Metal halide perovskite nanocrystals, due to their high absorption coefficient, high diffusion length, and photoluminescence quantum yield, have received significant attention in the fields of optoelectronic applications such as highly efficient photovoltaic cells and narrow-line-width light emitting diodes. Their energy band structure can be controlled via chemical exchange of the halide anion or monovalent cations in the perovskite nanocrystals. Recently, it has been demonstrated that chemical exfoliation of the halide perovskite crystal structure can be achieved by addition of organic ligands such as noctylamine during the synthetic process. In this study, we systematically investigated the quantum confinement effect of methylammonium lead bromide (CH3NH3PbBr3, MAPbBr3) nanocrystals by precise control of the crystal thickness via chemical exfoliation using n-octylammonium bromide (OABr). We found that the crystalline thickness consistently decreases with increasing amounts of OABr, which has a larger ionic radius than that of CH3NH3 + ions. In particular, a significant quantum confinement effect is observed when the amounts of OABr are higher than 60 %, which exhibited a blue-shifted PL emission (~ 100 nm) as well as an increase of energy bandgap (~ 1.53 eV).

As the demand for the monitoring of VOCs increases, various unpowered colorimetric sensors are being developed, but the performance evaluation method of the developed sensors has not been systematically established. In this study, the device, experimental process, and data calculation methods for the performance evaluation of the colorimetric sensors were proposed. An aluminum chamber (70W× 128 L × 40 mm H) was designed to expose the sensor to a constant concentration of VOCs. In addition, an experimental apparatus was devised to evaluate the effect of environmental factors (temperature and humidity) affecting the ability of the sensor to detect VOCs. To calculate the color change value of the sensor corresponding to the concentration of VOCs, the ‘peak wavelength method’ that analyzes the wavelength of the highest intensity for high-concentration VOCs and the ‘spectral centroid method’ using a weighted arithmetic average for low-concentration VOCs were used. As a result of evaluating the ability of the colorimetric sensor to detect VOCs, which was made of polydimethylsiloxane (PMDS) by the method proposed in this study, the wavelength change values (bandgap shift) of the sensor for 1,000 ppm of benzene, toluene, oxylene, and acetone were 0.898 nm, 2.304 nm, 5.775 nm, and 0.249 nm, respectively. The precision was calculated by repeatedly measuring the sensing ability of the sensor 5 times for each type of VOCs. The precision of the sensor responses to benzene, toluene, o-xylene, and acetone were 15.23%, 7.84%, 4.14%, and 30.00% RSD, respectively. The method proposed in this study can be used to evaluate the performance of various types of VOCs colorimetric sensors.

본 연구는 체육수업 참여 청소년의 그릿, 자기결정성, 자기결정성, 긍정심리자본, 관계성 지지의 관계성을 파악하여 긍정적인 교수자의 자율성 지지와 그에 대한 열정에 대한 영향 여부를 확인하는데 있다. 본 연구에서는 청소년 541명의 판단표본추출법에 의거한 대상자의 결과를 통해서 실시하였다. 연구의 결과는 다음과 같다. 유의미한 결과를 나타낸 것은 그릿은 자율성 지지와 통계적으로 유의미한 정(+)의 영향을 미치는 것으로 나타났다. 관계성 지지는 자율성 지지와 통계적으로 유의미한 정(+)의 영향을 미치는 것으로 나타났다. 자율성 지지는 교사의 열정에 통계적으로 유의미한 정(+)의 영향을 미치는 것으로 나타났다.

In this study, a nanocrystalline FeNiCrMoMnSiC alloy was fabricated, and its austenite stability, microstructure, and mechanical properties were investigated. A sintered FeNiCrMoMnSiC alloy sample with nanosized crystal was obtained by high-energy ball milling and spark plasma sintering. The sintering behavior was investigated by measuring the displacement according to the temperature of the sintered body. Through microstructural analysis, it was confirmed that a compact sintered body with few pores was produced, and cementite was formed. The stability of the austenite phase in the sintered samples was evaluated by X-ray diffraction analysis and electron backscatter diffraction. Results revealed a measured value of 51.6% and that the alloy had seven times more austenite stability than AISI 4340 wrought steel. The hardness of the sintered alloy was 60.4 HRC, which was up to 2.4 times higher than that of wrought steel.

High-strength low-alloy (HSLA) steels show excellent toughness when trace amounts of transition elements are added. In steels, prior austenite grain size (PAGS), which is often determined by the number of added elements, is a critical factor in determining the mechanical properties of the material. In this study, we used two etching methods to measure and compare the PAGS of specimens with bainitic HSLA steels having different Nb contents These two methods were nital etching and picric acid etching. Both methods confirmed that the sample with high Nb content exhibited smaller PAGS than its low Nb counterpart because of Nb’s ability to hinder austenite recrystallization at high temperatures. Although both etching approaches are beneficial to PAGS estimation, the picric acid etching method has the advantage of enabling observation of the interface containing Nb precipitate. By contrast, the nital etching method has the advantage of a very short etching time (5 s) in determining the PAGS, with the picric acid etching method being considerably longer (5 h).

We investigate the effect of phosphorous content on the microstructure and magnetic properties of Fe83.2Si5.33-0.33xB10.67-0.67xPxCu0.8 (x = 1–4 at.%) nanocrystalline soft magnetic alloys. The simultaneous addition of Cu and P to nanocrystalline alloys reportedly decreases the nanocrystalline size significantly, to 10–20 nm. In the P-containing nanocrystalline alloy, P atoms are distributed in an amorphous residual matrix, which suppresses grain growth, increases permeability, and decreases coercivity. In this study, nanocrystalline ribbons with a composition of Fe83.2Si5.33-0.33xB10.67- 0.67xPxCu0.8 (x = 1–4 at.%) are fabricated by rapid quenching melt-spinning and thermal annealing. It is demonstrated that the addition of a small amount of P to the alloy improves the glass-forming ability and increases the resistance to undesirable Fex(B,P) crystallization. Among the alloys investigated in this work, an Fe83.2Si5B10P1Cu0.8 nanocrystalline ribbon annealed at 460oC exhibits excellent soft-magnetic properties including low coercivity, low core loss, and high saturation magnetization. The uniform nanocrystallization of the Fe83.2Si5B10P1Cu0.8 alloy is confirmed by high-resolution transmission electron microscopy analysis.

The Life-sustaining Treatment Decisions Act has became enforced in 2018. Patients' decision-making on life-sustaining treatments can change according to their health status and situations and thus should be understood as the process requiring continuous care. Therefore, it is necessary to build a support system to help patients' decision-making at end-of-life care including life-sustaining treatments. Nurses provide continuous care at the bedside and play a significant role in supporting patients' and their families' decision-making about end-of-life care. Based on reviewing literature and the enforcing process of the Life-sustaining Treatment Decisions Act, this paper described nurses' nursing care activities to support decision-making on life-sustaining treatments. The nursing care activities are 'empathetic support for the decision-making,' 'respect for patients and families as agents for the decision-making,' and 'support for the decision-making as a counselor.' It can emphasize the importance of a nurse's role as a support system for patients’ and their families' decision-making about end-of-life care.

The (Ga1-xZnx)(N1-xOx) solid solution is attracting extensive attention for photocatalytic water splitting and wastewater treatment owing to its narrow and controllable band gap. To optimize the photocatalytic performance of the solid solution, the key points are to decrease its band gap and recombination rate. In this study, (Ga1-xZnx)(N1-xOx) nanofibers with various Zn fractions are prepared by electrospinning followed by calcination and nitridation. The effect of the composition and crystallinity of electrospun oxide nanofibers on the morphology and optical properties of the obtained solid-solution nanofibers are systematically investigated. The results show that the final shape of the (Ga1-xZnx) (N1-xOx) material is greatly affected by the crystallinity of the oxide nanofibers before nitridation. The photocatalytic properties of (Ga1-xZnx)(N1-xOx) with different Ga:Zn atomic ratios are investigated by studying the degradation of rhodamine B under visible light irradiation.

The effect of sintering conditions on the austenite stability and strain-induced martensitic transformation of nanocrystalline FeCrC alloy is investigated. Nanocrystalline FeCrC alloys are successfully fabricated by spark plasma sintering with an extremely short densification time to obtain the theoretical density value and prevent grain growth. The nanocrystallite size in the sintered alloys contributes to increased austenite stability. The phase fraction of the FeCrC sintered alloy before and after deformation according to the sintering holding time is measured using X-ray diffraction and electron backscatter diffraction analysis. During compressive deformation, the volume fraction of strain-induced martensite resulting from austenite decomposition is increased. The transformation kinetics of the strain-induced martensite is evaluated using an empirical equation considering the austenite stability factor. The hardness of the S0W and S10W samples increase to 62.4-67.5 and 58.9-63.4 HRC before and after deformation. The hardness results confirmed that the mechanical properties are improved owing to the effects of grain refinement and strain-induced martensitic transformation in the nanocrystalline FeCrC alloy.

연구는 고등학생이 온라인 수업에서 느끼는 교수실재감이 자기결정성동기의 기본심리욕구를 매개하여 자기조절학습능력에 미치는 영향을 검증하고, 이 변인 간 관계에서 남녀 학생 간 성별에 따른 차이가 있는 지 검증하고자 하였다. 이를 위해 J지역에 위치한 3개 고등학교에 설문지를 배포하였고 최종적으로 383명의 학생의 자료를 구조방정식모형 분석방법을 사용하여 분석하였다. 그 결과 첫째, 온라인 수업상황에서 학생들이 인식하는 교수실재감은 자기결정성동기와 자기조절학습능력에 영향을 미치는 것으로 나타났다. 둘째, 자기결정성 동기의 기본심리욕구 세 가지 하위요인 중 유능성만 온라인 수업에서의 교수실재감과 자기조절학습능력 변인 간에 매개역할을 하는 것으로 나타났다. 셋째, 온라인 수업에서의 학생들이 인지하는 교수실재감과 자기결정성 동기의 기본심리욕구, 자기조절학습능력 간의 구조적 관계에서 남녀 학생 간 성별차이는 나타나지 않았다. 본 연구의 결과는 교사가 온라인 수업 중 학생의 자기조절학습능력을 발달시키기 위해 교수실재감을 높이는 것이 필요하며, 그 과정에서 자기결정성동기의 기본심리욕구 중, 교수실재감과 자기조절학습능력을 매개하고 있는 유능감 뿐 아니라, 매개하지 못한 자율성과 관계성의 기본심리욕구도 강화할 필요가 있음을 시사하고 있다.

경제성장이 고도화되면 일반적으로 산업구조는 제조업에서 서비스산업으로 변화한다. 한국의 각 산업별 노동시장을 살펴보면 이런 현상이 명확히 나타나고 있다. 특히 무역의존도가 높은 한국산업에서 물류산업의 중요성이 부각되고 있다. 물류산업의 노동시장에서 대졸여부에 따른 임금격차가 존재하고 심화되고 있다는 것이 통계자료로 확인되었다. 이것은 동산업의 노동시장이 학력에 따라 분절되었다는 것을 의미한다. 인적자본론을 적용하여 고졸이하를 인적자본이 없는 저학력 노동으로, 대졸이상을 인적자본이 체화된 고학력노동으로 구분하여 독립 생산요소로 설정하였다. 이런 전제하에 3요소(자본, 저학력 노동자, 고학력 노동자) 콥-다글라스 생산함수를 상정하고, 외생변수로 산출량, 세계화와 중립적 기술진보를 포함한 학력별 노동수요 추정식을 유도하여 결정요인분석을 시행하였다. 추정결과 물류산업에서는 생산요소의 상대가격(, , )과 같은 노동시장의 내적요인이 저학력노동수요와 고학력노동수요에 영향을 미치지 못하였다. 반면 산출량, 세계화와 기술진보와 같은 물류산업의 외생적 변화가 물류산업의 학력별 노동시장에 유의미하게 영향을 미치는 것으로 나타났다. 즉 산출량변화에 대해 저학력노동수요가 고학력노동수요보다 더 탄력적으로 영향을 미친다. 세계화 진전은 고학력노동수요의 증가로 나타났고 기술진보는 저학력노동수요의 감소와 고학력노동수요의 증가에 영향을 친 것으로 나타났다. 이와 같은 추정결과를 바탕으로 다음과 같은 정책적 대안을 마련할 수 있다. 첫째 경기변동에 따라 저학력노동수요 변화가 더 심하기 때문에 저학력 노동의 고용안정 정책이 필요하다. 둘째, 기술진보는 생산성을 향상시켜 총생산량을 높이지만 물류산업 노동시장에서는 저학력 노동수요의 감소로 실업이 발생할 수 있기 때문에 이것에 대비한 노동정책이 필요하다. 셋째, 세계화의 진전은 고학력노동수요의 증가를 유발하므로 물류산업에 필요한 인재양성정책이 필요하다.

Most of the open-source decision tree algorithms are based on three splitting criteria (Entropy, Gini Index, and Gain Ratio). Therefore, the advantages and disadvantages of these three popular algorithms need to be studied more thoroughly. Comparisons of the three algorithms were mainly performed with respect to the predictive performance. In this work, we conducted a comparative experiment on the splitting criteria of three decision trees, focusing on their interpretability. Depth, homogeneity, coverage, lift, and stability were used as indicators for measuring interpretability. To measure the stability of decision trees, we present a measure of the stability of the root node and the stability of the dominating rules based on a measure of the similarity of trees. Based on 10 data collected from UCI and Kaggle, we compare the interpretability of DT (Decision Tree) algorithms based on three splitting criteria. The results show that the GR (Gain Ratio) branch-based DT algorithm performs well in terms of lift and homogeneity, while the GINI (Gini Index) and ENT (Entropy) branch-based DT algorithms performs well in terms of coverage. With respect to stability, considering both the similarity of the dominating rule or the similarity of the root node, the DT algorithm according to the ENT splitting criterion shows the best results.

In defense acquisition system, testing and evaluation is a very important procedure that can ensure the completeness of capability while deciding whether to mass-produce or purchase weapons systems. But it always includes realistic restrictions that involve a variety of stakeholders, but lack of time, resources, and budget. Therefore, in the process of planning a test and evaluation, proper number of prototypes and reliability of test results, along with test items and evaluation criteria, are frequently discussed as sensitive agendas. In reality, however, rather than statistical judgments, the number of prototypes and tests are determined by business logic such as duration and budget. Otherwise, most theoretical studies do not adequately reflect the business logic of test assessment. In this study, we propose a number of prototype and tests method that can statistically reasonably verify the performance of the inorganic system considering the characteristics of each test and evaluation project. To this end, we consider the theory related to determining the number of prototypes and tests, and present examples by separating whether to secure the magnitude of effects that have a significant impact on statistical judgment. This study could contribute to the development of empirical methodologies that can adequately coordinate reality and theory in the field of defense test evaluation while ensuring statistical reliability of test evaluation results.

PURPOSES : The aim of this study is to develop a decision-making model for safety countermeasures based on the characteristics of water deer roadkills. METHODS : Through field investigation, 113 water deer roadkills with factors related to environment, geometry, and ecology were collected from May 2018 to April 2019. From the collected database, the characteristics of water deer roadkills were analyzed. An analytic hierarchy process was applied to establish a decision-making model to prevent water deer roadkills from appearing. RESULTS : The likelihood of water deer roadkills increases in summer and winter, road sections in suburban areas with low traffic volume, surrounding farmlands, and areas without illumination. The results show that factors such as safety, ecology, road geometry, policy consistency, and the willingness of the local government are critical factors for establishing the decision-making model. CONCLUSIONS : Appropriate safety countermeasures for water deer roadkills can be developed if the roadkill frequency, degree of sight distance restriction, speed limit for controlling overspeeding, roadkill severity, degree of forest area, traffic volume, and willingness of competent authorities are considered as essential variables.

In SMEs, technological innovation is recognized as an important tool in terms of sustainable growth. This study analyzed the determinants of technological innovation by using the information of the corporate panel DB composed of local SMEs. The internal factors were added with technological innovation capacity and production capacity and the industrial cluster environment was first applied to external factors. Also, whether the industrial cluster environment influences technological innovation through R&D capabilities, the mediating effect was tested with the Sobel Test. Among the internal and external factors, the most important determinant was marketing ability, and a policy was proposed to develop measures to increase R&D capability with mediating effect. Among the technological innovation variables, which are dependent variables, the most determinant factor was the proportion of new product sales. For this, it is considered that additional research such as longitudinal research with the concept of repetition and parallax using the corporate panel DB is necessary.

현재 성인지 감수성이라는 아직은 법적으로 추상적인 개념이 성폭력범 죄재판에 사용됨으로써 이의 근거지움이 논란을 불러일으키고 있다. 따라서 본 논문에서는 성인지 감수성이 헌법상 성적 자기결정권의 함의에 따른 역할을 성폭력범죄재판에서 제대로 구현하여 피해자의 성적 자기결정권을 보호 내지 보장하는 수단 또는 판단기준으로 작동 가능한지를 살펴보았다. 성폭력범죄재판에서 성인지 감수성이 보다 객관적·효과적으로 피해자의 성적 자기결정권을 보호하기 위해서는 그 판단기준이 되는 피해자 평균적 관점에 대한 보편적 경험칙으로서의 근거를 마련할 필요가 있다. 성인지 감수성은 성폭력범죄재판 담당법관의 삶의 궤적과도 밀접한 관련성을 가지므로 개인마다 그 편차가 발생할 수밖에 없다는 점은 성인지 감수성이 지니는 가장 큰 맹점일 것이다. 따라서 성폭력범죄재판에서 경험칙으로서 작동하기 위해서는 성인지 감수성의 개념 정립에 따른 명확한 지침이 요구된다. 성인지 감수성이라는 아직은 익숙하지 않은 개념을 성폭력범죄재판의 판단기준으로 이용하기에는 아직까지 이론적 근거가 축적되어 있지 않다는 지적도 있다. 본 논문의 의의는 헌법상 성적 자기결정권의 함의를 살펴보고 이러한 헌법상 함의가 형법 등 법률에 잘 구현되어 있는지를 살펴보는데 있다. 앞으로 그동안 축적되어온 대법원법리를 충실히 반영하여 형사법원칙에 상응하는 성인지 감수성에 대한 개념정의와 판단기준 척도개발에 연구의 방향을 맞춤으로써 성인지 감수성 개념의 추상성에 기댄 가벌성의 확장 문제를 해소할 필요가 있다. 이에 대한 연구가 계속 축적된다면 성인지 감수성도 헌법상 성적 자기결정권을 실질적으로 구현하는 기준으로 충분히 자리매김 될 수 있을 것이다.