Earticle

이 연구는 4차 산업혁명이 이슈화 되기 이전 전통적인 실업자훈련(기간·전략, 일반직종)과 신산업 분 야에 맞는 훈련직종을 지속적으로 확대해온 신기술 훈련의 노동시장 성과를 비교하는데 있다. 대표적 인 실업자훈련을 신기술, 기간·전략, 일반직종으로 선정하고, 노동시장 성과를 취업률, 고용유지율, 임 금으로 설정하여, 각 사업별 성과 현황과 효과크기를 산출하여 노동시장 성과를 비교하였다. 주요결과는 첫째, 실업자훈련의 취업률 현황은 신기술(67.7%), 기간·전략(65.6%), 일반직종(51.8%) 순이며, 취업 효과크기는 신기술이 기간·전략에 비해 취업할 확률이 2.3% 더 높고(RR=1.023), 일반직 종에 비해 13.6% 더 높으며(RR=1.136), 기간·전략은 일반직종에 비해 12.3% 더 높았다(RR=1.123). 둘 째, 실업자훈련의 고용유지율 현황은 신기술(70.9%), 기간·전략(62.8%), 일반직종(61.2%) 순이며, 고용 상실 효과크기는 신기술이 기간·전략에 비해 고용을 상실할 확률이 25.9% 더 낮고(RR=0.741), 일반직 종에 비해 30.3% 더 낮으며(RR=0.697), 기간·전략은 일반직종에 비해 0.6% 더 낮았다(RR=0.994). 즉, 신기술은 기간·전략과 일반직종에 비해 취업자가 고용을 상실할 확률이 25～30% 더 낮아 고용을 유지 할 확률이 더 높고, 기간·전략과 일반직종은 미세한 차이는 있지만 고용상실 확률이 거의 1에 가까워, 고용을 유지할 확률은 유사하게 더 낮았다. 셋째, 실업자훈련의 임금 현황(월 기본급)은 신기술(235.7만 원), 기간·전략(203.3만원), 일반직종(175.9만원) 순이며, 임금 효과크기는 신기술이 기간·전략에 비해 작은 효과크기로 더 높고(SMD=0.29), 일반직종에 비해 큰 효과크기로 더 높으며(SMD=0.62), 기간·전 략이 일반직종에 비해 작은 효과크기로 더 높았다(SMD=0.25).

This study compared and analyzed the labor market performance of traditional training for the unemployed(Key Strategic, General Occupations) before the 4th industrial revolution became an issue and New Technology training, which has continuously expanded training occupations suitable for new industries. Representative unemployed training was selected as New Technology, Key Strategic, and General Occupation, and labor market performance was set as employment rate, employment retention rate, and wage, and labor market performance was compared by calculating the current status and effect size of each project. In conclusion, first, the employment rate of unemployed training was in the order of New Technology(67.7%), Key Strategic(65.6%), and General Occupation(51.8%). The employment effect size was 2.3% higher for New Technology than Key Strategic(RR=1.023), 13.6% higher than for General Occupations(RR=1.136), and 12.3% higher for Key Strategic than for General Occupations(RR=1.123). Second, the employment retention rate of unemployed training was in the order of New Technology(70.9%), Key Strategic(62.8%), and General Occupations(61.2%). The effect size of job loss was 25.9% lower for New Technology than Key Strategic(RR=0.741), 30.3% lower than for General Occupation(RR=0.697), and 0.6% lower for Key Strategic than for General Occupation(RR=0.994). Third, monthly basic salary for unemployed training were in the order of New Technology(2.357 million won), Key Strategic(2.033 million won), and General Occupations(1.759 million won). The effect size is higher for New Technology with a small effect size compared to Key Strategic(SMD=0.29), and higher than for General Occupations with a larger effect size(SMD=0.62), and with a smaller effect size for Key Strategic than for General Occupations(SMD=0.25).

The cell permeability and cytotoxic effects of different-sized zinc oxide (ZnO) particles were investigated using a human colorectal adenocarcinoma cell line called Caco-2. Morphological observation by scanning electron microscopy revealed that three zinc oxides with different mean particle sizes (ZnO-1, 20 nm; ZnO-2, 90~200 nm; ZnO-3, $1\sim5\;{\mu}m$) tended to aggregate, particularly in the case of ZnO-1. When cytotoxicities of all three sizes of zinc oxide particles were measured at concentration ranges of $1\sim1000\;{\mu}g$/mL, significant decreases in cell viability were observed at concentrations of $50\;{\mu}g$/mL and higher. Among the three zinc oxides, ZnO-1 showed the lowest viability at $50\;{\mu}g$/mL in Caco-2 cells, followed by ZnO-2 and ZnO-3. The permeate concentration of ZnO-1 from the apical to the basolateral side in the Caco-2 model system after four hours was about three-fold higher than that of either ZnO-2 or ZnO-3. These results demonstrated that ZnO-1, with a 20 nm mean particle size, had poorer viability and better permeability in Caco-2 cells than ZnO-2 and ZnO-3.

Stereolithography (SLA) is a technique using a laser beam to cure a photopolymer liquid resin with three-dimensional computer-aided design (CAD) data, The accuracy of the prototype, the build time, and the cured properties of the resins are controlled by the SLA process parameters such as the size of the laser beam, scan velocity, hatch spacing, and layer thickness, In particular, the size of the laser beam is the most important parameter in SLA, This study investigated the curing properties of photopolymers as a function of the laser beam size, The cure width and depth were measured either on a single cure line or at a single cure layer for various hatch spacings and laser beam sizes, The cure depth ranged from 0.23 to 0.34 mm and was directly proportional to the beam radius, whereas the cure width ranged from 0.42 to 1.07 mm and was inversely proportional to the beam radius, The resulting surface roughness ranged from 1.12 to $2.23{\mu}m$ for a ratio of hatch spacing to beam radius in the range 0.5-2.0 at a beam radius of 0.17 mm and a scan velocity of 125 mm/sec.

Many hyperparameters have to be tuned to have a robust convolutional neural network that will be able to accurately classify images. One of the most important hyperparameters is the batch size, which is the number of images used to train a single forward and backward pass. In this study, the effect of batch size on the performance of convolutional neural networks and the impact of learning rates will be studied for image classification, specifically for medical images. To train the network faster, a VGG16 network with ImageNet weights was used in this experiment. Our results concluded that a higher batch size does not usually achieve high accuracy, and the learning rate and the optimizer used will have a significant impact as well. Lowering the learning rate and decreasing the batch size will allow the network to train better, especially in the case of fine-tuning.

The effect of rebirthing technique on the genetic algorithm (GA)-based size optimization is investigated. The GA mimics the principles of nature and it can gradually improve structural design through biological operations such as fitness, selection, crossover and mutation. However, premature optimum has been often detected in the generic GA with continuous design variable. Since then, the so-called rebirthing technique has been proposed to avoid this problem. However, the performance of the rebirthing technique has not been reported. Therefore, the size optimizations of spatial structures are tackled to investigate the performance of the rebirthing technique on the generic GA. From numerical results, it is well proved that the rebirthing technique is very effective to produce the optimum values regardless of the values of parameters used in the GA operations.

When the ambient air pressure was 0.1 kg/cm , there were few spherically formed droplets, which showed very badly fragmented state. The average particle size of the particles constituting the droplet was about 40 nm. When the air pressure increased to 0.5 kg/cm 2 , the ratio of the spherical droplet forms increased, but still showed a state of severe disruption. The average particle size of the particles was reduced to about 35 nm. As the air pressure increased to 3 kg/cm 2 , the ratio of spherical droplet form significantly increased, the degree of fragmentation even further decreased and the average particle size decreased to 30 nm. When the air pressure increased from 0.1 to 1 kg/cm 2 , the XRD peak intensity showed little change, but the specific surface area was decreased. As the air pressure increased to 3 kg/cm 2 , the intensity of XRD peaks showed a little decrease, while the specific surface area increased.

본 연구는 목표 추구 상황에서 실행의도의 개수가 목표 관련 행동에 미치는 효과를 확인하기 위해 두 개의 연구를 수행하였다. 연구 1에서는 실행의도의 개수가 목표중요성 인식을 거쳐 실행 실패에 대한 예상된 후회감에 미치는 매개효과를, 연구 2에서는 목표 추구 행동에미치는 실행의도의 개수 효과가 조절초점에 의해 조절됨을 검증하고자 하였다. 연구 1의 분석결과, 실행의도가 1개인 조건보다 3개인 조건에서 목표중요성 지각이 높았으며, 목표중요성 인식이 높을수록 실행 실패에 대한 예상된 후회감이 증가하였다. 즉, 실행의도의 개수가 목표중요성 지각의 매개를 통해 실행 실패에 대한 예상된 후회감을 증진시키는 실행의도의 개수 효과가발견되었다. 한편, 연구 2에서는 실행의도의 개수가 목표중요성 지각과 실행 실패에 대한 예상된후회감에 미치는 개수 효과가 촉진초점 조건에서는 나타나지 않고 예방초점 조건에서만 나타나는 조절초점의 조절효과가 발견되었다. 본 연구에서 발견한 실행의도의 개수 효과를 근거로 목표 추구 행동과 관련한 추후 연구 방향과 본 연구의 학문적･실무적 시사점을 논의하였다.

Two studies were performed to investigate the effect of set-size of implementation intention on goal related behaviors in goal pursuit. The purpose of Study 1 was to verify how set-size effect of implementation intention on anticipatory regret for implementation intention failure is mediated by goal importance perception whereas, in Study 2, moderating role of regulatory focus in set-size effect of implementation intention was verified. In Study 1, it was found that, compared to one implementation intention condition, three implementation intentions condition elicited higher perception of goal importance, which in turn increased anticipatory regret for implementation intention failure. That is, set-size effect of implementation intention on anticipatory regret for implementation intention failure was mediated by goal importance perception. Results of Study 2 showed that set-size effect of implementation intention was not found for promotion focused participants but for prevention focused participants which indicates that consumer regulatory focus moderates set-size effect of implementation intention found in Study 1. Future research and academic/practical implications of this study on set-size effect of implementation intention in consumer goal pursuit behavior are discussed.

목적: 본 연구는 라벤더와 라벤더 블렌딩 에센셜 오일이 성인의 심리적 요인에 미치는 효과 크기를 비교 분석하여 라벤더 에센셜 오 일에 대한 이해를 높이고, 효율적인 활용 방안을 제시하기 위해 메타분석을 실시하였다. 방법: 라벤더와 라벤더 블렌딩 에센셜오 일이 심리적 관련 요인에 미친 효과 크기를 분석하기 위해 10년간(2013년 1월-2023년 12월) 출판된 연구물들을 수집하였다. 자료 의 선정은 PICOS 형식에 따라 수량화된 평균값과 표준편차를 제시한 실험군과 대조군의 사전-사후를 비교하는 연구를 선정하였으 며, 메타분석 전문프로그램인 Biostat사(Englewood, USA)의 CMA 4 (comprehensive meta-analysis version 4)를 이용하여 분석하 였다. 결과: 라벤더 단독 에센셜 오일의 경우 불안(0.731)과 스트레스(0.730)에 효과가 높았으며, 그 다음으로 수면의 질(0.673), 피 로(0.601)의 순이었다. 라벤더 블렌딩 에센셜 오일의 경우 수면의 질(1.383)이 효과크기가 가장 높았으며, 그 다음으로 피로(1.159), 스트레스(0.789), 불안(0.638)의 순이었다. 즉, 라벤더 에센셜 오일을 사용한 심리적요인의 개선은 불안감과 스트레스의 완화를 위 해서는 단독으로 사용하고, 수면의 질과 피로의 개선을 위해서는 블렌딩으로 사용하는 것이 효과가 높았다. 결론: 본 연구를 통해 성인의 심리적요인(불안, 수면의 질, 스트레스 및 피로)의 개선을 위해 사용된 라벤더와 라벤더 에센셜오일의 사용 효과가 있는 것 을 알 수 있었다. 이러한 효과크기 분석의 결과는 라벤더와 라벤더 블렌딩 에센셜오일에 대한 객관적인 결과의 근거자료를 제공하 는데 큰 의의가 있으며, 차후 전반적인 심리적요인에 대한 효과를 확인하기 위해 다양한 연구들이 필요하다고 판단된.

Purpose: This study analyzed the effect size of lavender essential oil and lavender blended essential oils on adult psychological factors. A meta-analysis was conducted to recommend an effective application strategy for improving psychological factors in adults. Methods: To analyze the effect size of lavender essential oil and lavender blended essential oils on psychological factors in adults, studies published over the last 10 years (January 2013 to December 2023) were collected. Studies were selected based on the population, intervention, comparison, outcomes, and study-format focusing on those that compared the pre and post psychological health of experimental group and control group and presented the mean and standard deviation. Data were analyzed using the version 4 software by Biostat (Englewood, USA). Results: Treatment with lavender essential oil alone showed highly positive effect on anxiety (0.731) and stress (0.730), followed by positive effects on sleep quality (0.673) and fatigue (0.601). Furthermore, treatment with lavender blended essential oils showed the most positive effects on sleep quality (1.383), followed by fatigue (1.159), stress (0.789), and anxiety (0.638). Conclusion: This study, discovered that lavender essential is effective in relieving anxiety and stress when used to improve adult psychological factors (anxiety, sleep quality, stress, and fatigue), and lavender blended essential oils are particularly effective in improving sleep quality and reducing fatigue. These results are expected to be valuable in prescribing treatments for individuals of various ages and lifestyles suffering from various psychological factors.

기존의 유한 요소 연구에서는 근사하고자하는 함수의 변화가 크거나 불연속에 가까운 경우 이러한 변 화를 해석하기 위하여 필요한 요소의 숫자를 단계적으로 증가시켜 가며 근사의 적정성을 살펴보게 된다. 본 연구에서는 기존방법과는 차별된 무요소 해석에 대한 가능성을 살펴보기 위하여 간단한 포아송 모델 문제를 활용하여 최적 파티션 함수의 크기에 대해 알아보았다. 본 연구는 무요소해법을 이용하여 함수를 근사 할 때 파티션 함수의 최적 크기가 존재함을 시사한다. 파티션 함수의 최적크기는 무요소법을 이용 하여 유로피안이나 아메리칸 옵션의 그릭을 살펴볼 때 유용하다. 무요소 해석을 위한 파티션 함수의 크 기에 대한 최근의 연구 결과들을 살펴보면 파티션 함수가 완전히 겹치지 않고 일부 포개질 경우 더 정확 히 문제를 풀 수 있다고 알려져 있다. 하지만 파티션함수의 크기가 극단적으로 커지는 경우에는 연구결 과를 찾을 수 없었다. 새로운 모델링 기법인 무요소법의 경우 파티션 함수의 크기를 키울수록 방정식의 해의 변화를 더 효율적으로 기술할 수 있으리라 기대하였으나 특별한 경우에는 기존연구 결과와 일부 상반된 결과가 얻어짐을 확인 하였다. 즉, 기존 연구에서는 파티션 함수의 겹치는 영역이 작아져 파티션 함수의 크기가 커지면 커질수록 좋은 결과를 얻었으나 파티션 함수의 겹치는 영역이 극단적으로 작아지 면 오히려 그 반대의 현상이 나타날 수도 있음을 확인하였다.

There is a tight link between the size of flat-top region and the gradient of the partition of unity function. Recent studies show that the condition number of the system can grow arbitrarily large with linear finite element shape functions as a partition of unity even though local approximation functions are linearly independent. As a result, a flat-top partition of unity function is introduced to avoid linear independence. The wide flat-top region in the partition of unity function has been known to ensure the linear independence of mesh-free basis functions. The wider the flat-top is, the smaller so better in the condition number. However, the wider flat-top partition of unity function could result in a large gradient of the partition of unity function as well as large condition number while having a strongly linear independent local basis functions. We demonstrate this phenomenon in a simple Poisson model problem when the flat-top region expands and starts to fill up the support of the partition of unity functions. For the particular problems we have considered, we find that there is an optimal size for the flat-top region in the support of partition of unity function.

Background and Objective: With the advancement of cancer treatments and increased life expectancy, managing breakthrough cancer pain (BTcP) is essential to improve the quality of life for cancer patients. This study aimed to compare the major rapid onset opioids in Korea based on their characteristics and costs to determine the best option for each patient. Methods: Based on sales information from IQVIA-MIDAS, sublingual fentanyl tablet (SLF), fentanyl buccal tablet (FBT), and oral transmucosal fentanyl citrate (OTFC) were selected as the top three drugs for the treatment of BTcP in Korea, considering them the most comparable drugs. The cost and cost-pain relief ratio of the drugs for short-term (1 month) and long-term (1 year) treatment were compared and the ease of administration based on various factors, including pharmacokinetics, onset of action, and administration procedures were evaluated. Results: SLF was evaluated as the best overall in terms of rapid onset of action, ease of administration, and drug cost and also had the highest market share. SLF had the lowest cost pain relief ratio for both the initial and supplemental treatment for the 1- month pain intensity difference 15 (PID15) ratio. However, for the 1-month PID30 ratio, SLF was not superior to OTFC or FBT. The longer the breakthrough cancer pain duration, the more cost-effective the other rapid onset opioids. Conclusion: The rapid onset opioids that fit the patient’s breakthrough cancer pain pattern have the best cost-effectiveness.

An experiment was conducted to observe the effect of polybag size on the growth and quality of Khaya anthotheca seedlings during September 2016 to June 2017 at the nursery of Silvicultural Research Division of Bangladesh Forest Research Institute. Three different polybag size such as T1 (15 cm×23 cm), T2 (13 cm×18 cm) and T3 (11 cm×15 cm) with four replications were used for the experiment. The experiment was designed in Completely Randomized Design (CRD) with four replications. Different sized polybags showed significant influence on survival percentage (T1-100%, T2-93.5%, T3-88%) and growth parameters (height, root collar diameter, leave number and root length) of the seedlings. The species grown in T1 size polybag was observed to be superior to other bag size. Dickson’s Quality index of seedlings raised in T1 size polybag was observed highest value which is the indicator of best quality seedlings. Therefore, the use of T1 poly bag size can be suggested for seedling production of K. anthotheca in the nursery.

도시화와 산업화로 인한 불투수 면적 증가로 비점오염물질이 포함된 초기우수 발생이 증가하고 강우 시 미처리 하수의 유 역하천 유입으로 하천 수질관리에 현실적인 어려움을 겪고 있다. 본 연구에서는 초기우수 및 강우 시 미처리 하수의 인 저감 효율 향상을 위하여 EAFRS를 흡착제로 사용한 인 흡착종정의 최적화를 목적으로 수행되었다. 인 흡착 반응 시 슬래그 입도, 표면개질 여부 그리고 교반강도에 따른 인 제거량 조사를 통해 인 흡착공정의 최적조건을 도출하였다. 실험결과 슬래그 입도 가 작아질수록 인 흡착 효율이 증가하는 것으로 확인되었고 철염을 이용한 슬래그 표면개질 여부는 표면개질 슬래그와 비 개 질 슬래그 사이의 인 제거 효율의 차이는 크지 않았지만 철염을 이용한 개질 약품으로 인한 pH의 영향으로 칼슘과 인의 결 합보다 철이온과 인의 결합이 주도적으로 발생한 것으로 나타났다. 세라믹 볼을 이용한 교반 조건에서 인 흡착 효율은 크게 증가하였고 교반 방식의 여부는 인 흡착 효율 증가에 주요한 요인으로 밝혀졌다. 마지막으로 인 흡착 전후 슬래그의 미세구 조 변화와 화학적 특성을 조사하기 위해 FE-SEM, XRD, FT-IR분석을 수행하였다.

First flush having non-point pollutants have been increasing due to the increase in impermeable area by urbanization and industrialization, and there is a real difficulty in river water quality management due to CSOs and first flush. The purpose of this study is to optimize the phosphorus adsorption process using EAFRS as an adsorbent to improve the phosphorus reduction efficiency of CSOs. During the phosphorus adsorption reaction, the optimum conditions for the phosphorus adsorption process were derived by investigating the amount of phosphorus removal according to the slag particle size, surface modification and mixing intensity. According to the study, the smaller the slag particle size, the higher the phosphorus adsorption efficiency, and difference in phosphorus removal efficiency between the surface-modified slag using iron salts and the non-modified slag was not large as to whether surface was modified, But It was judged that iron ions and phosphorus prefer to bond more than that of phosphorus and calcium in surface modified slag. Under the mixing conditions with ceramic balls, the phosphorus removal rate tended to increase significantly, thus mixing method was judged to be a major factor in increasing the phosphorus adsorption efficiency. Lastly, FE-SEM, XRD and FT-IR analysis were performed to investigate the changes in the microstructure and chemical characteristics of the slag before and after phosphorus adsorption.

Currently, many studies using natural polymers (bio-mass) are in progress to replace microplastics, which are causing serious environmental problems. Among them, cellulose is the most abundant natural polymer on earth and is known as one of the suitable materials to replace plastic materials since it is not-toxic, human-compatible, and biodegradable. However, natural cellulose has a limitation that it is not easily dissolved in general organic solvents due to the presence of crystalline regions and hydrogen bonds between cellulose chains. One of the cellulose derivatives, carboxymethyl cellulose (CMC), has strong anionic and hydrophilic properties and is easily soluble in water. In this study, we tried to produce CMC microbeads with a narrow particle size distribution. CMC was dissolved in water and microbeads were formed using microfluidic channel technology. We will discuss the effect of syringe needle diameter on the particle size distribution of CMC beads, when manufacturing CMC beads using microfluidic channel technology.

Background: We are developing a small size dosimeter for dose estimation in particle therapies. The developed dosimeter is an optical fiber based dosimeter mounting an radiation induced luminescence material, such as an OSL or a scintillator, at a tip. These materials generally suffer from the quenching effect under high LET particle irradiation. Materials and Methods: We fabricated two types of the small size dosimeters. They used an OSL material Eu:BaFBr and a BGO scintillator. Carbon ions were irradiated into the fabricated dosimeters at Heavy Ion Medical Accelerator in Chiba (HIMAC). The small size dosimeters were set behind the water equivalent acrylic phantom. Bragg peak was observed by changing the phantom thickness. An ion chamber was also placed near the small size dosimeters as a reference. Results and Discussion: Eu:BaFBr and BGO dosimeters showed a Bragg peak at the same thickness as the ion chamber. Under high LET particle irradiation, the response of the luminescence- based small size dosimeters deteriorated compared with that of the ion chamber due to the quenching effect. We confirmed the luminescence efficiency of Eu:BaFBr and BGO decrease with the LET. The reduction coefficient of luminescence efficiency was different between the BGO and the Eu:BaFBr. The LET can be determined from the luminescence ratio between Eu:BaFBr and BGO, and the dosimeter response can be corrected. Conclusion: We evaluated the LET dependence of the luminescence efficiency of the BGO and Eu:BaFBr as the quenching effect. We propose and discuss the correction of the quenching effect using the signal intensity ratio of the both materials. Although the correction precision is not sufficient, feasibility of the proposed correction method is proved through basic experiments.

초기균열을 갖는 대부분의 구초체는 부재크기가 증가함에 따라 강도가 저하한다. 이러한 현상을 크기효과(size effect)라고 한다. 유리, 금속, 콘크리트 동, 구조재료중에서 콘크리트는 비록 초기균열이 없더라도 이 size effect 현상을 보인다. 현존의 크기효과 법칙에 따르면 매우 큰 콘크리트 구조체는 거의 하중을 저하할 수 없다. 그러나 실제로는 초기 균열이 없는 경우 상당한 크기의 응력을 저항할 수 있다. 이러한 현상은 매우 큰 구조체와 작은 구조체는 강도기준의 적용이 합당하고, 그 중간 크기의 구조체는 비선형파괴역학의 적용이 합당함을 말한다. 이 논문에서는 비선형파괴역학에 근거하여 유도된 실험식에, 기존의 실험치를 이용하여 비선형회귀분석올 행하여 실험상수를 정함으로써 일축압축, 할열(splitting)인장 및 전단강도에 대한 실험식을 제시한다.

In most of the structural members with initial cracks, the strength tends to decrease as the member size increases. This phenomenon is known as size effect. Among the structural materials of glass, metal or concrete, etc., concrete represents the size effect even without initial crack. According to the previous size effect law, the concrete member of very large size can resist little stress. Actually, however, even the large size member can resist some stress if there is no initial notch. This means that the fracture mechanism of very small or very large size member follows strength criterion, but the medium size member follows non-linear fracture mechanics (NLFM). In this study, the empirical models which are derived based on nonlinear fracture mechanics are proposed according to the regression analysis with the existing test data of large size specimens for uni-axial compression test, splitting tensile test and shear test of reinforced concrete beams.

This study investigates the effects of the size of copper sheets on the plastic deformation behavior in a microscale deep drawing process. Tensile tests are conducted on the copper sheets to study the flow stress of the materials with different grain sizes before carrying out the microscale deep drawing experiments. After the tensile tests, a novel desktop-sized microscale deep drawing system is used to perform the microscale deep drawing process. A series of microscale deep drawing experiments are subsequently performed, and the experimental results indicate that an increase in the grain size results in the reduction of the deformation load of the copper sheets due to the effects of the surface grain. The results also show that the blank holder gap improves both the formability of copper sheets and the material flow.

국내 포장 콘크리트의 품질관리는 KS 규정에 따라 재령 28일 휨 인장강도를 기준으로 평가되고 있으며, 현재 대부분 사용되고 있는 휨 인장강도 시험체는 상대적으로 큰 $150{\times}150{\times}550mm$ 시험체를 사용하고 있다. 이에 따라 시험체의 취급이 어렵고 양생조의 활용도가 떨어지고 있는 실정이다. 이에 따라 본 연구는 휨 인장강도 시험체를 줄여 이 같은 문제점을 해결하고자 하였다. 이를 위해 KS에서 규정되고 있는 시험체 크기의 내에서 로그 스케일에 따른 압축강도 및 휨 강도 시험을 실시하고, 시험체 크기를 변수로 설정하여 강도 및 표준편차를 분석하였다. 또한 이와 같은 실내 실험을 바탕으로 Bazant가 제안한 크기 효과 법칙(Size effect law, SEL)의 예측식을 사용하여 비교 분석함으로써 시험체 크기간의 상관성을 검토하여 콘크리트 포장의 품질 평가시 시험체 크기 축소를 위한 기초자료로 활용하고자 한다.

The quality for the domestic pavement is evaluated based on flexural strength at the age of 28 days in accordance with KS regulation. Most specimens of the flexural tensile strength used currently are relatively large ones with a dimension of $150{\times}150{\times}550mm$. Accordingly, it is difficult to treat the specimens, and the utilization of a curing tank is low. In this paper, the study tried to resolve the problem by specimen size specified in the code. For this purpose, a flexural strength test was conducted according to the log scale within the specimen size specified by the KS. And, based on the results of this experiment, a comparative analysis was conducted using the prediction formula of Size Effect Law (SEL) proposed by Bazant to examine the correlation between specimen sizes, so as to use the result as basic data for the reduction of the specimen size in the quality evaluation of concrete pavement.