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        검색결과 41

        2.
        2024.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study identifies the possibility of alignment discrepancies during mortar firing when using inactive fuzes, which make it impossible to visually observe impact points. To address this issue, we studied a quality assurance method for Sight Alignment after firing. To establish a baseline, we analyzed the pre-firing Sight Alignment and the impact group status during firing for 00 mortars and 000 shells. Based on this analysis, we derived the alignment position information range after firing for 36 mortars, distinguishing between 68% and 95% confidence interval. Finally, considering data characteristics, inspection time requirements, and non-conforming data, we selected the Sight Alignment range after firing based on the 95% confidence interval. This study is expected to contribute to the development of quality assurance methods for munitions by serving as an example of quality assurance in the mass production stage of mortars.
        4,000원
        3.
        2024.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        As the demand for electric vehicles increases, the stability of batteries has become one of the most significant issues. The battery housing, which protects the battery from external stimuli such as vibration, shock, and heat, is the crucial element in resolving safety problems. Conventional metal battery housings are being converted into polymer composites due to their lightweight and improved corrosion resistance to moisture. The transition to polymer composites requires high mechanical strength, electrical insulation, and thermal stability. In this paper, we proposes a high-strength nanocomposite made by infiltrating epoxy into a 3D aligned h-BN structure. The developed 3D aligned h-BN/epoxy composite not only exhibits a high compressive strength (108 MPa) but also demonstrates excellent electrical insulation and thermal stability, with a stable electrical resistivity at 200 °C and a low thermal expansion coefficient (11.46×ppm/°C), respectively.
        4,000원
        5.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        정서적 양극화(affective polarization)에 관한 그동안의 연구들은 그 이론적 시각의 차이에도 불구하고 정서적 양극화가 당파적 정렬(partisan sorting)과 관련되어 있을 가능성을 시사한다. 이에 이 연구는 한국 유권 자들의 정서적 양극화와 이념적 정렬(ideological sorting)의 관계를 18 대, 19대, 20대 대통령선거 여론조사 결과를 이용하여 살펴보았다. 분석 결과, 우선 한국 유권자들의 정서적 양극화와 이념적 정렬은 동시에 진 행되었다고 할 수 있다. 즉, 18대 대선 이후 양당 지지자들이 점차 진보 와 보수로 결집하면서 동시에 이들 사이의 정서적 양극화가 심화한 것이 다. 또한, 이러한 이념적 차이의 확대와 정서적 양극화는 실제로 밀접한 연관이 있었던 것으로 나타났다. 핵심적으로, 지난 세 차례 대선을 거치 면서 이념 성향이 정서적 양극화에 미친 영향은 계속해서 강해졌다. 이 것은 이념적 정렬에 따른 양당 지지자들 사이의 이념적 차이의 확대가 정서적 양극화에 영향을 미쳤다는 것을 의미한다. 종합적으로, 이 연구는 적어도 18대 대선 이후 한국 유권자들의 정서적 양극화가 이념적 정렬과 밀접한 연관이 있었다는 것을 시사한다. 정서적 양극화의 원인 중 하나 가 이념적 차이의 확대일 수 있는 것이다.
        5,800원
        6.
        2022.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : Presently, it is impossible to evaluate the actual number of operational plans and punctuality of bus routes. In this study, a methodology for separating bus stops and sorting departure orders was developed using city bus operation information, and its field applicability was examined. METHODS : Based on current bus data, the "moving speed (km/h)," "Lag data," and "Lead data" were generated. The number of stops was classified based on the location where the order of the stops changed for each vehicle, and an arbitrary ID was assigned for each number of stops. In the case of a preceding vehicle, for each rotation information, a time interval was calculated based on the same point, and the rotation with the smallest time interval was determined as the preceding vehicle. RESULTS : An evaluation was conducted on Bus Route 201 in Daejeon. The vehicles were classified based on the operation data of the previous day. From analyzing the operation time and distance for each operation based on the last stop and starting point, it was found that both the number of operation plans and performance were consistent. The punctuality was analyzed and was found to be inversely proportional to the difference between the stop arrival time and preset arrival time, preset dispatch interval, and actual dispatch interval. The on-time(regularity) ratio was determined as 98.0% and the early departure ratio was 99.3%, indicating very good regularity. CONCLUSIONS : The research results can be used by local governments with insufficient levels of public transportation-based data management, and can be used as basic data for establishing public transportation policies. The results of this study can be referred to when evaluating the transparency of financial support for public transportation operators and operations, with the aim of enhancing public transportation services.
        4,000원
        7.
        2022.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: Neck pain is a major health problem in developed countries and has a lifetime prevalence of 50%. Major problems include a reduced cervical range of motion, muscle stiffness, dysfunction, postural changes, and decrease in psychosocial level. Objects: This study aimed to investigate the effects of applying the upper trapezius inhibition dynamic taping to patients with chronic neck pain on their neck pain, functional level, cervical range of motion, psychosocial level, and neck posture. Methods: The study design was a randomized controlled trial. A total of 40 patients with neck pain participated in this study and were randomly assigned to a Dynamic Taping group (n = 20) or Sham Taping group (n = 20). In both groups, basic intervention cervical pain control therapy and shoulder stabilization exercise program were performed. In addition, dynamic taping and sham taping were applied to participants in the Dynamic Taping and Sham Taping groups to inhibit the trapezius muscle, respectively. All interventions were performed three times a week and a total of 12 times for 4 weeks, and the participants’ neck pain, functional impairment level, cervical range of motion, psychosocial level, and neck posture were measured and compared before and after the intervention. Results: Both groups showed significant differences in neck pain, functional level, cervical range of motion, psychosocial level, and neck postural before and after the intervention (p < 0.05). Moreover, there were significant differences between the two groups regarding the functional level and neck posture (p < 0.05). Conclusion: Inhibition dynamic taping of the upper trapezius muscle suppression is an effective method with clinical significance in reducing pain in individuals with chronic neck pain and improving the functional level, cervical range of motion, psychosocial level, and neck posture.
        4,000원
        8.
        2021.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        목적 : 주시시차 각을 교정해주는 정렬프리즘과 Sheard 기준에 의한 프리즘 처방 값을 비교하여 차이를 알아보 고자 한다. 방법 : 전신질환이나 안과질환이 없으며 사시에 관한 수술을 받은 적이 없는 성인 35명(평균 25.43±2.23세, 남자27명, 여자8명)을 대상으로 하였다. 주시시차는 Wesson fixation disparity card를 이용하여 측정한 후, 프리즘바를 이용하여 주시시차를 0으로 만드는 프리즘량을 정렬프리즘으로 기록하였다. 사위도 검사는 수정된 토링 톤 법으로 Muscle Imbalance Measure card를 이용하였다. 결과 : 주시시차의 평균은 외주시시차 9.95±5.69′이었고, 프리즘바를 이용한 주시시차의 정렬프리즘 교정 값 은 외주시시차 4.09±2.80 △이었다. 사위도는 외사위 8.34±5.70 △, 양성융합버전스는 23.20±6.28 △이었고, Sheard 기준에 의한 프리즘 처방 값은 기저내방 0.66±1.41 △이었다. 주시시차의 정렬프리즘과 Sheard 기준에 의한 프리즘 처방 값의 평균은 통계적으로 유의한 차이를 보였다(p<0.001). 결론 : 동일한 주시시차의 각을 가지고 있더라도 주시시차 각을 교정해주는 정렬프리즘량이 사람마다 다른 경향을 보였다. 따라서 사위 처방을 하고자 할 때 주시시차를 위한 정렬프리즘과 Sheard 기준을 모두 고려해야 할 것으로 사료된다.
        4,000원
        10.
        2020.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        목적 : 골프공과 퍼터의 조준보조선의 유무, 개수 및 골프 경력이 퍼팅 시 정렬에 미치는 영향을 분석하고자 하였다. 방법 : 최근 1년간 필드에서 자신의 평균 점수를 알고 사시와 약시가 없는 43명(48.3±10.07세 및 –0.07± 0.74 logMAR)을 대상자로 선정하였으며, 퍼팅 거리 1.5 m 및 3 m에서 조준보조선이 0개, 1개 및 3개인 골프공 과 1개 및 3개인 퍼터를 이용하여 퍼팅 시 정렬 오차를 측정하였다. 결과 : 골프공 및 퍼터의 조준보조선의 유무, 개수 및 골프 경력에 따른 퍼팅 시 정렬 오차를 분석한 결과, 골 프공 정렬의 정확성은 조준보조선 및 핸디캡에 따른 영향이 없는 것으로 나타났다. 하지만, 퍼터 정렬의 정확성은 조준보조선이 1개인 퍼터에 비해 3개인 퍼터에서 증가한 것으로 나타났고 통계적으로 유의한 차이가 발견되었다. 예상 퍼팅 성공률과 주관적 만족도는 조준보조선이 1개인 골프공 및 퍼터에 비해 3개인 골프공 및 퍼터에서 모두 증가하였다. 결론 : 골프공 및 퍼터의 정렬은 전체 퍼팅 수행 과정의 일부분이며, 골프공 및 퍼터의 조준보조선은 정렬 오차 를 일부 감소시키는 것으로 나타났다. 하지만 보다 명확한 분석을 위해 운동학적 측면과 시기능을 모두 고려한 후 속 연구가 반드시 필요할 것으로 생각된다.
        4,500원
        12.
        2020.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Load carrying capacity(LCC) can be reduced from its design value as a result of film thickness change when a journal is misaligned and some part of bearing is unintentionally translated. In this study, the numerical solution of the incompressible Reynolds equation was obtained by using the finite difference method and mass conservation algorithm (JFO boundary condition) with periodic pressure distribution in circumferential direction to analyze the change of LCC due to journal misalignment and step change of film thickness in axial direction for a journal bearing of vertical pumps. Smallest LCC in each eccentricity ratio is obtained as two angular positions are changed – an angular position where misalignment occurs, and another angular position where the axial step takes place while the degree of misalignment is fixed at 90%. Compared with the reaction force of plain journal bearing, the LCC reduced as much as 26.7% due to geometric effects of journal bearing at the eccentricity ratio of 0.9, while the step height is no higher than 0.1 times of bearing clearance.
        4,000원
        13.
        2019.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, the structural stability of an align unit was studied to investigate the deformation and vibration characteristics of the upper and lower modules of the align unit during LCD panel transfer. The align unit consists of upper module and lower module. SolidWorks Simulation was used to analyze the structure, fatigue, and modes, to understand the deformation and vibration of the stiffness of the align unit. Because of the upper eccentric structure of the align unit, the main strain was large at the contact of the upper and lower modules and at the bottom of the support, and more pronounced at it’s front. The stress was large in the front support of the upper and lower modules, and the displacement was observed in the front of the upper module. The minimum life cycle that indicates the structural integrity of the align unit has exceeded its usable number. Also, the increase in natural frequency of the align unit gradually slowed down, as the vibration mode increased.
        4,000원
        14.
        2019.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        I investigated the homogeneous liquid crystal alignment using parallel patterning on nickel oxide thin film. Nickel oxide thin film was prepared by sol-gel process, which is and cost effective method to form oxide thin film. Since the sol-gel process is solution driven method, the patterning on nickel oxide can be achieved by imprinting lithography. Nickel oxide with parallel pattern was used for liquid crystal alignment layer, which can be a alternative to conventional rubbing process to aligning a liquid crystal molecules. As a result, a high transmittance of 83.9% was confirmed for the NiO film, and a stable horizontal orientation pretilt angle of 0.2° occurred in the imprinted NiO film. These results were judged to be a positive level that can be commercialized in the horizontal alignment type liquid crystal display that is currently used universally. Anisotropic characteristics of nickel oxide induced by a parallel pattern leads to the alignment of liquid crystals.
        3,000원
        15.
        2019.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Abstract We demonstrate convenient alignment technologies using imprinting lithography with sol-gel process. The aligned nano pattern is fabricated on a silicon wafer by laser interference lithography. For conformal imprinting process, aligned nano pattern was transferred onto the polydimethylsiloxane (PDMS). Using a PDMS sheet with aligned nano pattern, aligned nano pattern was created onto the sol-gel driven hafnium zinc oxide by imprinting lithography. The process was conducted at annealing temperatures of 150 °C. The obtained pattern on the HfZnO film acted as a guide for aligning liquid crystal (LC) molecules. The geometric restriction induced by aligned pattern leads to LC alignment along to the aligned nano pattern. The combination of imprint lithography and solution-processed inorganic materials proved good alternative of LC alignment technique.
        4,000원
        16.
        2019.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, the yaw misalignment value of wind turbine was measured using Lidar and it was analyzed the effect of vibration reduction and power performance improvement when applied to turbine. It was confirmed that the vibration of the main bearing and the gear box of the wind turbine was partially reduced. Also it was found that the output performance was improved when the wind speed was over 8m/s. As a result, it was also found that the annual energy production(AEP) was improved when the average annual wind speed of the wind farm was over 6m/s. Converted to AEP, the AEP improved about 1% and 4%, when the annual wind speed was 6m/s and 11m/s respectively, which resulted in an improvement of about 1~4% through the yaw misalignment correction of the wind turbine.
        4,000원
        17.
        2018.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        갭색법(gap & sag method)은 선박 건조과정에서 축을 조립하기 전 최종적으로 축이 축계정렬 설계치와 동일한 위치에 거치되었는지의 여부를 확인하기 위해 사용되고 있는 방법이며, 조립 전 프로펠러축을 기준축으로 하여 양 축의 플랜지에서 축 자중에 의해 발생하는 갭색값을 통해 나머지 축계의 위치를 순차적으로 확정해 나간다. 만일 설계치와 다르게 기준축이 거치되는 경우 연쇄적으로 나머지 축의 거치에 영향을 주게 된다. 또한, 축 조립 후 검증과정에서 측정된 베어링 반력이 설령 설계치를 만족하더라도 선미관 후부측에서의 프로펠러축과 베어링간 상대적경사각을 추정할 수 없게 됨으로써 결과적으로 축계의 안정성에 부정적인 영향을 미칠 수 있다. 이러한 문제를 해결하기 위하여 본 연구에서는 실제 선미관 베어링 발열 및 개방검사 사례를 통해 선미관 베어링 유효지지점에 관한 이론계산 및 실측치분석 연구를 수행하고 이를 바탕으로 축계 정렬오차를 최소화하기 위한 축계 시공방법을 제안하였다.
        4,000원
        18.
        2017.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Urchin-structured zinc oxide(ZnO) nanorod(NR) gas sensors were successfully demonstrated on a polyimide(PI) substrate, using single wall carbon nanotubes(SWCNTs) as the electrode. The ZnO NRs were grown with ZnO shells arranged at regular intervals to form a network structure with maximized surface area. The high surface area and numerous junctions of the NR network structure was the key to excellent gas sensing performance. Moreover, the SWCNTs formed a junction barrier with the ZnO which further improved sensor characteristics. The fabricated urchin-structured ZnO NR gas sensors exhibited superior performance upon NO2 exposure with a stable response of 110, fast rise and decay times of 38 and 24 sec, respectively. Comparative analyses revealed that the high performance of the sensors was due to a combination of high surface area, numerous active junction points, and the use of the SWCNTs electrode. Furthermore, the urchin-structured ZnO NR gas sensors showed sustainable mechanical stability. Although degradation of the devices progressed during repeated flexibility tests, the sensors were still operational even after 10000 cycles of a bending test with a radius of curvature of 5 mm.
        4,000원
        20.
        2016.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: Total knee arthroplasty (TKA) recovers the alignment of the knee joint, but fails to automatically restore the alignment and function of the hip and ankle joints. It may affect the alignment and stability of the knee joint, therefore therapeutic intervention in hip and ankle joint is necessary for the rehabilitation process after TKA. Objects: The aim of this study was to comparison of the effects of the two exercise methods on the coronal plane alignment after TKA. This study conducted an experiment by dividing subjects into a lower extremity isometric co-contraction group (LEIC) and a quadriceps isolated isometric contraction (QIIC) group. Methods: A total of 37 subjects were randomly assigned to the LEIC (n1=19) or the QIIC (n2=18). Exercise was applied to five times per week for three weeks, starting on the eighth day after surgery. Range of motion exercises were performed as a common intervention and then each group performed quadriceps isometric contraction exercises with 10 sets of 5 repetitions. Radiological imaging was performed prior to surgery, one month and six months after surgery. In addition, the hip-knee-ankle angle (HKA) and tibiotalar angle (TTA) were measured. Results: The HKA was close to neutral in the LEIC rather than the QIIC (p<.05). The LEIC showed varus and the QIIC exhibited valgus TTA (p<.05). In a comparison of HKA and TTA over time, there was no significant change in either group (p>.05). According to the comparison of the TTA before surgery, the LEIC showed significant changes in the varus direction (p<.05), while there was no significant change in the QIIC (p>.05). Conclusion: The LEIC method triggered changes in the TTA and brought the HKA close to the neutral. Thus, LEIC is more effective than QIIC in creating stability in the coronal plane alignment of the knee and ankle joints after TKA.
        4,200원
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