• Journal of Welding and Joining
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• 제34권2호
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• pp.54-58
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• 2016

SPR(Self-Piercing rivet) is mechanical element of joining sheet metal components without the need for pre-punched or pre-drilled holes. Newly designed SPR is developed for high joining strength and shearing strength than semi-tubular rivet. In this study, divided shank of self-piercing rivet were designed for joining DP440 and SILAFONT. Newly designed SPR was simulated by using FEM code DEFORM-3D. In simulations of SPR process, various shape of self-piercing rivet were considered for semi-tubular and newly designed SPR. In other to examine the joinability, joining load and lap-shear load of newly designed SPR were compared with semi-tubular by simulated results and experimental ones.

• 한국기계가공학회지
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• 제8권3호
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• pp.74-81
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• 2009

At present, industries and researchers are looking for ways to reduce the use of lubricants because of ecological and economical reasons. Therefore, metal cutting is to move toward dry cutting or semi-dry cutting. One of the technologies is known as MQL machining. This paper presents an investigation into MQL machining with the objective of evaluating cylindricity and cooling effect for the turning process of SM45C. To reach this goal, cylindrical-outer-diameter turning experiments are carried out according to cutting conditions with fluid, MQL and dry machining methods. A cutting force, tool-shank temperature and cylindricity of workpiece are measured and analyzed. The correlation between cutting conditions and cylindricity are evaluated according to cooling lubricant environments.

• 한국연초학회지
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• 제16권1호
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• pp.57-64
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• 1994

Burley tobacco (Nicotiana tabacum L.) KB 108 was developed from a single cross between KB 104 and TC 591 which was developed from a cross between Burley 49 and Tobacco Introduction 1406. It was tested for its resistance to black shank, potato virus Y(PVY), TMV and agronomic characteristics under field conditions. KB 108 has resistance to tobacco mosaic virus(TMV) and necrotic strain of potato virus Y(PVY-VN) with secreting glandular trichomes. It has also moderate resistance to black shank caused by phytophthora parasitica val. Nicotianae. KB 108 has an up-right plant growth habit similar to Burley 21. It flowers about 1-2 days later than Burley 21. The leaf width and length of KB 108 are approximately 3 cm wider and longer than those of Burley 21. The yield of KB 108 was higher 4%, nearly equal in value per kg compared to Burley 21.

• 한국작물학회지
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• 제4권1호
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• pp.103-108
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• 1968

담배 각종병해저항성 품종육성의 기초자료를 얻기 위하여 우리나라 재래종에 대한 몇가지 병해에 대한 저항성검정을 하였다. (1) 역병에는 우방초, 오심엽초만이 중정도의 저항성이 있으며 수안초, 우설초, 광초 등이 그 다음이고 그 외품종은 모두 나병성이였다. DB 101, $H_2$, BY 4 등은 재래종보다 저항성이였다. (2) 흑근병에는 목기초, 우방초, 오심엽초가 중정도의 저항성이며 우설초, 수안초, 회초가 다음이며 향초는 BY 4만은 못하나 재래종중에서 가장 나병율이 높았다. (3) 야화병에는 대부분 나병율이 높은 편이나 흑초, 회초, 우방초가 약간 저항성이 인정되고 그 외품종은 거의 나병성이다. (4) 적성병에는 오심엽초가 고도의 저항을 엿보이며 우방초, 향초, 목기초 등이 중정도이고 광초, 우설초는 나병성이였다. 대조품종인 BY4나 Beinhart 1,000-1보다는 모두 나병율이 낮았다. (5) CMV-Y에 대하여서는 향초가 고도의 저항성이 인정되고 회초, 가자초가 저도이기는 하나 저항성이 있는 듯하다. (6) Blue mold병에 대에 하여는 공시품종 모두가 고도의 나병성임으로 이에 대한 저항성품종의 발굴이 절실히 요망된다.

• Steel and Composite Structures
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• 제42권3호
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• pp.407-426
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• 2022

Superior to traditional welded studs, high strength friction-grip bolted shear connectors facilitate the assembling and demounting of the composite members, which maximizes the potential for efficiency in the construction and retrofitting of new and old structures respectively. Hence, it is necessary to investigate the structural properties of high strength friction-grip bolts used in steel concrete composite beams. By means of push-out tests, an experimental study was conducted on post-installed high strength friction-grip bolts, considering the effects of different bolt size, concrete strength, bolt tensile strength and bolt pretension. The test results showed that bolt shear fracture was the dominant failure mode of all specimens. Based on the load-slip curves, uplifting curves and bolt tensile force curves between the precast concrete slab and steel beam obtained by push-out tests, the anti-slip performance of steel-concrete interface and shear behavior of bolt shank were studied, including the quantitative analysis of anti-slip load, and anti-slip stiffness, frictional coefficient, shear stiffness of bolt shank and ultimate shear capacity. Meanwhile, the interfacial anti-slip stiffness and shear stiffness of bolt shank were defined reasonably. In addition, a total of 56 push-out finite element models verified by the experimental results were also developed, and used to conduct parametric analyses for investigating the shear behavior of high-strength bolted shear connectors in steel-concrete composite beams. Finally, on ground of the test results and finite element simulation analysis, a new design formula for predicting shear capacity was proposed by nonlinear fitting, considering the bolt diameter, concrete strength and bolt tensile strength. Comparison of the calculated value from proposed formula and test results given in the relevant references indicated that the proposed formulas can give a reasonable prediction.

• BMB Reports
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• 제49권9호
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• pp.457-458
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• 2016

Recent studies have strongly implicated postsynaptic scaffolding proteins such as SAPAP3 or Shank3 in the pathogenesis of various mood disorders, including autism spectrum disorder, bipolar disorder (BD), and obsessive-compulsive disorders. Neural Abelson-related gene-binding protein 2 (nArgBP2) was originally identified as a protein that interacts with SAPAP3 and Shank3. Recent study shows that the genetic deletion of nArgBP2 in mice leads to manic/bipolar-like behavior resembling symptoms of BD. However, the function of nArgBP2 at synapse, or its connection with the synaptic dysfunctions, is completely unknown. This study provides compelling evidence that nArgBP2 regulates the spine morphogenesis through the activation of Rac1/WAVE/PAK/cofilin pathway, and that its ablation causes a robust and selective inhibition of excitatory synapse formation, by controlling actin dynamics. Our results revealed the underlying mechanism for the synaptic dysfunction caused by nArgBP2 downregulation that associates with analogous human BD. Moreover, since nArgBP2 interacts with key proteins involved in various neuropsychiatric disorders, our finding implies that nArgBP2 could function as a hub linking various etiological factors of different mood disorders.

• 한국축산식품학회지
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• 제37권2호
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• pp.313-319
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• 2017

This study was conducted to develop calcium-fortified shank bone extract (SBE) and to determine the effect of adding calcium lactate on physico-chemical characteristics of SBE during cold storage. The following five experiment groups were used: Control (0%, no addition), T1 (0.05% calcium lactate), T2 (0.1% calcium lactate), T3 (0.5% calcium lactate), and T4 (1% calcium lactate). When the concentration of calcium lactate added to the SBE was increased, the pH, redness, and yellowness values were significantly reduced, whereas the salinity, sugar content, and turbidity of SBE were significantly increased. Sensory parameters such as aroma, flavor, and overall acceptability in the control, T1, and T2 had similar scores. The TBARS values of SBE was significantly increased when 1% of calcium lactate was added, and the VBN values of SBE with calcium lactate at day 7 were higher than that of control (p<0.05). However, the addition of calcium lactate showed an inhibition effect on the growth of total microbial counts in SBE until 4 d of storage. The calcium content of SBE was increased by the addition of calcium lactate in a dose-dependently manner. The proper addition level of calcium lactate in the SBE was determined to be 0.1%.

• 한국운동역학회지
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• 제18권4호
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• pp.179-189
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• 2008

본 연구는 9명의 남자 중학교 초보피험자들을 대상으로 태권도 옆차기 동작의 숙련정도에 따른 운동학적 협응과정을 살펴보는 데 목적을 두었다. 이용된 변인은 최대합성직선속도, 분절간 각속도, 각도 대 각도 도면이었다. 분석결과, 연습후기로 갈수록 인접한 분절간의 운동량 전이가 잘 이루어져 각 분절의 최대합성직선속도가 유의하게 증가하였으며 분절간 각속도에서 학습후기로 갈수록 몸통에서 대퇴, 하퇴분절로의 순차적인 전이를 보였으며 던지는 듯하면서 미는 듯한 동작형태를 보였다. 엉덩관절과 무릎관절의 각도-각도 도면에서는 학습초기에는 다이나믹스한 변화를 보였으나 학습이 됨에 따라 숙련된 피험자처럼 안정적인 협응 패턴을 보여주었다.

• 한국운동역학회지
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• 제24권2호
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• pp.95-101
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• 2014

The purpose of this study was to investigate the training and detraining effects of a 8-week water exercise on lower extremities coordination during obstacle gait in the female elderly. Eight elderly participants (age: $76.58{\pm}4.97$ yrs, height: $148.88{\pm}7.19$ cm, body mass: $56.62{\pm}6.82$ kg, and leg length: $82.36{\pm}2.98$ cm), who stayed at the Seoul K welfare center, were recruited for this study. All participants had no history of orthopedic abnormality within the past 1 year and completed the aquatic exercise program which lasted for 8 weeks. To identify the training and detraining effect of 8 weeks of water exercise, a 3-D motion analysis with 7 infrared cameras and one force plate sampling frequency set at 100 Hz and 1,000 Hz, respectively, was performed. A two-way ANOVA was performed to find training and detraining effects among diferent obstacle heights. In this study significant level was set at .05. Significant training effects of LTS (lead foot thigh and shank) coordination in all obstacle height were found (p<.05). It is also found that the training effect of LTS remained 37%, 58%, and 25% in obstacle height of 30%, 40%, and 50%, respectively. Lead foot showed the greater detraining effect of coordination compared with trail foot, and SF (shank and foot) coordination revealed better detraining effects of coordination compare with TS (thigh and shank) in both feet. Based on the findings, a 8 week water exercise give an positive effects to the elderly in terms of segment cooperation which potentially helps reducing their accident falls. The magnitude of detraining may also help the elderly to find the retraining moment.

• 수산해양기술연구
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• 제31권3호
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• pp.240-246
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• 1995

옥돔의 조획 기구를 알아내고, 낚시를 개량하기 위해서 수조 중에서 옥돔의 연승어구에 대해 반응 행동을 비디오 카메라로 관찰 조사하였다. 옥돔은 물살을 거슬르면서 해저 위를 천천히 유영하며 미끼에 접근하였고, 미끼를 물때에는 불완전하게 무는 경우가 많았으며, 미끼를 문 후에는 천천히 뒤로 유영하면서 아릿줄이 당겨지면 미끼를 내뱉는 등의 완만하고 주의 깊은 행동을 보였다. 대부분의 조획은 미끼를 깊이 삼킨 후에 옥돔이 Rush 또는 Jerk 행동을 할 때 되었고, 조획과 관계 깊은 행동연쇄는 Chewing$\longrightarrow$Jerk 또는 Chewing$\longrightarrow$Rush였다. 현장시험에서 채가 긴 낚시가 조획성능이 매우 낮았고, 채가 짧은 낚시에는 조획성능도 양호하고 조획된 부위가 깊었던 것을 고려하면 옥돔은 낚시를 깊이 삼켜야만 조획이 가능하므로 조획성능만을 생각하면 낚시의 형상은 낚시 채가 짧으며 끝이 안으로 굽어 있는 형상이 적합하다. 본 연구에서 제안하는 낚시 형은 조획성능을 위한 조건을 만족하면서도 기계화 조업도 가능한 절충형의 구조이다.