• 제목/요약/키워드: Use of force

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복합재료의 직교 절삭가공 특성에 관한 연구 (A study on the orthogonal cutting characteristics of glass fiber reinforced plastics)

  • 송화용;정용운;김준현;김주현
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 2001년도 추계학술대회(한국공작기계학회)
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    • pp.155-160
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    • 2001
  • In the use of glass fiber reinforced plastics(GFRP) it is often necessary to cut the components, but the cutting of GFRP is often made difficult by the delamination of the compositions and short tool life. Experimental investigation was conducted to evaluate the chip formation of the glass fiber reinforced plastics during orthogonal cutting. The chip formation process, cutting force, and thrust force were studied. The chip formation processes were studied through the use of quick-stop device. Chip-tool contact areas were obtained with the use of the quick-stop device, and observed using optical microscopy after polishing. Cutting force and thrust force were measured through the use of the tool dynamometer.

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Force identification by using specific forms of PVDF patches

  • Chesne, Simon;Pezerat, Charles
    • Smart Structures and Systems
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    • 제15권5호
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    • pp.1203-1214
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    • 2015
  • This paper deals with the experimental validation of the use of PVDF Patches for the assessment of spatial derivatives of displacement field. It focuses more exactly on the shear Force Identification by using Specific forms of PVDF patcHes (FISH) on beams. An overview of the theoretical approach is exposed. The principle is based on the use of the weak form of the equation of motion of the beam which allows the shear forces to be extracted at one edge of the sensor when this last has a specific form. The experimental validation is carried out with a cantilever steel beam, excited by a shaker at its free boundary. The validation consists in comparing the shear force measured by the designed sensor glued at the free edge and the directly measured force applied by the shaker. The sensor is made of two patches, called the "stiffness" patch and the "mass" patch. The use of both patches allows one to identify correctly the shear force on a large frequency domain. The use of only the stiffness patch is valid in the low frequency domain and has the advantage to have a frequency-independent gain that allows its use in real time.

Adopting Local Languages as Official Languages: Effect on Women and Rural Individuals' Labor Force in Burkina Faso

  • YAMEOGO, SOULEYMANE
    • KDI Journal of Economic Policy
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    • 제42권2호
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    • pp.31-56
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    • 2020
  • This study investigates the impact of the use of the main local languages in Burkina Faso (Moore, Dioula, Fulfulde) on labor force participation. Using Ethnologue language data, I compute the relative language distance reduction index, after which I use a probit/logit model and instrumental variable approach to account for language use policy endogeneity. This study finds that the use of the Moore language increases the likelihood of labor force participation by 36 percent, with a strong impact on women at 59 percent, nine times higher than men, and 38.3 percent for rural individuals, five times higher than individuals living in urban areas. The Dioula language exhibits comparable trends, while Fulfulde has a negative impact on individuals. The study recommends the use of local language(s) as official language(s) to improve labor force participation. However, a bilingual approach combining local and international language(s) will be of use to account for globalization and international competitiveness. The findings here may be of use to researchers and policymakers as part of their effort to increase the labor force participation rates of women and rural individuals. Moreover, this research has significant implications with regard to the implementation of language use policies in a variety of postcolonial language contexts.

피랍 민간항공기에 대한 무력행사의 한계에 관한 연구 (A Study on the Limits in the Use of Force against a Hijacked Civil Aircraft)

  • 김만호
    • 항공우주정책ㆍ법학회지
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    • 제19권1호
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    • pp.141-163
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    • 2004
  • 영공을 침범한 민간항공기에 대한 무력행사의 한계에 대해서는 국제법상 정립되어 있지 아니하다. 따라서 본 논문에서는 민간항공기의 영공침범에 관련된 국제법과 국제관행을 살펴보고, 특히 정치적 테러 수단으로 피랍된 민간항공기에 대한 무력행사의 적법성을 고찰하고자 한다. 본 논문의 연구범위는 평시에 영공을 침범한 민간항공기에 대한 요격 문제에 한정하고 있으며, 국가항공기의 영공침범에 관한 문제나, 요격으로 인한 민형사상의 책임에 관한 문제는 배제하고 있다. 본 논문에서는 영공을 침범한 민간항공기에 관련된 현행 국제법규와 각국의 무력행사 사례들을 분석하므로써, 국제법과 국제관행상 용인되고 있는 무력행사의 요건들을 정립하고, 그것들을 정치적 테러수단으로 피랍된 민간항공기의 특별 사례에 적용하고 있다. 결론적으로, 본 논문에서는 영공을 침범한 민간항공기에 대한 무력행사의 요건으로서 필요성, 최후수단성, 비례성이라는 기본원칙을 제시하고 있으며, 정치적 테러수단으로 피랍된 민간항공기에 대한 무력행사의 가능성에 대해서는 당해 국가안전의 필요성이라는 요인 때문에 다른 어떠한 형태의 영공침범 민간항공기에 대한 것 보다도 높을 수 밖에 없음을 마지막으로 제시하고 있다.

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전륜 횡력의 포화를 고려한 ESC와 AFS의 통합 섀시 제어 (Integrated Chassis Control with Electronic Stability Control and Active Front Steering under Saturation of Front Lateral Tire Forces)

  • 임성진
    • 제어로봇시스템학회논문지
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    • 제21권10호
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    • pp.903-909
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    • 2015
  • This article presents an integrated chassis control with electronic stability control (ESC) and active front steering (AFS) under saturation of front lateral tire force. Regardless of the use of AFS, the front lateral tire forces can be easily saturated. Under the saturated front lateral tire force, AFS cannot be effective to generate a control yaw moment needed for the integrated chassis control. In this paper, new integrated chassis control is proposed in order to limit the use of AFS in case the front lateral tire force is saturated. Weighed pseudo-inverse control allocation (WPCA) with variable weight is adopted to adaptively use the AFS. To check the effectiveness of the proposed scheme, simulation is performed on a vehicle simulation package, CarSim. From simulation, the proposed integrated chassis control is effective for vehicle stability control under saturated front lateral tire force.

정보기술을 적용한 무기체계의 적기 전력화 방안 (Timely Force Integration Method for Weapon System Using the Intelligence Technology)

  • 양병희
    • 한국국방경영분석학회지
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    • 제29권2호
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    • pp.131-147
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    • 2003
  • The complexity of modern weapon systems using the intelligence technology demands that rapid and effective transition from force requirements to deployment and fielding. Thus this paper deals with the integration of development procedure, evolutionary acquisition, integrated test and evaluation, improvement of the requirements decision process, use of commercial products of high quality and low cost, specification deviation, and the effective use of dual use technology. In general, decision­makers, and military field users shall first consider the moving technology rapidly into use. This study is aimed to improve the defence acquisition management directive for timely force integration of weapon system.

일점전개함수에 의한 Heteronuclear Diatomic Molecules의 Force Constants의 계산 II. Cubic Force Constants (Calculation of the Force Constants of Heteronuclear Diatomic Molecules by Use One Center Function. Ⅱ. Cubic Force Constants)

  • 김호징;김희준
    • 대한화학회지
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    • 제16권5호
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    • pp.261-264
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    • 1972
  • LiH, BeH, BH, CH, NH 및 OH 등의 heteronuclear diatomic molecules의 quadratic force constants를 Bishop등의 일점전개함수에 의하여 계산하였다. 계산의 master formula는 본 저자들 중의 한 사람에 의하여 이미 제안된 바 있다. 계산 결과는 실험치와 잘 일치하였다. 일점전개함수의 전개중심에 가까이 위치하고 있는 원자핵의 주위에서의 전자분포는 실제에서 비교적 벗어나며, $P_2(cos{\theta})/r^3$의 전개 중심을 이 원자핵에 잡으면 제안된 식으로부터 그릇된 결과가 얻어지는 것을 발견하였다

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일점전개함수에 의한 Heteronuclear Diatomic Molecules의 Force Constants의 계산. Ⅰ. Quadratic Force Constants (Calculation of the Force Constants of Heteronuclear Diatomic Molecules by Use of One Center Function. Ⅰ. Quadratic Force Constants)

  • 김호징;김희준
    • 대한화학회지
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    • 제16권4호
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    • pp.214-218
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    • 1972
  • The quadratic force constants of heteronuclear diatomic molecules, LiH, BeH, BH, CH, NH and OH are evaluated by use of the one center function of Bishop et. al. The master formula on which the computation is based was suggested by the previous work of one of the present authors. The results are in good agreement with the experimental values. It is found that around the nucleus of the atom located in the close vicinity of the expansion center of the one center function, the electronic distribution is relatively unrealistic, and the suggested formula would lead an erroneous result when one takes the origin of variables of $P_2(cos{\theta})/r_3$ at the atomic nucleus.

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Force control of an asymmetric hydraulic cylinder for active suspensions

  • Kim, Wanil;Lee, Byung-Youn;Won, Sang-Chul
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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    • pp.1124-1127
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    • 1996
  • Asymmetric cylinders are usually used as an actuator of active suspensions. Since the force is influenced not only by the control but by the road roughness, force control is needed to track the desired force. But the conventional error feedback control treats the valve-cylinder dynamics at its operating point and many use the symmetric model which differ in all respects. We adopt an asymmetric cylinder model and apply a feedback linearization method for the force control to compensate both the valve nonlinearities and the effects of the road roughness.

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The effect of resin cements and primer on retentive force of zirconia copings bonded to zirconia abutments with insufficient retention

  • Kim, Seung-Mi;Yoon, Ji-Young;Lee, Myung-Hyun;Oh, Nam-Sik
    • The Journal of Advanced Prosthodontics
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    • 제5권2호
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    • pp.198-203
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    • 2013
  • PURPOSE. The purpose of this study was to investigate the effect of resin cements and primer on the retentive force of zirconia copings bonded to zirconia abutments with insufficient retention. MATERIALS AND METHODS. Zirconia blocks (Lava, 3M ESPE, St. Paul, MN, USA) were obtained and forty sets of zirconia abutments and copings were fabricated using CAD/CAM technology. They were grouped into 4 categories as follows, depending on the types of resin cements used, and whether the primer is applied or not:Panavia F2.0 (P), Panavia F2.0 using Primer (PRIME Plus, Bisco Inc, Schaumburg, IL, USA) (PZ), Superbond C&B (S), and Superbond C&B using Primer (SZ). For each of the groups, the cementation was conducted. The specimens were kept in sterilized water ($37^{\circ}C$) for 24 hours. Retentive forces were tested and measured, and a statistical analysis was carried out. The nature of failure was recorded. RESULTS. The means and standard deviations of retentive force in Newton for each group were $265.15{\pm}35.04$ N (P), $318.21{\pm}22.24$ N (PZ), $445.13{\pm}78.54$ N (S) and $508.21{\pm}79.48$ N (SZ). Superbond C&B groups (S & SZ) showed significantly higher retentive force than Panavia F2.0 groups (P & PZ). In Panavia F2.0 groups, the use of primer was found to contribute to the increase of retentive force. On the other hand, in Superbond C&B groups, the use of primer did not influence the retention forces. Adhesive failure was observed in all groups. CONCLUSION. This study suggests that cementation of the zirconia abutments and zirconia copings with Superbond C&B have a higher retentive force than Panavia F2.0. When using Panavia F2.0, the use of primer increases the retentive force.