. 이러한 문제 점을 해결하기 위해서 전기흡착탈이온(EAD)공정을 사용한다. 전기흡착탈이온공 정은 반대 전하 이온을 흡착시켜 제거하고 역전을 통해서 탈착시켜 이온교환기 를 재생시키는데, 이 때 재생시간이 필요하다. 따라서, 이온교환막을 Bipolar막으 로 제조하여 해결할 수 있고, 전기탈이온공정과 공통적으로 모듈을 작게 만들기 위해서 나노사이즈의 이온교환입자를 제조하여 별도의 처리과정 없이 성능을 구현하고자하였다. 본 연구는 현재 생산되고 있는 모듈보다 높은 이온교환능력 을 가지며 바인더 역할을 할 수 있는 고무상의 고분자를 합성하고 이온교환수 지대신 이온교환능을 가진 nano particle을 이용하여 복합막을 제조하였다.
        99.
        2016.05 구독 인증기관·개인회원 무료
        In olefin/paraffin separation process, new technology such as membrane separation process has been ever demanding for both economic and environmental reasons. facilitated olefin transport membrane, containing positively charged silver nanoparticles (Ag NPs) by electron acceptor 7,7,8,8-tetracyanoquinodimethane (TCNQ) as olefin carriers dispersed in poly(vinyl pyrrolidone) (PVP), shows extremely high separation performance for propylene/propane mixtures. However, higher permeance is always demanding for practical applications. In this study, POSSs were added to PVP/Ag NPs/TCNQ membranes. Among various kinds of POSS, trisilanolisooctyl POSS showed higher permeance with a moderate selectivity. Therefore it is concluded that mesoporous POSS is an effective additive in improving the gas permeance.
        100.
        2016.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Buzz, squeak, rattle noise that are referred as BSR have become important part in vehicle's quality because vehicle NVH(noise vibration harshness) reduction technology of main parts like engine and drive-line has made great progress except BSR noise. BSR test is progressed by composing many road excitation power spectrum density(PSD) profiles into a composite PSD profile. Shakers which are input by composite PSD profile make time histories(time-acceleration data) by aggregate of a large number of harmonics related with composite PSD profile in general. But when only composite PSD profile is input to shaker, the time histories from shakers exhibits Gaussian distribution characteristics and can't reflect all road excitation PSD profiles. In this study, we search other studies that try to solve the problems occurring when a shaker is input only PSD profile and analyze time histories resulted from BSR test to check ways of shaker's operation.
        4,000원
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