New piezoelectric and triboelectric materials for energy harvesting are being widely researched to reduce their processing cost and complexity and to improve their energy conversion efficiency. In this study, BaTiO3 films of various thickness were deposited on Ni foams by R.F. magnetron sputtering to study the piezoelectric and triboelectric properties of the porous spongy structure materials. Then piezoelectric nanogenerators (PENGs) were prepared with spongy structured BaTiO3 and PDMS composite. The output performance exhibited a positive dependence on the thickness of the BaTiO3 film, pushing load, and poling. The PENG output voltage and current were 4.4 V and 0.453 μA at an applied stress of 120 N when poled with a 300 kV/cm electric field. The electrical properties of the fabricated PENG were stable even after 5,000 cycles of durability testing. The triboelectric nanogenerators (TENGs) were fabricated using spongy structured BaTiO3 and various polymer films as dielectrics and operated in a vertical contact separation mode. The maximum peak to peak voltage and current of the composite film-based triboelectric nanogenerator were 63.2 V and 6 μA, respectively. This study offers new insights into the design and fabrication of high output nanogenerators using spongy structured materials.

Purpose: This study developed an educational program for structured discussion-based learning, problem-based learning (PBL), and simulation for nursing students. Its effects on learning attitude, problem-solving process, and clinical competence were then analyzed. Methods: This study used a one-group pretest–posttest experimental method among 135 fourth-year nursing students taking the simulation course at a university in D city. We operated the PBL by applying the structured discussion method and simulation education based on four modules covering major diseases among adults. The data collected before and after the program were analyzed using descriptive statistics and paired t-tests. Results: The program significantly improved nursing students’ learning attitude, problem-solving process, and clinical competence. Conclusions: We verified the effects of the simulation education program for structured discussion-based learning and PBL. Further studies are needed to develop and apply simulation educational programs utilizing various devices that can improve learners’ participation and professors’ operational protocols by systematically combining them with different teaching/learning methods.

MoO3 metal oxide nanostructure was formed by hydrothermal synthesis, and a perovskite solar cell with an MoO3 hole transfer layer was fabricated and evaluated. The characteristics of the MoO3 thin film were analyzed according to the change of hydrothermal synthesis temperature in the range of 100 ℃ to 200 ℃ and mass ratio of AMT : nitric acid of 1 : 3 ~ 15 wt%. The influence on the photoelectric conversion efficiency of the solar cell was evaluated. Nanorod-shaped MoO3 thin films were formed in the temperature range of 150 ℃ to 200 ℃, and the chemical bonding and crystal structure of the thin films were analyzed. As the amount of nitric acid added increased, the thickness of the thin film decreased. As the thickness of the hole transfer layer decreased, the photoelectric conversion efficiency of the perovskite solar cell improved. The maximum photoelectric conversion efficiency of the perovskite solar cell having an MoO3 thin film was 4.69 % when the conditions of hydrothermal synthesis were 150 ℃ and mass ratio of AMT : nitric acid of 1 : 12 wt%.

Purpose: Debriefing is very important in simulation-based education. The purpose of this study was to identify the effects of structured team debriefing on clinical performance, self-confidence in nursing activities, and the satisfaction of nursing students, using mind mapping. Method: A non-equivalent control group post-test design was conducted. The participants in the study were 83 nursing students. The experimental group consisted of 42 seniors in 2018, and the control group consisted of 41 seniors in 2019. Data were collected through a self-administered questionnaire and an observed performance checklist. The collected data were analyzed using chi-square and independent t-tests with the statistical software package IBM SPSS/WIN 25.0. Results: There were significant differences in clinical performance (t=7.64, p<.001), self-confidence in nursing activities (t=4.93, p<.001), and learner’ satisfaction (t=2.94, p=.004) between the experimental and the control groups. Conclusion: These results indicate that simulation-based nursing education applying structured team debriefing using mind mapping was effective in improving nursing students' clinical performance, self-confidence in nursing activities, and satisfaction. Thus, there is a need to develop and apply a range of clinical scenarios and debriefing strategies in simulation-based nursing education. Technical and non-technical skills of nursing students also need to be evaluated in simulation-based nursing education using various debriefing methods.

In this study, pitch crosslinked by oxygen function groups was made into activated carbon (AC) and pore structure was observed. The oxygen functional groups were introduced by the addition of waste PET for pitch synthesis. Activation agent ratios used to obtain the AC during the activation process were 1:1, 1:2 and 1:4 (pitch:KOH, w/w). The oxygen content in the prepared pitch was characterized by elemental analysis. Also, the molecular weight of pitch was investigated by MALDITOF. Specific surface area and micropore volume of the prepared AC were determined by the argon adsorption–desorption analysis and calculated using the Brunauer–Emmett–Teller and Horvath–Kawazoe equations, respectively. Micropore fraction of PET-free AC was smaller than that of PET-added AC. At high activation agent ratio, mesopores were created when the micropore structure collapsed. However, in the PET-added AC, due to the oxygen crosslinking effect, the micropore structure and micropore size were maintained even at a high activation agent ratio. Therefore, PET AC was found to have a higher micropore fraction than that of PET-free AC.

본 연구는 발달장애 아동들의 사회적 기술 향상을 위하여 구조화된 감각통합 그룹프로그램을 적용 하였을 때의 효과 입증을 위한 목적으로 진행하였다. 이를 위해 복지관 이용 아동 중 연구 포함기준에 해당하는 3명의 아동을 대상으로 구조화된 감각통합 그룹프로그램을 진행하였고, 프로그램 전과 후에 각각 그룹프로그램의 효과를 확인하기 위해 한국 유아 사회성 기술 검사, 캐나다 작업수행 평가, 감각 프로 파일, 아동용 일상생활활동평가를 시행하였다. 연구결과 3명의 아동 모두 작업수행도, 만족도, 사회성 기술과 일상생활활동의 대부분 영역에서 프로그램 이후 향상된 것으로 나타났다. 감 각처리능력의 변화에서는 프로그램 전과 후에 뚜렷한 차이를 보이지는 않았다. 본 연구결과를 기초로 구조화된 감각통합 그룹프로그램은 사회성 기술, 작업수행에서의 수행도와 만족도 및 일상생활영 역의 긍정적 효과를 보이는 것으로 확인되었다.

Urchin-structured zinc oxide(ZnO) nanorod(NR) gas sensors were successfully demonstrated on a polyimide(PI) substrate, using single wall carbon nanotubes(SWCNTs) as the electrode. The ZnO NRs were grown with ZnO shells arranged at regular intervals to form a network structure with maximized surface area. The high surface area and numerous junctions of the NR network structure was the key to excellent gas sensing performance. Moreover, the SWCNTs formed a junction barrier with the ZnO which further improved sensor characteristics. The fabricated urchin-structured ZnO NR gas sensors exhibited superior performance upon NO2 exposure with a stable response of 110, fast rise and decay times of 38 and 24 sec, respectively. Comparative analyses revealed that the high performance of the sensors was due to a combination of high surface area, numerous active junction points, and the use of the SWCNTs electrode. Furthermore, the urchin-structured ZnO NR gas sensors showed sustainable mechanical stability. Although degradation of the devices progressed during repeated flexibility tests, the sensors were still operational even after 10000 cycles of a bending test with a radius of curvature of 5 mm.

본 논문은 최고경영자(Chief Executive Officer, CEO)의 특성이 기업의 위험관리 의사결정에 어떤 영 향을 미치는지를 분석하고자 하였다. 최고경영자의 특성을 나타내는 변수로 나이와 취득전공을 선정하여 2008년 금융위기 전후로 파생상품을 이용한 제조기업들을 대상으로 구조화파생상품을 이용한 기업들만의 차별화된 특성을 분석하였다. 연구결과는 다음과 같다. 일반적으로 CEO의 나이가 많아질수록 보수적 이고 안정적인 의사결정을 한다는 첫 번째 가설을 검증한 결과, CEO의 나이는 복잡한 구조화파생상품을 이용하는데 별다른 영향을 미치지 못하는 것으로 나타났다. 상경관련 전공자가 파생상품을 더 잘 이해하고 복잡한 구조화파생상품이 위험관리용으로 적절하지 않기에 더 적게 사용할 것이라는 두 번째 가설을 검증한 결과, 비상경계 CEO의 파생상품 이용정도가 상경계 CEO보다 더 높은 것으로 나타나서 가설을 지지하는 것으로 나타났다.

Electrical wire explosion in liquid media is a promising method for producing metallic nanopowders. It is possible to obtain high-purity metallic nanoparticles and uniform-sized nanopowder with excellent dispersion stability using this electrical wire explosion method. In this study, Ni-Fe alloy nanopowders with core-shell structures are fabricated via the electrical explosion of Ni-Fe alloy wires 0.1 mm in diameter and 20 mm in length in de-ionized water. The size and shape of the powders are investigated by field-emission scanning electron microscopy, transmission electron microscopy, and laser particle size analysis. Phase analysis and grain size determination are conducted by X-ray diffraction. The result indicate that a core-shell structured Ni-Fe nanopowder is synthesized with an average particle size of approximately 28 nm, and nanosized Ni core particles are encapsulated by an Fe nanolayer.

Polysilsesquioxanes are essentially hybrid materials consisting of inorganic framework and organic functional groups. A proof of concept study for a new type of gas separation membrane was considered based on the ladder-structured poly(phenyl-co-glycidoxypropyl) silsesquioxanes with phenyl:glycidoxypropyl copolymer ratio of 6:4 (LPG64), which were synthesized by a base-catalyzed sol-gel reaction. Also, by selectively introducing polyethylene oxide (PEO) groups covalently bound to the LPSQ, we effectively suppressed the PEO crystallization, allowing for excellent CO2/H2 and CO2/N2 separation under single as well as mixed gas conditions. Engineering molecular structures of LPSQs will be discussed in detail to investigate the fundamentals of gas transport in LPSQ-based membranes as well as their extended application.

본 연구는 사다리형 폴리실세스퀴옥산 구조에 CO2 친화적인 polyethylene oxide (PEO) 기를 도입하여 우수한 CO2 선택성을 지닌 분리막을 성공적으로 개발하였다. 보다 구체적으로, 세 가지 copolymer 비율 (즉, 40/60, 60/40, 80/20 mol/mol)로 poly(methoxy(polyethyleneoxy) propyl-co-methacryloxypropyl) silsesquioxane을 합성하였고, UV 광경화를 통하여 기계적으로 안정한 분리막을 제조하였다. 이중의 단단한 실록산 백본에 PEO를 공유결합 시킴으로써, PEO의 결정화를 효과적으로 억제하였고, 단일가스와 혼합가스 조건 모두 매우 우수한 CO2/H2 그리고 CO2/N2 분리성능을 지님을 증명하였다.

A simulation method to estimate microstructure dependent material properties and their influence on performance for a honeycomb structured SiC heating element has been established. Electrical and thermal conductivities of a porous SiC sample were calculated by solving a current continuity equation. Then, the results were used as input parameters for a finite element analysis package to predict temperature distribution when the heating element was subjected to a DC bias. Based on the simulation results, a direction of material development for better heating efficiency was found. In addition, a modified metal electrode scheme to decelerate corrosion kinetics was proposed, by which the durability of the water heating system was greatly improved.

Impedancemetric NOx (NO and NO2) gas sensors were designed with a stacked-layer structure and fabricated using LaCrxCo1-xO3 (x = 0, 0.2, 0.5, 0.8 and 1) as the receptor material and Li1.3Al0.3Ti1.7(PO4)3 plates as the solid-electrolyte transducer material. The LaCrxCo1-xO3 layers were prepared with a polymeric precursor method that used ethylene glycol as the solvent, acetyl acetone as the chelating agent, and polyvinylpyrrolidone as the polymer additive. The effects of the Co concentration on the structural, morphological, and NOx sensing properties of the LaCrxCo1-xO3 powders were investigated with powder Xray diffraction, field emission scanning electron microscopy, and its response to 20~250 ppm of NOx at 400 oC (for 1 kHz and 0.5 V), respectively. When the as-prepared precursors were calcined at 700 oC, only a single phase was detected, which corresponded to a perovskite-type structure. The XRD results showed that as the Co concentration of the LaCrxCo1-xO3 powders increased, the crystal structure was transformed from an orthorhombic phase to a rhombohedral phase. Moreover, the LaCrxCo1-xO3 powders with 0 ≤ x < 0.8 had a rhombohedral symmetry. The size of the particles in the LaCrxCo1-xO3 powders increased from 0.1 to 0.5 μm as the Co concentration increased. The sensing performance of the stack-structured LaCrxCo1-xO3/Li1.3Al0.3Ti1.7(PO4)3 sensors was found to divide the impedance component between the resistance and capacitance. The response of these sensors to NO gas was more sensitive than that to NO2 gas. Compared to other impedancemetric sensors, the LaCr0.8Co0.2O3/Li1.3Al0.3Ti1.7(PO4)3 sensor exhibited good reversibility and reliable sensingresponse properties for NOx gases.

3차원 구조광 스캐너를 이용하여 비파괴적, 비접촉적 으로 식물 잎 면적을 측정하는 방법을 고안하고자 하였 다. 3차원 구조광 스캐너를 이용하여 측정한 콩의 잎 면 적은 엽면적 측정기로 측정한 잎 면적과 높은 상관관계 를 보였다. 또한 콩의 V1~V4까지의 각 생장단계마다 3차원 스캔 이미지를 이용하여 측정한 잎 면적은 지상 부를 수확한 후 측정한 생중량 분석 결과와 매우 높은 상관관계(R2=0.98)를 나타내었다. 가뭄 및 염분 스트레 스 환경에서 3차원 스캐너를 이용하여 시간에 따른 콩 의 생장의 변화를 비교한 결과, 대조구의 식물체 잎 면 적은 시간이 경과될수록 증가한 반면 가뭄 및 염분처리 구의 식물체 잎 면적은 처리 12일과 14일 후 각각 감소 하여 처리구 간 뚜렷한 차이를 나타내었다. 이러한 결과 를 통해 3차원 스캐너를 이용하여 다양한 환경에서 식 물체의 잎 면적과 생체량을 효과적으로 추정할 수 있음 을 확인하였다. 사 사 본 연구는 미래창조과학부 중견연구자 지원사업(과제 번호: 20110028162)과 KRIBB 기관고유사업의 연구비 지원으로 수행되었습니다.

We developed an age-based spawner-recruit model incorporating environmental variables to forecast stock biomass and recruits of pelagic fish in this study. We applied the model to the Tsushima stock of jack mackerel, which is shared by Korea and Japan. The stock biomass of jack mackerel (Trachurus japonicus) around Korean waters ranged from 141 thousand metric tons (mt) and 728 thousand mt and recruits ranged from 27 thousand mt to 283 thousand mt. We hind-casted the stock biomass to evaluate the model performance and robustness for the period of 1987~2009. It was found that the model has been useful to forecast stock biomass and recruits for the period of the lifespan of fish species. The model is also capable of forecasting the long-term period, assuming a certain climatic regime.

본 연구는 중소기업에서 실시하고 있는 S-OJT 프로그램 구성요인이 직무성과에 미 치는 영향을 검증하고 S-OJT프로그램의 효용성을 증진할 수 있는 구성요인과 실행방 안을 연구할 목적으로 진행되었으며, 연구결과 S-OJT프로그램 구성요인은 교육훈련 성과에 영향을 미치며, 조직의 지원은 학습자의 특성과 무관하게 영향을 미치는 것으 로 나타났다. 또한 학습동기가 낮은 경우, 교육훈련의 적절성과 환경에, 학습동기가 높 은 경우에는 교육훈련의 훈련전문가의 역량이 성과에 중요한 영향을 미치는 것으로 나타났으며. 학습자 스스로가 학습능력이 높다고 판단하는 경우는 교육훈련 내용의 적절성이 교육훈련 프로그램 성과에 영향을 미치는 것으로 나타났다. 따라서 S-OJT 실시에 있어 조직의 지원은 프로그램 성과에 긍정적인 기여효과가 있으며, 훈련전문가 의 역량은 현업적용도, 직무성과를 높일 것이다. 아울러 훈련프로그램의 성과를 제고하기 위해서는 학습자의 학습동기와 자기효능감 을 높일 방안을 강구해야 한다고 볼 수 있다.