• 한국염색가공학회지
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• 제22권3호
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• pp.187-193
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• 2010

The effects of molecular weight (MW) and concentration on the rheological properties of poly(vinyl alcohol) (PVA) solutions in dimethyl sulfoxide (DMSO) were investigated at $30^{\circ}C$. Ubbelohde viscometer and rotational rheometer were employed for dilute and concentrated regime, respectively. In the dilute regime, the Mark-Houwink exponent ($\alpha$) of the solutions determined from three different MWs proved 0.73. The critical concentration (C*), in which the entanglement and overlap of polymer molecules began to take place, decreased with increasing the MW of PVA. Huggins constant ($K_H$) values ranged from 0.33 to 0.45 over the MW examined. In the log-log plot of $\eta_{sp}$ versus [$\eta$]C, the PVA with higher degree of polymerization (DP) gave a greater slope exhibiting the inflection point in the vicinity of C*. In the dynamic viscosity ($\eta'$) curve, the PVA solutions of DP 1700 presented Newtonian fluid behavior over most of the frequency range examined. However, the lower Newtonian flow region reduced with increasing the DP. As the PVA concentration increased, $\eta'$ was increased and the onset shear rate for pseudoplasticity was decreased. In the Cole-Cole plot, PVA solutions showed almost a single master curve in a slope of ca. 1.65 regardless of the DP. However, the increase of the concentration from 8 to 12 wt% for PVA solutions of DP 5000 decreased the slope from 1.73 to 1.57. In the tan $\delta$ curve, the onset frequency for sol-gel transition was shifted from 154 to 92 rad/s with increasing the DP from 3300 to 5000 and from 192 to 46 rad/s with increasing the concentration from 8 to 12 wt%. In addition, longer relaxation time ($\lambda$) was observed with increasing the DP and concentration.

• 한국음향학회지
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• 제10권2호
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• pp.5-12
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• 1991

본 논문에서는 한국어 연결 숫자음 인식을 하였다. 처리 시간을 줄이기 위하여 벡터양자화와 1-段 DP 법을 결합하는 방법을 도입하였으며, 표준패턴의 수를 줄이기 위한 새로운 group-labelling 기법을 제안하였다. 여기서 group-labelling은 벡터양자화에 의해 연결 숫자음을 각각 group으로 분류하여 labelling에 줌으로서 인식 대상이 되는 표준패턴의 수를 줄여주는 방법이다. 이 방법을 평가하기 위하여 3 연결 숫자음을 대상으로 실험한 결과, labelling된 group의 선택 수가 적을수록 표준패턴의 수가 감소하므로써 계산량을 감소시킬 수 있었다.

• International Journal of Precision Engineering and Manufacturing
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• 제3권3호
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• pp.12-20
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• 2002

As numerous sensors and actuators are used in many automated systems, various industrial networks are adopted for real-time distributed control. In order to take advantages of the networking, however, the network implementation should be carefully designed to satisfy real-time requirements considering network induced delays. This paper presents an implementation scheme of a networked control system via Profibus-DP network fur real-time distributed control. More specifically, the effect of the network induced delay on the control performance is evaluated on a Profibus-DP testbed. Also, two conventional PID gain tuning methods are slightly modified fur fouling controllers fur the networked control system. With appropriate choices for gains, it is shown that the networked control system can perform almost as well as the traditional control system.

• 한국의류학회지
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• 제28권9_10호
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• pp.1265-1272
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• 2004

The purpose of this study is to develope wrinkle recovery property, DP rating of Tencel by using BTCA(1,2,3,4-butanetetracarboxylic acid) and MgCl$_2$ that does not make water pollution. The adoptable condition to improve the wrinkle resistance and DP rating was determined 10％ BTCA(o.w.f), 3％ catalyst(o.w.f), 0.5％ softener(o.w.f), 5min padding time, 150$^{\circ}C$ curing temperature, 2min curing time and pH 2.7. It was proven that ester groups were formed and cross-links increased by treating Tencel with BTCA. By XPS diffraction, Tencel treatment using BTCA was proved not to affect crystal formation.

• Journal of Korean Neurosurgical Society
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• 제64권4호
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• pp.495-504
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• 2021

Three-dimensional printing (3DP) applications possess substantial versatility within surgical applications, such as complex reconstructive surgeries and for the use of surgical resection guides. The capability of constructing an implant from a series of radiographic images to provide personalized anatomical fit is what makes 3D printed implants most appealing to surgeons. Our objective is to describe the process of integration of 3DP implants into the operating room for spinal surgery, summarize the outcomes of using 3DP implants in spinal surgery, and discuss the limitations and safety concerns during pre-operative consideration. 3DP allows for customized, light weight, and geometrically complex functional implants in spinal surgery in cases of decompression, tumor, and fusion. However, there are limitations such as the cost of the technology which is prohibitive to many hospitals. The novelty of this approach implies that the quantity of longitudinal studies is limited and our understanding of how the human body responds long term to these implants is still unclear. Although it has given surgeons the ability to improve outcomes, surgical strategies, and patient recovery, there is a need for prospective studies to follow the safety and efficacy of the usage of 3D printed implants in spine surgery.

• 한국자동차공학회논문집
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• 제23권3호
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• pp.279-286
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• 2015

To achieve lightweight design, research & development of various lightweighting technologies such as hydroforming are underway worldwide. In the case of hydroforming, application of ultra high strength steel is essential for weight reduction of the car. However, considering common high-strength carbon steel, it is not suitable to the actual hydroformed parts since the lack of formability. DP steel offers an outstanding combination of strength and formability as a result of their microstructure. DP steel has high strength and good formability but it's difficult to secure stable quality of welding section because of softening of weld section and chemical composition. Therefore, most of companies use LASER welding when making high strength tube. Electric resistance welding is excellent production method for steel tube manufacturing considering the productivity. Optimum electric resistance welding technology is needed to be developed for application of high strength hydroformed parts using DP steel. This study is comprehensive research & development from electric resistance welding to actual formabililty evaluation.

• 대한금속재료학회지
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• 제50권3호
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• pp.224-232
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• 2012

In this study, the effect of hot-stamping heat treatment on the microstructure and hardness of TWB(Tailor Welded Blank) laser joints in Al-Si-coated boron steel and Zn-coated DP(Dual Phase)590 steel was investigated. In the TWB joints without heat treatment, hardness profiles showed local hardness deviation near the fusion zone. However, there was no hardness deviation in the heat treated specimen and its hardness was higher than that of the one without the heat treatment, due to a fully martensite microstructure. In the TWB joints of both the boron and DP steels, the maximum hardnesses were observed at the HAZ(Heat Affected Zone) near the base metal, and the hardness decreased gradually to the base metal. In the heat treated joints, the hardnesses of the HAZ and the base metal of the boron steel side were similar to the maximum hardness of the weld, while those of the HAZ and the base metal of the DP steel side were higher than the maximum hardness.

• Journal of Animal Science and Technology
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• 제62권3호
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• pp.409-419
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• 2020

This study evaluated the effects of breed and gender in Duroc (D), Pietrain (P), and crossbred (DP) pigs. Loin samples were collected from D (n = 79), P (n = 42), and DP (n = 45) pigs. Intramuscular fat content was significantly lower in P (p < 0.001), and pH was lowest in DP pigs (p < 0.001). Gilts had higher intramuscular fat (IMF) and pH values than did castrated males (p < 0.05). Water-holding capacity was lower in DP pigs than that in D and P pigs (p < 0.001). Shear force in DP pigs was higher than that in D and P pigs (p < 0.001). Lightness and yellowness of meat in DP pigs was increased compared with coloring of P pig meat (p < 0.01). Meat from DP pigs was redder compared with meat from in D and P pigs, and it was higher in gilts than in castrates (p < 0.001). The C16:0 content was lower in P and DP pigs than in D pigs (p < 0.01). C18:2 content was higher in P and DP pigs than in D pigs (p < 0.001). Unsaturated and saturated fatty acids increased in P pigs compared with levels in D pigs (p < 0.05). Our results suggest that meat quality can be controlled by crossbreeding to increase or reduce selected properties. This study provides the basic data on the meat characteristics of F1 DP pigs. Thus, further study should be conducted to estimate the meat quality of various crossbreeds.

• 한국정보전자통신기술학회논문지
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• 제16권6호
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• pp.489-498
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• 2023

하드웨어의 성능 및 컴퓨팅 기술의 발전 덕분에 기후환경 변화를 대비하기 위해 기후예측 모델 또한 발전하고 있다. 한국 기상청은 GloSea6를 도입하여 슈퍼컴퓨터를 이용하여 기상 예측을 하고있으며, 각 대학 및 연구 기관에서는 중소규모 서버에서 사용하기 위해 저해상도 결합모델인 Low-GloSea6를 사용하여 기상 연구에 활용하고 있다. 본 논문에서는 중소규모 서버에서의 기상 연구의 원활한 연구를 위해 Low-GloSea6의 Intel VTune Profiler를 사용한 분석을 진행하였으며 1125.987초의 CPU Time을 수행하는 대기모델의 tri_sor_dp_dp 함수를 Hotspot으로 검출하였다. 수치적 연산을 진행하는 기존 함수에 머신러닝 기법의 하나인 비선형 회귀모델을 적용 및 비교하여 머신러닝 적용 가능성을 확인하였다. 기존 tri_sor_dp_dp 함수의 실제 연산되는 값인 1e-3 ~ 1e-20의 범위를 가지는 Output Data인 변수 "Px"를 기준으로 평가하였을때 K-최근접 이웃 회귀 모델은 MAE가 1.3637e-08, SMAPE가 123.2707%로 가장 우수하게 나타났으며 RMSE의 경우 Light Gradient Boosting Machine 회귀 모델이 2.8453e-08로 가장 우수한 성능을 보이는 것으로 측정되었다. 따라서 Low-GloSea6 수행 과정 중 tri_sor_dp_dp 함수의 데이터를 추출 후 비선형 회귀 모델을 적용한 결과로 기존의 tri_sor_dp_dp 함수의 수치적 연산 값과 K-최근접 이웃 회귀 모델을 비교하였을 때 SMAPE가 123.2707%의 오차가 발생하는 것으로 측정되어 기존 모듈의 대체 가능성이 있다는 것을 확인하였다.

• 한국심리학회지:학교
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• 제17권1호
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• pp.17-38
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• 2020

본 연구에서는 국내 학령기 아동을 대상으로 아동·청소년행동평가척도 조절곤란프로파일(Child Behavior Checklist Dysregulation Profile; CBCL-DP)의 요인구조를 조사하고, CBCL-DP특성을 보이는 집단(임상군)과 그렇지 않은 집단(정상군)간 부적응 및 문제행동 수준에 차이가 있는지 확인하고자 하였다. CBCL-DP의 가장 적합한 요인구조를 확인하기 위해 선행연구에서 제시한 3가지 경쟁모형에서 확인적 요인분석을 실시하였으며, 그 결과 단일요인모형(One-factor)과 2차요인모형(Second order)보다 Bifactor모형이 가장 좋은 적합도를 보였다. 가장 적합한 요인구조의 타당성을 확인하기 위해 관련 변인들과의 회귀경로를 계산한 결과 Bifactor모형에서 CBCL-DP는 부모가 보고한 집행기능곤란과 담임교사가 보고한 학교적응 및 강점난점의 모든 하위요인들과 관련되어 있었으며, 불안/우울, 공격행동, 주의집중문제의 3가지 요인들은 차별화된 연관성을 보였다. CBCL-DP의 특성을 나타내는 집단의 부적응 및 문제행동 수준을 CBCL-DP 특성을 보이지 않는 정상군과 비교한 결과, CBCL-DP 특성을 보이는 아동은 정상군 아동보다 집행기능 곤란 정도가 더 높았으며, 학교생활 적응을 잘 하지 못하고 바람직한 행동을 할 가능성이 낮은 것으로 나타났다. 결과적으로 CBCL-DP는 특정 증후군(AAA)보다 여러 가지 다양한 측면에서 부정적 결과와 관련이 있었으며, 선행연구들의 요인구조와 본 연구 표본이 부합하고 있다는 점은 광범위한 조절곤란 증후군으로 CBCL-DP를 개념화하는데 일관되고 통합적인 연구결과를 제시했음을 시사한다. 또한 CBCL-DP는 정서·행동문제가 결합된 고위험군 아동을 조기발견하고 중재함에 있어 학교 및 상담 장면에서 심층적이고 전문적인 진단도구로서 유용하게 사용될 수 있을 것으로 기대된다. 이러한 연구결과를 바탕으로 본 연구의 의의, 한계점 및 향후 연구 방향에 대해 논의하였다.