• Title/Summary/Keyword: Continuous Relaxation

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A Study on Inventory Control Policy for Quantity-Discount and Budget Constraint (수량 할인과 예산 제약을 고려한 재고관리 정책에 관한 연구)

  • Lee, Dongju
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.38 no.2
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    • pp.145-151
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    • 2015
  • As order quantity is increased, the ordering cost per item will be cheaper due to saving of transportation and material handling costs. In this paper, two realistic assumptions such as quantity discount and budget limit are considered. Quantity discount means that all units in the order will be discounted according to the predetermined order levels. Budget limit represents that the costs for inventory investments are bounded. This paper develops a Lagrangian relaxation approach for a continuous review inventory model with a budget constraint and quantity discounts. Computational results indicate that the proposed approach provides a good solution. Sensitivity analysis is done to get some insights on budget limit and quantity discount. As budget limit or the amount of discount according to order quantity is increased, order quantity is increased, whereas reorder point is not always increased.

The Impact of Singing Bowl Healing on the Autonomic Nervous System and Brainwaves (싱잉볼 힐링이 자율신경계 반응과 뇌파에 미치는 영향)

  • Youn-Kyung Jun;Geo-Lyong Lee
    • Science of Emotion and Sensibility
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    • v.26 no.4
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    • pp.125-132
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    • 2023
  • This study investigated the effects of continuous Singing Bowl healing on brainwaves and autonomic nervous system responses. The variations in brainwaves were measured during 45-minute sessions in eight participants, before and after Singing Bowl healing sessions to assess the changes in brainwaves before and after five weeks of Singing Bowl healing treatment. BioBrain BIOS-S8 was used to obtain brainwave measurements. Electrodes were placed on six channels: F3, F4, T3, T4, P3, and P4. A standard limb lead I with electrodes was used for electrocardiogram (ECG) measurements. Using the collected brainwave data, changes in brain waves were observed before and after five weeks of Singing Bowl healing. Beta waves, alpha waves, and sensorimotor rhythm were found to have reduced, while theta waves, delta waves, and the standard deviation of normal-to-normal intervals in heart rate variability had increased. These results indicate that continuous Singing Bowl healing over five weeks can stabilize brainwaves, activate the autonomic nervous system, and increase the relaxation-inducing effects of the parasympathetic nervous system.

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The Experimental Study of the Effects of Continuous Traction Therapy in Meridian Sinews Therapy (경근 치료방법 중 지속적 견인요법의 효과에 관한 실험적 연구)

  • Shin, Jeong-Hun;Hwang, Sung-Yeoun;Keum, Kyung-Soo;Kim, Jae-Hyo;Sohn, In-Chul;Ahn, Seong-Hun
    • Korean Journal of Acupuncture
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    • v.29 no.3
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    • pp.385-395
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    • 2012
  • Objectives : Meridian sinew theory was introduced in Miraculous Pivot, Huangdi's Internal Classic, to explain in relation with locations of meridian sinews, causes, mechanisms, and treatment of diseases. The meridian sinews are understood to include muscles, tendons and ligaments, or muscles in the superficial body made up with muscles, ligaments, tendons, fascia etc. This theory shows the similarity or organic relationship between the meridian sinews and muscles. From the Hippocrates(460-385 BC) ages, traction therapy was used as a treatment method on muscular diseases such as low back pain, scoliosis, etc in western medicine. The effects of traction therapy, however, were unclear so that this study was purposed to illustrate the effectiveness of continuous traction therapy and to develop meridian sinews treatment. Methods : We made 2 hypotheses to explain the cause of scoliosis occurrence, muscles contraction and relaxation. As the hypothesis, we made the spinal model having 3 joints with wood and rubber bands. Each of the three joints in the spinal model represents the case of normal(NT; control), contraction(AT 1)and relaxation(AT 2) condition, and distance between the vertebrae joints was measured. Results : Under normal circumstance models, the normal type 1(NT 1; muscle relax state) and normal type 2(NT 2; muscle contract state) all joints were being towed equally. But in an unusual contracted situation, regardless of the relationship of joint area, contracted part of joint was not released. And in a relaxed situation, regardless of joint areas, released parts of joint were further released. These observation results mean that the effects of traction might be different from the purpose of traction therapy of Hippocrates. Conclusions : To explain the effect of traction therapy for scoliosis, the spinal cord model and scoliosis model were made. After vertebral bodies were pulled with different tensile forces, we compared the observed length of the each joints pulled. The results suggested that there were no effects of traction in objected parts with traction method from Hippocrates' design, continuous traction method. Moreover, it may worsen the symptom in worst case. Of course, our results are just the result of experimental models and clinical results may be different. More careful studies, therefore, are required.

Structural analysis of cracked R.C. members subjected to sustained loads and imposed deformations

  • Mola, F.;Gatti, M.C.;Meda, G.
    • Structural Engineering and Mechanics
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    • v.11 no.6
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    • pp.637-650
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    • 2001
  • A structural analysis of cracked R.C. members under instantaneous or sustained loads and imposed displacements is presented. In the first part of the paper the problem of deriving feasible moment-curvature diagrams for a long term analysis of R.C. sections is approached in an exact way by using the Reduced Relaxation Function Method in state I uncracked and the method suggested by CEB in state II cracked. In both states the analysis of the main parameters governing the problem has shown that it is possible to describe the concrete creep behaviour in an approximate way by using the algebraic formulation connected to the Effective Modulus Method. In this way the calculations become quite simple and can be applied in design practice without introducing significant errors. Referring to continuous beams, the structural analysis is then approached in a general way, applying the Force Method and the Principle of Virtual Works. Finally, considering single members, the structural analysis is performed by means of a graphical procedure based on the application of feasible moment-rotation diagrams which allow to easily solve various structural problems and to point out the most interesting aspects of the long term behaviour of cracked R.C. members with rigid or elastically deformable redundant restraints.

A Viscoelastic Study of Glass Transition and Degradation Processes of Phenolic Resin/Carbon Fiber Composites (페놀수지/탄소섬유 열경화성 복합재료의 유리전이와 고온 분해과정에서 관찰되는 점탄성 특성 연구)

  • ;J. C. Seferis
    • The Korean Journal of Rheology
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    • v.11 no.1
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    • pp.9-17
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    • 1999
  • Viscoelastic characteristics of cured phenolic resin/carbon fiber composite materials were investigated through glass transition and degradation reaction processes in the high temperature region up to $400^{\circ}C$. A typical glass transition of the cross-linked thermoset polymer was followed by irreversible degradation reactions, which were exhibited by the increasing storage modulus and loss modulus peak. A degradation master curve was constructed by using the vertical and horizontal shift factors, both of which complied well with the Arrhenius equation in light of the kinetic expression of degradation rate constants. Using an analogy to the Havriliak-Negami equation in dielectric relaxation phenomena, a viscoelastic modeling methodology was developed to characterize the frequency- and temperature-dependent complex moduli of the degrading thermoset polymer composite systems. The temperature-dependent relaxation time of the degrading composites was determined in a continuous fashion and showed a minimum relaxation time between the glass transition and degradation reaction regions. The capability of the developed modeling methodology was demonstrated by describing the complex behavior of the viscoelastic complex moduli of reacting phenolic resin composite systems.

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Real-time Observation of Evolution Dynamics of Ge Nanostructures on Si Surfaces by Photoelectron Emission Microscopy (자외선 광여기 전자현미경을 이용한 Si 표면 위에 Ge 나노구조의 성장 동역학에 관한 실시간 연구)

  • Cho, W.S.;Yang, W.C.;Himmerlich, M.;Nemanich, R.J.
    • Journal of the Korean Vacuum Society
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    • v.16 no.2
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    • pp.145-152
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    • 2007
  • The evolution dynamics of nanoscale Ge islands on both Si (001) and (113) surfaces is explored using ultraviolet photoelectron emission microscopy (UV-PEEM). Real-time monitoring of the in-situ growth of the Ge island structures can allow us to study the variation of the size, the shape and the density of the nanostructures. For Ge depositions greater than ${\sim}4$ monolayer (ML) with a growth rate of ${\sim}0.4\;ML/min$ at temperatures of $450-550^{\circ}C$, we observed island nucleation on both surfaces indicating the transition from strained layer to island structure. During continuous deposition the circular islands grew larger via ripening processes. AFM measurements showed that the islands grown on Si (001) were dome-shaped while the islands on Si (113) were multiple-side faceted with flat tops of (113)-orientation. In contrast, for Ge deposition with a lower growth rate of ${\sim}0.15\;ML/min$ on Si(113), we observed the shape transition from circular into elongated island structures. The elongated islands grew longer along the [$33\bar{2}$] during continuous Ge deposition. The shape evolution of the islands is discussed in terms of strain relaxation and kinetic effects.

Immediate Effect of Intermittent Versus Continuous Hamstring Static Stretching on the Muscle Tone and Range of Motion

  • Chen, Jin-Gyi;Choi, Eun-Hong;Kim, Myoung-Kwon
    • Journal of the Korean Society of Physical Medicine
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    • v.14 no.4
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    • pp.19-27
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    • 2019
  • PURPOSE: This study examined which stretching exercise had the most positive effect on increasing the range of motion (ROM) of the knee joint in healthy people and whether there was a difference between continuous stretching and intermittent stretching. METHODS: This study included 30 healthy university students from OOO University. The subjects were asked to sit on a mat and perform hamstring-stretching exercise during which the ROM and muscle tone were measured with pre and post-tests. Each subject was assigned randomly to a continuous stretching group (stretching without relaxation time group, n=10, G1) or intermittent stretching group (stretching with 10s relaxing time group, n=10, G2; and stretching with 20s relaxing time group, n=10, G3). The participants conducted hamstring stretching exercises with a sit-and-reach box at three different rest times (0s, 10s, and 20s). Subsequently, they underwent passive knee extension (PKE) tests, in which the ROM of the knee joint was measured with a goniometer, and the muscle tone was evaluated using a MyotonPro. RESULTS: Significant differences in muscle tone, stiffness, and ROM were observed between pre-test and post-test in each groups (p<.05). Although the post hoc tests indicated no significant differences in muscle tone and ROM between the continuous stretching group and intermittent stretching group (p>.05), the rate of change of the ROM showed that the intermittent stretching group developed more effective maintenance of the hamstring flexibility. CONCLUSION: No significant differences in the muscle tone of the hamstring and ROM of the knee joint were observed according to the hamstring stretching exercises with three different rest times. On the other hand, the rate of change of the ROM showed that intermittent stretching maintained the hamstring flexibility more effectively.

The Effect of Motivation and User Characteristics on Use Satisfaction and Continuous Use Intention in YouTube Vlog (유튜브 브이로그 이용 동기 및 이용자 특성이 이용 만족 및 지속이용의도에 미치는 영향)

  • Youn, Ji-Young;Yoo, Ji-Yoon;Lee, Jang-Suk
    • The Journal of the Korea Contents Association
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    • v.20 no.4
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    • pp.189-201
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    • 2020
  • As communicating with friends by recording their daily lives in video clips has become a trend for the Z-generation or the Millennial generation, interest in the vlog is increasing. This study analyzed the effects of motivation and user characteristics on use satisfaction and intention to use vlog in 168 participants in their 20s and 30s who have experience using YouTube vlog. The results of the study showed all hypotheses established in this study were adopted. Specifically, habits and killing time, information-seeking, entertainment and relaxation, voyeurism, openness and emotional identification were found to have a positive effect on the use satisfaction. Also, satisfaction with the use of vlog has a significant impact on continuous use intention. Therefore, it can be seen that exploring the vlog will provide theoretical and practical implications.

Document Summarization via Convex-Concave Programming

  • Kim, Minyoung
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.16 no.4
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    • pp.293-298
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    • 2016
  • Document summarization is an important task in various areas where the goal is to select a few the most descriptive sentences from a given document as a succinct summary. Even without training data of human labeled summaries, there has been several interesting existing work in the literature that yields reasonable performance. In this paper, within the same unsupervised learning setup, we propose a more principled learning framework for the document summarization task. Specifically we formulate an optimization problem that expresses the requirements of both faithful preservation of the document contents and the summary length constraint. We circumvent the difficult integer programming originating from binary sentence selection via continuous relaxation and the low entropy penalization. We also suggest an efficient convex-concave optimization solver algorithm that guarantees to improve the original objective at every iteration. For several document datasets, we demonstrate that the proposed learning algorithm significantly outperforms the existing approaches.

Development of Analysis System for Sheet Metal Forming (박판금속 성형공정 해석시스템 개발)

  • 정완진;조진우
    • Transactions of Materials Processing
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    • v.8 no.1
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    • pp.29-37
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    • 1999
  • An analysis system for sheet metal forming(SAT_STAMP) has been developed to improve the design and tryout process by predicting the deformation behavior more precisely. This analysis system consists of forming analysis, springback analysis and post processor modules. The more accurate prediction of stress history can be achieved due to the improved contact algorithm. Continuous simulation of sequential processes can be carried out conveniently without interruption by the improved data management of the developed system. The error of data transfer between forming analysis and springback analysis is minimized using the proper shell element. Several benchmark test results and practical results are presented to show the effectiveness and reliability of this program.

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