• Title/Summary/Keyword: 탄성안정

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Representation of Curl Exaggeration, Cohesion, Adhesion and Stiffness in Wet Curly Hair

  • Jong-Hyun Kim
    • Journal of the Korea Society of Computer and Information
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    • v.28 no.10
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    • pp.77-84
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    • 2023
  • Simulating the cohesion and stiffness of wet hair or fur in physics-based simulations is one of the most challenging problems. Wet hair or fur is characterized by bunching and stiffening at the ends, a phenomenon that can be seen in wet animal fur or hair. In addition, when wet hair interacts with a solid, adhesion occurs, but this problem becomes difficult to solve due to the different distribution and balance of forces in curly hair. In traditional methods, wet hair is represented by hand or by using static hairstyles to represent wet curls and hair. However, how to depict the details of wet curly hair has not been actively researched. In this paper, we propose a new algorithm to efficiently model the curl exaggeration, cohesion, adhesion, and stiffness of wet curly hair. The proposed method efficiently simulates cohesion and integrates stiffness constraints with curl dynamics to reliably control hair elasticity.

Effect of Sling-Applied Plank Exercise on the Muscular Frequency, Stiffness, Decrement of the Rectus Abdominis and Longissimus of the Trunk according to the Stability of the Base of Support (지지면의 안정성에 따른 슬링적용 플랭크 운동이 몸통 배곧은근과 가장긴근의 근긴장도, 근경직도, 근탄성도에 미치는 영향)

  • Jung-Gyu Yoon
    • PNF and Movement
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    • v.22 no.2
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    • pp.181-189
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    • 2024
  • Purpose: This study aimed to identify the effect of sling-applied plank exercise on the frequency, stiffness, and decrement of the rectus abdominis and longissimus muscles of the trunk according to the stability of the base of support. Methods: Thirty-three young adults volunteered to participate and were randomly assigned to one of three groups (SS, stable support; LES, lower extremity support; and ULES, upper and lower extremity support) according to the stability of the base of support. The muscular properties of the rectus abdominis and longissimus muscles during sling-assisted plank exercise according to the stability of the base of support. were measured by using Myoton PRO (Myoton AS, Tallinn, Estonia). Statistical analysis was performed MANOVA to determine the effect of sling-assisted plank exercise on the muscular properties of the rectus abdominis and longissimus muscles according to the stability of the base of support. Post hoc analysis was conducted using Bonferroni. The level of statistical significance was set at α = 0.05. Results: When comparing the muscular properties, the muscle frequency and stiffness of the left rectus abdominis of ULES were significantly decreased compared to that of SS (p < 0.05). In the measurement time, the muscle frequency and the muscle stiffness of the right rectus abdominis increased significantly after the intervention (p < 0.05). Conclusion: It was concluded that the more unstable the base of support (ULES), the higher the exercise strength, and the muscle frequency and stiffness decreased on the rectus abdominis at rest.

Quality stability of vinegar pickled sardine during storage (정어리 초절임제품의 저장중 품질안정성)

  • Lee, Eung-Ho;Lee, Jeong-Suk;Kim, Jin-Soo;Oh, Kwang-Soo;Cho, Soon-Yeong
    • Applied Biological Chemistry
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    • v.36 no.5
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    • pp.346-351
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    • 1993
  • In present paper, we examined the quality stability of vinegar pickled sardine during storage. The moisture content of all samples showed a little change, while pH and volatile basic nitrogen content of pickled sardine processed with vinegar seasoning solution mixed antioxidants increased during storage at ambient temperature. The viable cell counts and histamine content of vinegar pickled sardine increased very standingly during storage at ambient temperature, while increased vely slowly during cold storage. The thiobarbituric acid value and peroxide value of vinegar pickled sardine prepared without antioxidants increased up to 60 days and then decreased during cold storage. In case of changes in fatty acid composition of vinegar pickled sardine prepared without antioxidants during cold, percentage of polyenes such as 20 : 5 and 22 : 6 decreased. In case of the results for texture profile analysis of vinegar pickled sardine treated with antioxidants during storage at ambient temperature, the hardness and toughness decreased, while the cohesiveness and elasticity showed a little changes. Judging from the results of chemical and sensory evaluation, the product B, sardine pickled in vinegar seasoning solution mixed with antioxidants could be keeped on freshness and retarded on lipid oxidation until 90 days during storage at $5^{\circ}C$.

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Uplift Testing and Load-transfer Characteristics of Model Drilled Shafts in Compacted Weathered Granite Soils (화강풍화토 지반에 타설된 소형 현장 타설 말뚝의 인발시험 및 하중 전이 특성)

  • 임유진;서석현
    • Journal of the Korean Geotechnical Society
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    • v.18 no.4
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    • pp.105-117
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    • 2002
  • In the design of foundations for the super-structures such as transmission towers and oil-platforms, the foundations must be considered as a medium to resist cyclic tensile forces. In this study, the uplift capacity of the drilled shaft used as the medium resisting to this pattern of forces is investigated by performing cyclic uplift test of a small model-drilled shaft constructed in compacted granite soil in a steel chamber. In this test, the behavioral difference between a pile loaded on the top of the pile and a pile loaded at the bottom of the pile was investigated intensively. The load transfer curves obtained from the test were investigated by changing the confining pressure in the chamber. The load tests also included creep test and cyclic test. It is found from the tests that uplift capacity of the shaft loaded at the bottom is greater than that of the shaft loaded on the top of the pile. It is found also from the creep test that the pile loaded at the bottom was more stable than the shaft loaded on the top. If a pile loaded at the bottom is pre-tensioned, the pile will be most effective to the creep displacement. It is found also from the cyclic tests that apparent secant modulus obtained in a cycle of the load increases with the number of cycles.

Preparation and Keeping Quality of Canned Liquid Smoked Oyster Products (훈액처리에 의한 굴 통조림의 품질개선에 관한 연구)

  • LEE Eung-Ho;CHO Soon-Yeong;CHUNG Su-Yeol;CHA Yong-Jun
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.16 no.1
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    • pp.1-7
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    • 1983
  • In order to improve the quality of canned oyster, canned oyster in oil as control, canned smoked oyster in oil and canned liquid smoked oyster in oil were prepared, and the masking effect of green meat and the stability of their qualities during storage were examined. Three kinds of canned oyster products showed little change in pH, VBN and TBA during 4 months storage in room temperature. In texture of the products, however, hardness and toughness of all the products decreased slightly after 3 months storage, while elasticity and cohesiveness did not change largely up to 4 months storage. Green meat appeared on the surface of canned oyster in oil as control after 30 days storage. And the masking of green meat could be achieved more effectively by dipping treatment of meat for 30 seconds in smoke flavor(Smoke-EZ, Alpha Foods Co., Ltd.) solution than conventional smoking process.

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Evaluation of the Cytotoxicity and Mechanical Strength of Dental Duplex Stainless Steel Orthodontic Wire (치과 교정용 듀플렉스 스테인리스 스틸 와이어의 기계적 강도 및 세포독성 평가)

  • Lee, Myung-Kon;Kim, Chi-Young
    • The Journal of the Korea Contents Association
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    • v.10 no.9
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    • pp.309-317
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    • 2010
  • The stainless steel wire is extensively used for the orthodontic treatment. But, the stainless steel wire that has commonly superior corrosion resistance has caused hypersensitive reaction or allergy as side effects because of corrosion in the oral environment. For improving the problem of corrosion, we was evaluated the suitability of the duplex stainless steel(DSS) as orthodontic wire through this study. The DSS wire was evaluated the mechanical strength and bio-stability for suitability and bio-compatibility as orthodontic wire. In this work, the DSS and stainless steel(SS) as common use of medical grade were prepared for the tensile strength test. The DSS wire were treated by heat. and Temperature conditions of the heat treatment were $28^{\circ}C$, $500^{\circ}C$, $600^{\circ}C$, $700^{\circ}C$, $800^{\circ}C$, $900^{\circ}C$, respectively. And the DSS wires that treated by heat on the optimum temperature condition were conducted the bending moment test and calculated the S-Max value and the modulus of elasticity. For evaluating the bio stability, each materials were conducted in vitro test for measuring the cell survival rate. The most interesting results was that the tensile strength test of SS wire($8.17\times10^4\;N/mm^2$) and DSS wire($8.05\times10^4\;N/mm^2$) that treated at $500^{\circ}C$ by heat were similar in mechanical strength. In the bio-stability study, the DSS has no cytotoxicity (p=0.05) Thus, we could make a conclusion that the duplex stainless steel wire has vastly superior corrosion resistance was suitable as orthodontic wire.

Physical Property of W-C-N Diffusion Barrier through Stress-Strain curve (Stress-Strain curve를 이용한 W-C-N 확산방지막 물성 특성 연구)

  • Lee, Kyu-Young;Kim, Soo-In;Park, Sang-Jae;Lee, Dong-Kwan;Jeong, Yong-Rok;Jung, Jun;Lee, Jong-Rim;Lee, Chang-Woo
    • Journal of the Korean Vacuum Society
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    • v.20 no.4
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    • pp.266-270
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    • 2011
  • This paper suggest tungsten (W)-carbon (C)-nitrogen (N) thin films for diffusion barrier that W is main material and C and N are additives. W-C-N thin films are deposited with fixed rates of W and C but with a variation of $N_2$ gas flow and W-C-N thin films are heated at $600^{\circ}C$. From the experimental results, the variation of elastoplastic region for W-C-N thin film measured by tribological property is larger than that of elastic region with a variation of $N_2$ gas flow. These results show that the $N_2$ gas flow is more directly related with the elastoplastic region of W-C-N thin film. Nanoindenting test executed 16 times consecutively and we got the stress-strain curve graphs and hardness datas at each sample. Through the stress-strain curve graphs, the standard diviation of stress-strain curve for $N_2$ gas flow rate of 2.0 sccm is smaller than that of 0, 0.5, 1.5 sccm. Consequently, the physical stability of W-C-N thin film depends on the flow rate of $N_2$ gas.

Coupled Finite Element Analysis of Partially Saturated Soil Slope Stability (유한요소 연계해석을 이용한 불포화 토사사면 안전성 평가)

  • Kim, Jae-Hong;Lim, Jae-Seong;Park, Seong-Wan
    • Journal of the Korean Geotechnical Society
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    • v.30 no.4
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    • pp.35-45
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    • 2014
  • Limit equilibrium methods of slope stability analysis have been widely adopted mainly due to their simplicity and applicability. However, the conventional methods may not give reliable and convincing results for various geological conditions such as nonhomogeneous and anisotropic soils. Also, they do not take into account soil slope history nor the initial state of stress, for example excavation or fill placement. In contrast to the limit equilibrium analysis, the analysis of deformation and stress distribution by finite element method can deal with the complex loading sequence and the growth of inelastic zone with time. This paper proposes a technique to determine the critical slip surface as well as to calculate the factor of safety for shallow failure on partially saturated soil slope. Based on the effective stress field in finite element analysis, all stresses are estimated at each Gaussian point of elements. The search strategy for a noncircular critical slip surface along weak points is appropriate for rainfall-induced shallow slope failure. The change of unit weight by seepage force has an effect on the horizontal and vertical displacements on the soil slope. The Drucker-Prager failure criterion was adopted for stress-strain relation to calculate coupling hydraulic and mechanical behavior of the partially saturated soil slope.

Evaluation of Loss of Prestress Force of Tensile Anchor by Long Term Measurement (장기계측을 통한 인장형 앵커의 인장력 손실 평가)

  • Lee, Bongjik;Lee, Jongkyu
    • Journal of the Korean GEO-environmental Society
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    • v.16 no.10
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    • pp.15-22
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    • 2015
  • In this study, to evaluate the long-term behavior characteristics and the loss of prestress force, the long-term measurement of the tensile anchors in the actual construction was performed and the results were analyzed comparing with the existing estimation. As the reinforcement member used for the purpose of slope stability or uplift-resisting of the permanent structure, etc, the permanent anchor should maintain the functions during the performance period of the structure differently from the temporary anchor. However, as the time passes by, since the relaxation and the creep of the anchor occur constantly, the management for the loss of tensile force is essential to perform the functions stably. So far, the loss of the tensile force has been estimated according to the reduction of the prestress using elasticity theory and using the relaxation value according to the type of tension member and the test using the long-term measurement is limited. Therefore, in this study, the site condition and the ground were investigated for the tensile anchor in the actual construction and the long-term measurement results more than 500 days was analyzed by installing the loadcell, inclinometer and the groundwater level gauge. In addition, the long-term behavior characteristics were evaluated by comparing the disposition of the measured earth retaining wall and the tension force loss of the anchor with the existing interpretation results. In the evaluation results, the most of the tension force loss occurs within 90 days and the loss was measured less than the estimated values.

우리나라 수입함수추정(輸入函數推定)에 있어서 수입단가(輸入單價)와 수입물가(輸入物價)의 비교(比較)

  • Yu, Yun-Ha
    • KDI Journal of Economic Policy
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    • v.17 no.3
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    • pp.3-54
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    • 1995
  • 외환(外換) 및 자본자유화(資本自由化)의 진전에 따라 환율(換率)의 변동폭이 커지면서 환율(換率)이 국제수지(國際收支)에 미치는 영향에 대한 관심이 높아지고 있다. 환율(換率)이 국제수지(國際收支)에 미치는 효과는 일차적으로 우리나라 수출입함수(輸出入函數)의 가격탄력성(價格彈力性)에 의해 결정되므로 정확한 탄성치(彈性値)를 추정하는 일은 이론적으로나 정책적으로 매우 중요한 의미를 갖는다. 본고에서는 우리나라 수입함수(輸入函數)의 소득(所得) 및 가격탄성치(價格彈性値) 추정에 있어서 사용 가능한 두가지의 가격지수(價格指數), 즉 수입단가(輸入單價)와 수입물가(輸入物價) 중 어느 것을 사용하는 것이 바람직한 것인지를 살펴보고 이중 이론적으로 우월한 지수를 이용하여 수입함수(輸入函數)의 소득(所得) 및 가격탄성치(價格彈性値)를 추정하고자 하였다. 분석으로부터 얻는 중요한 결론(結論)은, 우리나라의 경우 수입함수(輸入函數)의 분석에 있어서 수입단가(輸入單價)보다는 수입물가(輸入物價)를 이용하는 것이 더 적합하리라는 점이다. 이는 또한 우리나라 실질(實質)GNP의 추계에 있어서 현재의 수입단가(輸入單價) 이용방식에서 수입물가(輸入物價) 이용방식으로 편제방법을 바꾸는 것이 바람직하다는 것을 의미한다. 이같은 결론은 이론적, 실증적인 변에서 아래와 같은 네가지 이유에 근거한다. 먼저 이론적인 면에서는 첫째, 수입단가(輸入單價)가 물가지수(物價指數)로서 갖추어야 할 통계적 일관성을 갖추지 못하고 있다는 점을 지적할 수 있다. 즉 수입단가(輸入單價)는 어느 일정 규격조건(規格條件)의 상품가격(商品價格)을 일관성 있게 추적하는 것이 아니므로 잡다한 품질규격의 평균가격(平均價格)으로 나타날 가능성이 높으며 이러한 변에서 가격변화(價格變化)를 정확히 반영하지 못한다. 둘째, 수입단가지수(輸入單價指數)는 가격변화(價格變化)가 전혀 없을 때에도 총수입(總輸入)의 품목별 구성(構成)이 바뀌면 변동하는 속성을 지니고 있어 가격변동(價格變動) 상황(狀況)을 오도할 가능성을 지니고 있다. 다음으로 실증적인 면에서는 첫째, 수입단가(輸入單價)를 이용한 수입함수(輸入函數)에서는 가격변수(價格變數)의 계수(係數)가 이론상 기대되는 것과는 반대되는 부호를 가짐으로써 수입함수(輸入函數))로서의 기본적인 요건을 만족시키지 못하는 것으로 나타나고 있다. 둘째, 단가지수(單價指數)를 이용한 경우 소득(所得)과 상대가격(相對價格)을 회귀변수로 하는 수입함수(輸入函數)에서 장기안정적인 균충관계(均衝關係)가 존재하지 않은 것으로 판명되었다. 반면 수입물가(輸入物價)를 이용한 수입함수(輸入函數)에서는 각 변수의 계수(係數)가 이론적 기대치에 부합하였으며 장기안정적인 균충관계(均衝關係)가 성립하는 것으로 나타나고 있다. 한편 미국에서는 수출입단가지수(輸出入單價指數)의 문제점에 대한 오랜 연구 결과, 1989년부터 단가지수(單價指數)의 편제를 아예 중단하는 조치를 취한 바 있으며, GNP추계에 있어서도 종래의 수출입단가(輸出入單價) 대신 수출입물가(輸出入物價)를 이용하는 방식으로 그 편제방법을 변경한 바 있다.

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