• 대한조선학회논문집
• /
• 제51권6호
• /
• pp.495-502
• /
• 2014

Glass-reinforced polyurethane foam (R-PUF) is widely used as the primary and secondary insulation of Mark-III type liquefied natural gas (LNG) cargo system. And, polyurethane foam (PUF) and polyisocyanurate foam (PIR) are often used for insulation of onshore structures or LNG storage and pipeline system. These polymeric foam materials are known for the characteristics that mechanical properties are dependent on strain rate and temperature. In this study, compression tests for R-PUF, PIR, and PUF were carried out for the estimation of mechanical behaviors under the cryogenic environment. The range of thermal condition was from room temperature to 110K and strain rates were $10^{-3}s^{-1}$ and $10^{-4}s^{-1}$. The test results were analyzed based on the conditions of strain-rate and temperature.

• 한국기술혁신학회:학술대회논문집
• /
• 한국기술혁신학회 2006년도 추계학술대회
• /
• pp.355-368
• /
• 2006

본 연구는 1982년부터 2002년까지 우리나라 15개 산업부분의 패널자료를 이용하여 지식생산함수추정을 시도하였다. 해당 산업부문의 지식생산활동에서 서로 다른 산업부문간에 산호작용영향이 중요하다는 관점을 고려하여 Mark et al. (2005)이 제시한 DSUR(Dynamic Seemingly Unrelated Regression)추정량을 이용하여 관련된 지식생산함수의 모수를 추정하였다. 본 연구의 추정결과를 살펴보면, 우리나라 지식생산함수에서 연구원 규모가 지식생산에 기여하는 탄력성정도는 0.25이며, 기존 지식축적량이 기여하는 탄력성정도는 0.353으로 나타났다. 이러한 실증분석 결과는 우리나라의 경우에 기존 지식축적량이 새로운 지식생산에 기여하는 탄력성정도가 1보다 작음을 보여준다. 지식생산함수의 관하여 추정된 계수의 크기가 시사하는 바는 우리나라의 장기적 경제성장률은 제품 및 서비스생산함수에 관련된 탄력성과 인구성장증가율에 따라서 결정되기 때문에 정부의 직접적인 R&D정책개입보다는 지식관리 및 보급 그리고 공유체계정비라는 간접적 R&D정잭개입을 통하여 지속적인 경제성장전략을 추진해야한다는 주장을 뒷받침한다고 볼 수 있다.

• Computers and Concrete
• /
• 제10권4호
• /
• pp.419-434
• /
• 2012

This paper presents a finite element (FE) model for predicting the nonlinear response and behavior of a reinforced concrete T-beam deficient in shear under cyclic loading. Cracking loads, failure loads, response hysteresis envelopes and crack patterns were used as bench mark for comparison between experimental and FE results. A parametric study was carried out to predict the optimum combination of the open and close crack shear transfer coefficients (${\beta}_t$ and ${\beta}_c$) of the constitutive material model for concrete. It is concluded that when both shear transfer coefficients are equal to 0.2 the FE results gave the best correlation with the experimental results. The results were also verified on a rectangular shear deficient beam (R-beam) tested under cyclic loading and it is concluded that the variation of section geometry has no effect on the optimum choice of the values of shear transfer coefficients of 0.2. In addition, a parametric study based on the variation of concrete compressive strength, was carried out on the T-beam and it is observed that the variation of concrete compressive strength has little effect on the deflection. Further conclusions and observations were also drawn.

• 대한치과보철학회지
• /
• 제49권3호
• /
• pp.214-221
• /
• 2011

연구 목적: 기존 대부분의 유한요소 연구에서는 100%의 골-임플란트 접촉을 가정하여 왔으나 인간사체연구(human retrieval study)에서는 골-임플란트 부착비율이 20-80%라고 보고되었다. 본 연구에서는 비선형 삼차원 유한요소법을 이용하여 실제적인 골-임플란트 접촉을 재현하기 위해 무작위 골접촉 양상을 비교연구하고자 하였다. 연구 재료 및 방법: 컴퓨터단층촬영에서 얻은 영상을 근거로 하여 제작한 골모형에 두 가지 디자인의 임플란트(MK III Br${\aa}$nemark$^{(R)}$, Inplant$^{(R)})$를 상악제2소구치에 해당하는 위치에 식립한 모형을 만들었다. 골질은 골형 2로서 Lekholm과 Zarb의 분류를 따랐다. 각 임플란트 디자인마다 두 가지(40%, 70%)의골-임플란트 접촉비율을 가정하였다. 각디자인과 골접촉율마다 5개의 모형을 제작하여 총 40 개의 모형을 만들었다. 이골-임플란트 접촉을 무작위 섞기방식(random shuffle method)으로 하였고 피질골과 해면골을 다 포함하여 골유착을 시킨 군(wholly randomized osseointegration; W)과 피질골과 해면골을 분리하여 골접촉시키기 위해서 각 0.75 mm마다 무작위 골접촉을 시킨 군(segmentally randomized osseointegration; S)을 비교연구하였다. 결과: 골-임플란트 접촉율이나 임플란트 디자인에 상관없이 W군과 S군 간 maximum von Mises strain의 평균에 있어서 유의성 있는 차이가 없었다(P=.939). 골-임플란트 접촉율이40%보다70%가 von Mises strain이 유의하게 낮았다(P=.007). 골-임플란트 접촉율이 40%일때는 Inplant$^{(R)}$과 MK III Br${\aa}$nemark$^{(R)}$의 변형율 간에는 유의성 있는 차이가 없었으나(P=.116), 골-임플란트 접촉율이 70%일때 Inplant$^{(R)}$에서는 $4886{\pm}1034\;{\mu}m/m$, MK III Br${\aa}$nemark$^{(R)}$에서는 $7134{\pm}1232\;{\mu}m/m$로서 Inplant$^{(R)}$의 von Mises strain이MK III Br${\aa}$nemark$^{(R)}$의 것보다 유의하게 낮았다(P<.0001). 결론: 골-임플란트 접촉을 가정함에 있어서 무작위 섞기방식(random shuffle method)을 이용하여 임플란트 전체에 대해서나 피질골과 해면골을 분리하여 무작위 골-임플란트 접촉을 시키든 간에 통계적으로 유의한 차이가 없어서 표본의 크기에 상관없이 둘 다 유효한 방법이라 할 수 있었다.

• 한국초지조사료학회지
• /
• 제22권2호
• /
• pp.93-100
• /
• 2002

국내에 도입된 오차드그래스 27 품종과 국내 합성 품종인 Hapsung 2호의 종자로부터의 캘러스 형성율, 형성된 캘러스의 크기, 캘러스로부터의 재분화율 및 재분화 효율을 4주령 및 6주령의 캘러스에 대하여 얻은 결과는 아래와 같았다. 1. 4주령의 캘러스에 대한 종자로부터 캘러스의 형성율은 치상 종자의 50% 이상이 캘러스를 형성한 형성율 상위 품종들은 93M > Sparta > Pizza> Condor > Lidaglo > Glorus >Hapsung2 > Frode의 순이었다. 2. 4주령 캘러스의 크기를 직경(cm)으로 표시하였을 때, 최저 0.43cm, 최고 -4.2cm로서 약 10 배의 직경크기의 차이가 있었으나, 대부분은 2.5cm와 4cm의 범위 내에 있었다. 3. 4주령 캘러스로부터의 재분화는 0~36%의 꽤 넓은 범위의 차이를 보였고, 재분화율은 Plano > 아끼미도리> Justus > Lidacta > Currie > Hall mark의 순으로 높았다. 4. 종자로부터의 재분화율을 계산한 재분화 효율의 범위는 0~l7.4%였으며 그 중 Justus가 17.4%로서 비교품종들 가장 높았다. 5. 캘러스 형성율과 캘러스 크기 사이에는 r=0.5765의 상관 관계가 있었고, 캘러스 형성율과 재분화 효율 사이에는 r=0.6365, 캘러스 크기와 재분화 효율 사이에는 r=0.6246였으며, 이 값들은 모두 1%의 높은 유의성이 있었다. 6. 6주령의 캘러스에 대한 종자로부터의 캘러스 형성율은 Condor > Sparta > 93M > Justus > Potomac > Lidaglo > Frode의 순이었다. 7. 6주령 캘러스의 크기는 1.2~5.7cm로서 품종간에 가장 큰 것과 가장 작은 것 사이에 약 5배의 크기 차이를 보였고, 대조품종인 Hap-sung 2호는 직경이 3.8cm로서 비교품종들 사이에서 다소 큰 편이었다. 8. 6주령의 캘러스의 재분화율은 0%에서 100%까지 큰 편차를 보였는데, Plano가 100%의 재분화율을 보여 치상한 종자가 모두가 캘러스 형성이 된 반면 Juno는 전혀 캘러스화 되지 않았다. 9. 종자로부터 캘러스를 거쳐 재분화되는 재분화 효율의 범위는 0~28%로서 4주령의 범위보다 더 커졌으며 전체적으로 4주령의 재분화 효율보다 6주령의 재분화 효율이 더 높아졌다. 특히 Potomac의 경우 4주령에 비하여 6주령의 것이 3배 이상 재분화 효율이 높아졌다. 10. 6주령의 캘러스 형성율과 캘러스 크기사이에는 r=0.8369의 상관관계가 있었고, 캘러스 형성율과 재분화 효율 사이에는 r=0.6683, 캘러스 크기와 재분화 효율 사이에는 r=0.5937였으며, 이 값들은 모두 1%의 높은 유의성이 있었다.

• Journal of Welding and Joining
• /
• 제32권6호
• /
• pp.1-7
• /
• 2014

For the resistance spot welds of CR1180 and GA1180 TRIP steels, the weld quality evaluation method using the digitalized X-ray transmission imaging apparatus was investigated in comparison with the crosssectional examination method. In the case of the resistance spot welding of CR1180, three circular regions, such as WZ(white zone), GZ(grey zone) and DZ(dark zone), appeared on X-ray image and they corresponded to the diameters of indentation mark, nugget and corona bond, respectively. The variation of X-ray transmission thickness due to the thickness variation of the weld seemed to be mainly responsible for the formation of those contrasts. The X-ray image contrast formed from the variation of transmission thickness at the outer border line of DZ could also enable the inspections of the notch shape, nonuniformity of the welding pressure and spatter from its sharpness, concentricity and the normal straight line, respectively. The X-ray image of the resistance spot weld of galvannealed GA1180 TRIP steel was very similar to that of CR1180 TRIP steel except the crown shaped outer border line of DZ which was considered to be due to the melting behavior of zinc having the boiling temperature even lower than the melting temperature of steel.

• 기본간호학회지
• /
• 제8권2호
• /
• pp.160-171
• /
• 2001

Purpose: The purpose of study was to identify the relationship between body image and self-esteem in patients with chronic renal failure. Method The subjects of study were 97 patients with chronic renal failure who were outpatients at K medical center. B hospital, H hospital in Busan. Data were collected from Nov 15th to Dec. 17th, 1999. The instruments used for study were the Body Cathexis Scale and Rogenberg's Self-esteem Scale. Collected data were analyzed by frequency, percentage, mean, standard deviation, t-test, ANOVA, Scheffe test, and Pearson's correlation coefficients. Result: 1 The mean score for body image was $137.46{\pm}22.21$, the mean mark $2.92{\pm}0.47$, and the mean score of self-esteem was $30.80{\pm}8.76$, the mean mark $3.08{\pm}0.87$. 2. There was a significant difference in the score for body image according to educational level (F=5.189, P=.002) and type of residence (F=6.095. P=.001). 3. There was a significant difference in the score for self-esteem according to age (F=3.615, P=.009), educational level (F= 4.772, P=.004), marital status (F=3.498 P=.019) and presence of children (F=2.511, P=.014). 4. Body image in patients with chronic renal failure patients showed significant correlation with self-esteem (r=.519, P=.000). Conclusion: From this study, a relationship between body image and self-esteem in patients with chronic renal failure was identified. Therefore, nursing interventions are needed to promote body image and self esteem in patients with chronic renal patients.

• Archives of Plastic Surgery
• /
• 제41권5호
• /
• pp.535-541
• /
• 2014

Background Patients having unilateral breast reconstruction often require a second stage procedure on the contralateral breast to improve symmetry. In order to provide immediate symmetry and minimize the frequency and extent of secondary procedures, we began performing simultaneous contralateral balancing operations at the time of initial reconstruction. This study examines the indications, safety, and efficacy of this approach. Methods One-hundred and two consecutive breast reconstructions with simultaneous contralateral balancing procedures were identified. Data included patient age, body mass index (BMI), type of reconstruction and balancing procedure, specimen weight, transfusion requirement, complications and additional surgery under anesthesia. Unpaired t-tests were used to compare BMI, specimen weight and need for non-autologous transfusion. Results Average patient age was 48 years. The majority had autologous tissue-only reconstructions (94%) and the rest prosthesis-based reconstructions (6%). Balancing procedures included reduction mammoplasty (50%), mastopexy (49%), and augmentation mammoplasty (1%). Average BMI was 27 and average reduction specimen was 340 grams. Non-autologous blood transfusion rate was 9%. There was no relationship between BMI or reduction specimen weight and need for transfusion. We performed secondary surgery in 24% of the autologous group and 100% of the prosthesis group. Revision rate for symmetry was 13% in the autologous group and 17% in the prosthesis group. Conclusions Performing balancing at the time of breast reconstruction is safe and most effective in autologous reconstructions, where 87% did not require a second operation for symmetry.

• Animal cells and systems
• /
• 제2권1호
• /
• pp.145-152
• /
• 1998

The spinning apparatus and production of secretory silk from silk gland of the black widow spider, Latrodectus mactans were studied with scanning and transmission electron microscopes. The silk glands were located in seven groups on the spinnerets including each pair of major and minor ampullate, 3 pairs of tubuliform, 1 pair of flagelliform, 2 pairs of aggregate, about 50 pairs of pyriform and over 250 pairs of aciniform glands, respect- ively. Each group of silk gland feeds silk into one of the three spinneret pairs. Secretory silk is synthesized from rough endoplasmic reticulum (rER) of glandular epithelial cells. The secretory silk is transported from toe rER into the secretory vacuoles which are grown up by fusion with the surrounding small vesicles including the secretory silk. The secretory vacuoles, which show a gradual increase in electron density with the process of maturity, are formed without involvement of the Golgi complex, suggesting that they do not play an important role in the processing of the secretory silk. The secretory silk products are released by the mechanism of apocrine secretion, losing part of their cytoplasm. Moreover, another type of silk precursor, possibly protein, appears as granular material, and is also discharged to the luminal cavity.

• BMB Reports
• /
• 제39권2호
• /
• pp.167-170
• /
• 2006

Bovine adenosine deaminase undergoes a nondenaturational conformational change at $29^{\circ}C$ upon heating which is characterized by a large increase in heat capacity. We have determined the transition state thermodynamics of the conformational change using a novel application of differential scanning calorimetry (DSC) which employs very slow scan rates. DSC scans at the conventional, and arbitrary, scan rate of $1^{\circ}C/min$ show no evidence of the transition. Scan rates from 0.030 to $0.20^{\circ}C/min$ reveal the transition indicating it is under kinetic control. The transition temperature $T_t$ and the transition temperature interval ${\Delta}T$ increase with scan rate. A first order rate constant $k_1$ is calculated at each $T_t$ from $k_1\;=\;r_{scan}/{\Delta}T$, where $r_{scan}$ is the scan rate, and an Arrhenius plot is constructed. Standard transition state analysis reveals an activation free energy ${\Delta}G^{\neq}$ of 88.1 kJ/mole and suggests that the conformational change has an unfolding quality that appears to be on the direct path to the physiological-temperature conformer.