• 한국생산제조학회지
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• 제25권4호
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• pp.281-289
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• 2016

Agitation is a secondary process used to increase the PR stripping force on an ITO-glass surface; it is an efficient approach to stripping during production. It activates the stripper to chemically penetrate the PR layer and assists by breaking down the physical bonding forces at the surface. In this study, different stripping tests were conducted by varying the dipping time, the composition, the strip temperature, and the stripper concentration. Optimal PR strip conditions were estimated by using comparative visual inspection of stripped sample surfaces. The stripping process was affected by changes in the moving speeds and the sample positions. It was confirmed that the stripping capability improved at a dilute stripper ratio of 20-40% and a strip temperature of $30-40^{\circ}C$ and within 60 s of strip time.

• Journal of Electrical Engineering and Technology
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• 제13권5호
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• pp.1965-1977
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• 2018

This paper proposed a regenerative braking system (RBS) strategy for battery electric vehicles (BEVs) with a hybrid energy storage system (HESS) driven by a brushless DC (BLDC) motor. In the regenerative braking mode of BEV, the BLDC motor works as a generator. Consequently, the DC-link voltage is boosted and regenerative braking energy is transferred to a battery and/or ultracapacitor (UC) using a suitable switching pattern of the three-phase inverter. The energy stored in the HESS through reverse current flow can be exploited to improve acceleration and maintain the batteries from frequent deep discharging during high power mode. In addition, the artificial neural network (ANN)-based RBS control mechanism was utilized to optimize the switching scheme of the vehicular breaking force distribution. Furthermore, constant torque braking can be regulated using a PI controller. Different simulation and experiments were implemented and carried out to verify the performance of the proposed RBS strategy. The UC/battery RBS also contributed to improved vehicle acceleration and extended range BEVs.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2003년도 추계 학술발표회논문집
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• pp.98-106
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• 2003

To construct pile-supported wharf structures that must support heavy horizontal loads, both vertical piles and batter piles are used. Batter piles are used to secure the bearing capacity against the horizontal loads. However, past case histories have shown that the heads of batter piles are vulnerable because these heads are subjected to excessive axial loads during earthquakes. Therefore, the aseismatic reinforcement method must be developed to prevent batter pile heads from breaking due to excessive seismic loads. Two different connecting methods of either inserting rubber or ball-bearing between batter pile head and upper plate were proposed to improve the aseismatic efficiency. Three large-scale pile head models(rubber type model, ball-bearing type model, and fixed type model) were manufactured and horizontal loading tests were peformed for these models. The results showed that the force-displacement relationship of the fixed type model was linear, but that of the rubber type model and the ball-bearing type model was bilinear. The increase in the horizontal displacement led to the increase in the horizontal stiffness of the rubber type models and the decrease in that of the ball-bearing type model. Compared with the values for fixed type model, the damping ratios of the rubber type model and the ball-bearing type model increased about 33~185％ and 263~269％, respectively.

• 한국축산식품학회지
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• 제39권3호
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• pp.503-509
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• 2019

The aim of this study was to compare the effects of number of washes and salt addition on the meat quality in protein recovered from Alaska Pollock compared with pork leg. Various properties of protein recovered from Alaska Pollock (C, washed twice, no salt) and pork leg (T1, washed twice, no salt; T2, two washes, salt added; T3, washed four times, no salt; and T4, washed four times, salt added) were assessed in this study. Pork leg samples exhibited better color (more whiteness, less yellowness) than Alaska Pollock samples. In pork leg samples, four washes (T3, T4) during processing yielded whiter, less yellow protein than two washes (T1, T2). Overall, the textural property measures were higher in pork leg samples (T2, T3, and T4) than in other samples. Breaking force, jelly strength, and folding resistance were significantly higher in salt-treated pork leg samples (T2, T4) than in the other samples. Our findings demonstrate that protein recovered from pork leg has better color parameters, and physical strength compared with Alaska Pollock-derived protein. A higher number of wash steps and treatment with salt during processing were furthermore found to yield better color, and physical strength in the protein samples.

• Design & Manufacturing
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• 제15권3호
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• pp.13-18
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• 2021

In plate forming technology, cylindrical drawing process is widely used in industry due to technological development. In this study, we used stainless steel 3042B and stainless steel 304J1, which are the most commonly used materials in the production of cold and hot water tanks for water purifiers, among cylindrical drawing products. Under the same conditions, the thickness of the sidewall of the product formed by drawn experiment was studied. As a result of the experiment, the bottom thickness of stainless steel 304J1 was considered to be thick. It is judged that the defect rate can be reduced by changing the breaking phenomenon of the floor surface of the cold and hot water bottles to the material of stainless steel 304j1. Stainless steel 304 2B material shows a sharp change in thickness from punch corner R to sidewall position, while stainless steel 304J1 material showed a uniform change from punch corner R to sidewall position. Stainless steel 304J1 material is considered to improve the clamping of the product in the process of extracting the product after hand drawing. The appearance of stainless steel 3042B products is considered to produce more wrinkles in the flange, which exerts greater tensile force on the sidewall during molding, resulting in uneven sidewall thickness.

• Ocean Systems Engineering
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• 제11권4호
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• pp.313-330
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• 2021

In this study, the dynamic interaction between an Arctic Spar and drifting level ice is examined in time domain using the newly developed ice-hull-mooring coupled dynamics program. The in-house program, CHARM3D, which is the hull-riser-mooring coupled dynamic simulator is extended by coupling with the open-source discrete element method (DEM) simulator, LIGGGHTS. In the LIGGGHTS module, the parallel-bonding method is implemented to model the level ice using an assembly of multiple bonded spherical particles. As a case study, a spread-moored Artic Spar platform, whose hull surface near waterline is the inverted conical shape, is chosen. To determine the breaking-related DEM parameter (the critical bonding strength), the four-point numerical bending test is used. A series of numerical simulations is systematically performed under the various ice conditions including ice drift velocity, flexural strength, and thickness. Then, the effects of these parameters on the ice force, platform motions, and mooring tensions are discussed. The simulations reveal various features of dynamic interactions between the drifting ice and moored platform for various ice conditions including the novel synchronous resonance at low ice speed. The newly developed simulator is promising and can repeatedly be used for the future design and analysis including ice-floater-mooring coupled dynamics.

• 운동영양학회지
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• 제25권2호
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• pp.33-37
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• 2021

[Purpose] Sex hormones deficiency leads to dramatically bone loss in particular postmenopausal women. Royal jelly has anti-osteoporosis effect due to maintain bone volume in that condition. We hypothesized that royal jelly protein (RJP, a latent residue after extracting royal jelly) also prevents bone deficient in ovariectomized (OVX) female rats, the animal model of postmenopausal women. [Methods] Female Sprague-Dawley rats (n = 30, 6 weeks age old) were sham operated (Sham; sham operated group, n = 7), OVX control group (OC, n = 7), OVX with low RJP intake group (ORL, n = 8), and OVX with high RJP intake group (ORH, n = 8) during 8 weeks experimental periods. In the end point of this experiment, the bone samples (lumbar spine, tibia, and femur) were surgically removed under anesthesia. These bone samples were evaluated bone mineral density (BMD) and bone strength. [Results] BMD of lumbar spine in RJP intake groups (ORL, ORH) were higher than that in OC group (p < 0.05 and p < 0.01) in RJP intake volume dependent manner. BMD of tibial proximal metaphysis and diaphysis in RJP intake groups were also higher than these in OC group (p < 0.01 and p < 0.01 / p < 0.05 and p < 0.001). In addition, breaking force of femur in RJP intake groups were significantly increase compared with that in OC group (p < 0.001 respectively). [Conclusion] These findings indicate that RJP contribute to prevent sex hormone related bone abnormality.

• 한국수산과학회지
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• 제11권1호
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• pp.39-48
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• 1978

본 연구에서는 3-course 구조와 2-course 구조의 랏쉘그물감을 선정하여 그 강도 특성을 조사하고, 이를 구성 섬유의 재료가 같은 매듭그물감 및 관통 그물감의 강도와 비교했다. 실험으로 부터 얻어진 결과를 요약하면 다음과 같다. 1. 랏쉘그물실의 강도가 랏쉘마디에서 감소하느 원인은 장력에 의한 마디의 변형 및 마디에서의 yarn 간의 마찰력에 주로 기인한다고 간주되며, 강도 감소율은 종인에서 $13\%$, 횡인에서 $22\~26\%$ 정도이다. 2. 랏쉘마디는 3-course 구조의 것이 2-course 구조의 것보다 모든 방향의 인장에서 약간 강하고, 마디 형태의 변형도 적다. 3. 주름을 준 상태에서의 랏쉘마디의 강도 $T_R$는 인접하는 다리가 이루는 각을 $\varphi$라 하면 $T_R=T_{R0}-k\varphi$ 로 주어진다. 단, $R_{R0}$는 $\varphi$가 $0^{\circ}$때의 $T_R$의 값, k는 상수이다. 4. 랏쉘그물감의 항장력 ${\sigma}R$ 및 파단에 소요되는 일량 $E_R$는 인장하는 쪽의 그물코 수를 N라 하면 ${\sigma}R=KN$ 또는 ${\sigma}R=K_RN$ 및 $E_R=AN$으로 표시되고, 파단신도는 N에 관계없이 거의 일정하다. 단, K 및 A는 상수이다. 5. 몇개의 다리가 미리 절단되어 있는 경우의 랏쉘그물감의 파단은 미리 절단되어 있는 다리에 인접한 다리의 마디로부터 일어나며, 그때의 항장력, 파단에 소요되는 일량 몇 파단신도의 감소는 비록 하나의 다리가 미리 절단되어 있는 경우라 할지라도 상당히 크다. 6. 랏쉘그물감의 파열강도는 두개의 다리를 인장한 경우의 랏쉘마디의 강도와 거의 같다. 7. 현용의 주된 세 종류의 그물감에 대해 그들을 구성하는 다리의 denier 수를 기준으로 하면, 관통마디가 가장 강하고, 매듭의 강도는 관통마디의 강도의 $69\~76\%$ 정도이다. 랏쉘마디는 종인시는 관통마디 강도의 $71\~74\%$ 로서 매듭과 거의 같은 강도를 가지지만, 횡인시는 매듭의 강도보다 약하여 $62\~67\%$를 나타낸다.

• 대한기계학회논문집A
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• 제39권1호
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• pp.55-62
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• 2015

성형작약탄에 의해 발생되는 금속제트에 대전류 펄스가 인가되면 금속제트 내 외부에 전자기장이형성 되고 생성된 전자기장에 의해 전자기력이 작용하여 금속제트를 분산 및 산란시키게 된다. 대전류펄스 인가장치는 RLC 회로로 구성되어 있고 두 전극판 사이로 금속제트가 관통되어 진행할 때 대전류펄스가 흐르게 된다. 본 연구에서는 ALE 기법을 이용한 2 차원 축 대칭 해석을 통해 두 전극판을 통과할 때의 금속제트 단면 형상을 예측하고, 2 차원 해석 모델에서 얻어낸 금속제트 단면을 3 차원 유한요소 모델로 재구성하여 금속제트에 전류를 직접 인가하였다. 또한, 유한요소해석을 통하여 금속제트에 직접적으로 대전류 펄스를 인가시켜 금속제트의 변형된 형상과 발생하는 전자기력을 계산하였으며, 금속제트의 산란을 일으키는데 영향을 주는 대전류 펄스의 주요 설계변수 특성에 대하여 검증하였다.

• 한국식품과학회지
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• 제28권1호
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• pp.58-65
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• 1996

탄산나트륨, 탄산칼륨과 이들의 혼합염(탄산나트륨/탄산칼륨=0.7-2.0)이 밀가루의 아밀로그래프에 의한 호화성질과 파리노그래프에 의한 반죽성질을 조사하였다. 알칼리제 혼합염(0.16%)이 국수의 성질에 미치는 영향도 아울러 검토하였다. 소금(0.17%)과 알칼리는 아밀로그래프의 호화개시 온도를 감소시켰고 최고점도를 증가시켰으며 그 효과는 탄산나트륨이 가장 현저하였다. 최고점도는 알칼리의 농도가 증가할수록 증가하였고 동일한 농도에서는 혼합비율에 따른 차이는 없었다. 파리노그래프의 흡수율은 소금에 의하여 감소되었고 알칼리제에는 영향을 받지 않았으나 소금과 알칼리제가 동시에 존재할 때는 소금의 효과가 감소하였다. 소금과 알칼리제는 반죽의 안정도를 크게 증가시켰으며 소금의 효과가 더욱 뚜렸하였다. 그러나 소금의 존재시 알칼리제 단독 또는 혼합 사용하였을 때는 농도에 관계없이 알밀로그람과 파리노그람 특성값은 큰 차이를 보이지 않았다. 알칼리제 혼합염의 첨가에 따라 건면의 황색도와 파쇄력이 증가하였고 파쇄력은 혼합비율 1.0에서 가장 큰 값을 보였다. 삶은 국수의 경우 무게와 부피증가 정도는 알칼리제 혼합염의 첨가에 따라 큰 변화가 없었으나 전단력과 압착력은 혼합비율 1.0에서 가장 높은 값을 보였다.