Silicon carbide (SiC) has emerged as a promising material for next-generation power semiconductor materials, due to its high thermal conductivity and high critical electric field (~3 MV/cm) with a wide bandgap of 3.3 eV. This permits SiC devices to operate at lower on-resistance and higher breakdown voltage. However, to improve device performance, advanced research is still needed to reduce point defects in the SiC epitaxial layer. This work investigated the electrical characteristics and defect properties using DLTS analysis. Four deep level defects generated by the implantation process and during epitaxial layer growth were detected. Trap parameters such as energy level, capture-cross section, trap density were obtained from an Arrhenius plot. To investigate the impact of defects on the device, a 2D TCAD simulation was conducted using the same device structure, and the extracted defect parameters were added to confirm electrical characteristics. The degradation of device performance such as an increase in on-resistance by adding trap parameters was confirmed.

본 연구는 아로마 목걸이를 병용한 비대면 수면 프로그램이 불면증 대학생의 수면의 질, 주간졸 림증, 우울 및 스트레스에 미치는 효과를 확인하고자 비동등 대조군 전후 실험설계로 시도되었다. 대상자 는 경기도 S시 소재 E대학에 재학중인 대학생 가운데 불면증상을 호소하는 대상자에게 중재 전후에 자가 설문으로 구성된 수면의 질, 주간졸림증, 우울, 스트레스를 측정하였다. 아로마목걸이를 병용한 비대면 수 면 프로그램은 실험군(n=21)에게 주 1회, 총 6주 동안 적용하였으며 대조군(n=21)에게 수면책자를 제공하 였다. 자료분석은 SPSS 24.0 프로그램을 이용하여 기술통계, Chi-square test, Fisher’s exact test, Independent t-test를 이용하여 분석하였다. 연구결과, 수면의 질(t=-5.87, p<.001), 주간졸음(t=-4.28, p<.001), 우울(t=-4.40, p<.001)에서는 그룹 간 유의한 차이가 나타났으며 스트레스는 유의하지 않았다. 따라서 아로마목걸이를 병용한 비대면 수면 프로그램이 대학생의 수면의 질, 주간졸림증, 우울 증상을 감 소시키는데 유용한 간호중재법으로 활용 가능할 것을 기대된다.

In order to present a predictive drift model, Jeju National University's training ship was tested for about 11 hours and 40 minutes, and 81 samples that selected one of the entire samples at ten-minute intervals were subjected to regression analysis after verifying outliers and influence points. In the outlier and influence point analysis, although there is a part where the wind direction exceeds 1 in the DFBETAS (difference in Betas) value, the CV (cumulative variable) value is 6%, close to 1. Therefore, it was judged that there would be no problem in conducting multiple regression analyses on samples. The standard regression coefficient showed how much current and wind affect the dependent variable. It showed that current speed and direction were the most important variables for drift speed and direction, with values of 47.1% and 58.1%, respectively. The analysis showed that the statistical values indicated the fit of the model at the significance level of 0.05 for multiple regression analysis. The multiple correlation coefficients indicating the degree of influence on the dependent variable were 83.2% and 89.0%, respectively. The determination of coefficients were 69.3% and 79.3%, and the adjusted determination of coefficients were 67.6% and 78.3%, respectively. In this study, a more quantitative prediction model will be presented because it is performed after identifying outliers and influence points of sample data before multiple regression analysis. Therefore, many studies will be active in the future by combining them.

This study aimed to investigate the relationship between the nutrition quotient and the dietary intake of adolescents. A total of 393 adolescents were surveyed to evaluate their Nutrition Quotient for Korean Adolescents (NQ-A) scores and dietary intake. The average age of the survey subjects was 15 years and the average NQ-A score of the subjects was 49.11±13.35. There was no significant difference in the NQ-A scores according to gender and age. The average dietary diversity score was 3.77±0.85, and it was significantly higher in boys than in girls (p< .05) with the scores of 12-14-year-old students being significantly higher than those aged 15-18 years (p< .01). The results of comparing the percentage of recommended intake or adequate intake and the mean adequacy ratio (MAR) according to the NQ-A grade, showed that the ‘High’ grade had a significantly higher intake percentage of vitamin B1, B12, folate, phosphorus, iron and a significantly higher MAR (p< .05). From a long-term perspective, efforts to improve dietary habits are deemed necessary to meet an individual’s nutritional requirements. Adolescents themselves should develop proper eating behaviors and acquire suitable dietary management skills to enhance their nutritional status, ultimately contributing to an improvement in their quality of life.

토석 채취 후 식생복구지의 토양 특성은 복구 식생의 생육에 중요하다. 본 연구는 토석 채취 후 식생복구지와 인접 소나무 및 굴참나무 임분을 대상으로 0∼10cm, 10∼20cm, 20∼30cm 깊이에 토양의 물리·화학적 특성을 조사하였다. 토양용적밀도와 토양 pH는 식생복구지가 소나무나 굴참나무 임분에 비해 유의적으로 높았으나(P<0.05), 유기탄소와 전질소농도는 인접 산림지에 비해 낮았다. 유효 인은 0~10cm 깊이에서 식생복구지 와 산림지 간 유의적인 차이가 없었으나, 교환성 칼슘은 식생복구지가 인접 산림지에 비해 유의적으로 높게 나타났다. 토양 유기 탄소저장량은 식생복구지가 9,896 kg C ha-1로 소나무 임분 131,368 kg C ha-1나 굴참나무 임분 154,381 kg C ha-1에 비해 유의적으로 낮았으며 질소저장량도(식 생복구지: 2,406 kg N ha-1; 소나무: 10,496 kg N ha-1; 굴참나무: 8,081 kg N ha-1) 유사한 경향을 보였다. 그러나 인, 포타슘, 마그네슘 저장량은 식생복구지와 인접 산림 간 유의적인 차이는 없었다. 한편, 칼슘저장량은 식생복구지가 8,998 kg Ca ha-1로 소나무 임분 697 kg Ca ha-1나 굴참나무 임분 660 kg Ca ha-1에 비해 유의적으로 크게 나타났다. 본 연구 결과에 따르면 토석 채취 후 식생복구지는 토양용적밀도와 토양 pH를 낮추고 유기물의 증가와 질소 시비 같은 양분관리가 필요한 것으로 나타났다.

The towing distance, which is speed over the ground, and the water flow quantity, which is speed through the water, were used when estimating the amount of Metapenaeus joyneri resources that rose to the surface at night using the swept area method in order to compare and analyze the difference. It was conducted using a shrimp dredge, trial fishing gear for catching Metapenaeus joyneri. Catch during the entire survey period was 188.9 kg. Monthly catch ranged from 3.1 to 109.2 kg, highest in June and lowest in September. The swept volume calculated using the speed over the ground was about 13% higher than using the speed through the water. Metapenaeus joyneri resources estimated using the towing distance ranged from 320.1 to 14,649.8 kg. Resources estimated using the water flow quantity ranged from 278.5 to 12,886.3 kg. Therefore, the amount of Metapenaeus joyneri resources estimated using the speed over the ground was about 14% higher than the method using the speed through the water, indicating that the amount of resources was overestimated.

A checklist of dietary behavior items for the elderly was developed based on Korean dietary guidelines. First, a literature review was conducted, and 63 preliminary items, including 30 items on food intake, 12 on eating habits, and 21 on dietary culture, were obtained to evaluate the dietary guidelines. The preliminary items were evaluated by experts using Lawshe’s method to verify the content validity. They were then revised, resulting in 52 items: 25, 11, and 16 in the food intake, eating habits, and dietary culture domains, respectively. A face-to-face survey was conducted on 331 people over 65 years of age in the metropolitan area, and their one-day food intake was surveyed using a 24-hour recall method in August 2022. The 48 items, including 24, 11, and 13 items on food intake, eating habits, and dietary culture, respectively, correlated significantly with the evaluation indicators of nutrient intake, such as mean adequacy ratio, dietary diversity score, and nutrient intake density. These items were considered suitable for evaluating the elderly's compliance with dietary guidelines.

This study investigated the effect of Lactiplantibacillus plantarum JSA22-fermented rice drinks on dextran sodium sulfate (DSS)-induced colitis in mice. Twenty-four mice were randomly assigned; No colitis (Con), colitis with tap water (DSS-only), colitis with unfermented rice (DSS-UFR), and colitis with fermented rice (DSS-FR). After inducing colitis with 2% DSS for 5 days, they were given Tap water, UFR drink, or FR drink for an additional 6 days. The DSS-FR group had significantly lower Disease Activity Index (DAI) scores compared to the DSS-only group, but no significant difference with the DSS-UFR group. Colon length was reduced in the DSS-only group. The DSS-only group had significantly higher IL-6 mRNA levels compared to the Con group, while the DSS-FR groups showed significantly lower IL-6 mRNA levels compared to the DSS-only group. These results suggest that rice drinks fermented with Lactiplantibacillus Plantarum JSA22 ameliorate the severity of DSS-colitis, by potentially reducing proinflammatory cytokines.

Occurrence of process environment changes, such as influent load variances and process condition changes, can reduce treatment efficiency, increasing effluent water quality. In order to prevent exceeding effluent standards, it is necessary to manage effluent water quality based on process operation data including influent and process condition before exceeding occur. Accordingly, the development of the effluent water quality prediction system and the application of technology to wastewater treatment processes are getting attention. Therefore, in this study, through the multi-channel measuring instruments in the bio-reactor and smart multi-item water quality sensors (location in bio-reactor influent/effluent) were installed in The Seonam water recycling center #2 treatment plant series 3, it was collected water quality data centering around COD, T-N. Using the collected data, the artificial intelligence-based effluent quality prediction model was developed, and relative errors were compared with effluent TMS measurement data. Through relative error comparison, the applicability of the artificial intelligence-based effluent water quality prediction model in wastewater treatment process was reviewed.

For motor controller designers, building a simulation environment is not a difficult process. After verifying the controller by simulation, it is common to select 20kHz for the current control loop, 1kHz for the speed loop, and 100Hz for the position loop when implementing the actual HW embedded system. This is because maximized cycles (20kHz) for each control loop are unnecessary in control theory and are a waste of cost and HW resources. However, in a simulation environment, each loop will often have the same control cycle (20kHz maximum). This is because we think it is unnecessary to reflect this part in the simulation. In this paper, it is shown that the difference in the sampling time of each control loop makes a big difference in the simulation result, and as a solution, it is proposed to apply LPF to the position loop output stage. In the process, the reasons for the differences were analyzed, and the effect of LPF, the reason for application, and the feasibility of implementation were proved by actual software coding.

본 연구의 목적은 한탄강 세계지질공원 연천 지역의 “자기-안내식 해설” 매체가 방문객이 이해하기 쉽고 배경 지식수준에 맞춰 작성되어 있는지 탐색하는 것이다. 이를 위해, 2022년 9월과 11월 2차례에 걸쳐 한탄강 세계지질공원 을 현장 조사하고, 지질명소의 형성 시대와 지질 특성이 다양한 연천 지역을 분석 대상으로 선정하였다. 연천 지역에 존재하는 총 36개의 자기-안내식 해설 매체를 대상으로 지질명소별 해설 매체의 현황, 이독성 수준, 그래픽의 특성, 과 학과 교육과정 반영 정도를 분석하였다. 연구 결과, 연천 지역 해설 매체 종류는 안내판이 가장 많고, 지질명소를 안내 한 내용이 주를 이루었다. 해설 매체 텍스트의 분량은 12학년 과학 교과서보다 많고, 평균 어휘 등급은 11-12학년군 과 학 교과서 수준과 유사하고, 복문의 비율이 높아 이독성이 다소 낮았다. 해설 매체에 포함된 그래픽의 종류는 사진이 가장 많고, 대부분 예시적 기능이며, 다중 구조 그래픽이 사용되어, 지질 형성 과정을 이해하는 데 도움을 주었다. 해설 매체에서 사용하는 과학 용어 중 86.3%가 2015 개정 교육과정의 “고체지구” 영역에 포함된 용어를 사용하였으며, 교육 과정에 포함된 과학 용어는 4학년 수준의 용어가 가장 많았다. 선택 교육과정인 11학년 수준의 용어가 두 번째로 많고, 전체 과학 용어 중 13.7%는 교육과정에 포함되어 있지 않은 용어였다. 또한, 지질명소에 따라 해설 매체에 사용된 과 학 용어 수준 차이가 나타났으며, 특히 안내판보다 홈페이지에 사용된 용어 수준이 일반적으로 높은 경향을 보였다. 본 연구 결과를 통해 연천 지역의 지질명소별 해설 매체에 따라 방문객 스스로 이해하는 데 어려움을 주는 요인을 구체적 으로 파악할 수 있었다. 일반 관람객의 지질자원 교육을 활성화하고 지질학 분야의 발전을 기대할 수 있는 자기-안내식 해설 매체의 개선 방향에 대한 후속 연구를 제언하였다.

This study was performed to investigate antioxidant and anti-inflammatory activities of perilla(Perilla frutescens L.) seed, flower and leaf according to extraction condition. Perilla seed extracts(PSE), perilla flower extracts(PFE), perilla leaf extracts(PLE) was extracted by stirring extraction (STE, 25°C), shaking extraction (SHE, 80°C), and sonication assisted extraction(SAE, , 25°C) with 94% ethanol, 60% ethanol and distilled water, followed by analysis of total polyphenol and flavonoid and testing radical scavenging activities. The highest total polyphenol content (5.47, 9.36, 38.58 mg gallic acid equivalent/g), total flavonoid content(5.77, 8.62, 46.44 mg catechin equivalent/g), ABTS(10.68, 19.46, 63.56 mg trolox equivalent/g) and DPPH(6.51, 7.69, 79.73 mg trolox equivalent/g) radical scavenging activity of PSE, PFE and PLE was observed in the HWE with 60% ethanol,. Among the three extraction method, SHE provided the best results for yield, polyphenol, flavonoid content of perilla seed, flower, leaf in comparison to STE or SAE. SHE with 60% ethanol of perilla seed, flower, leaf more effectively inhibited secretion of nitric oxide(NO) and pro-inflammatory cytokine in RAW 264.7 macrophage exposed to LPS compared to other extraction solvent and method. Therefore, these extracts obtained from perilla seed, flower, leaf could be used antioxidant and anti-inflammatory ingredients in the food industry.

Highly safe lithium-ion batteries (LIBs) are required for large-scale applications such as electrical vehicles and energy storage systems. A highly stable cathode is essential for the development of safe LIBs. LiFePO4 is one of the most stable cathodes because of its stable structure and strong bonding between P and O. However, it has a lower energy density than lithium transition metal oxides. To investigate the high energy density of phosphate materials, vanadium phosphates were investigated. Vanadium enables multiple redox reactions as well as high redox potentials. LiVPO4O has two redox reactions (V5+/V4+/V3+) but low electrochemical activity. In this study, LiVPO4O is doped with fluorine to improve its electrochemical activity and increase its operational redox potential. With increasing fluorine content in LiVPO4O1-xFx, the local vanadium structure changed as the vanadium oxidation state changed. In addition, the operating potential increased with increasing fluorine content. Thus, it was confirmed that fluorine doping leads to a strong inductive effect and high operating voltage, which helps improve the energy density of the cathode materials.

High-entropy alloys (HEAs) are characterized by having five or more main elements and forming simple solids without forming intermetallic compounds, owing to the high entropy effect. HEAs with these characteristics are being researched as structural materials for extreme environments. Conventional refractory alloys have excellent hightemperature strength and stability; however, problems occur when they are used extensively in a high-temperature environment, leading to reduced fatigue properties due to oxidation or a limited service life. In contrast, refractory entropy alloys, which provide refractory properties to entropy alloys, can address these issues and improve the hightemperature stability of the alloy through phase control when designed based on existing refractory alloy elements. Refractory high-entropy alloys require sufficient milling time while in the process of mechanical alloying because of the brittleness of the added elements. Consequently, the high-energy milling process must be optimized because of the possibility of contamination of the alloyed powder during prolonged milling. In this study, we investigated the hightemperature oxidation behavior of refractory high-entropy alloys while optimizing the milling time.

본 연구는 전문가 기반형 모델(Habitat Suitability Index)의 한계로 지적되는 주관적 기준, 통계분석의 부재 등과 통계기반형 모델(MaxEnt)의 한계로 지적되는 현장검증, 전문가 의견 반영 등의 극복을 위하여 각각의 모델을 개발하여 통합하는 방식으로 핵심서식지를 도출하였다. 핵심서식지 발굴을 위해 문헌분석 및 공간분석자료를 바탕으로 전문가 심층면담을 진행하였고, 전문가 자문과 GIS 도면 구축 가능성을 고려하여 모델을 개발하였다. 주요 환경변수는 식생대, 임상, 임분밀도, 연평균 강수량, 유효토심으로 선정되었다. 그 결과 현재 나도승마가 분포하고 있는 16지점 중 15지점이 핵심서식지로 나타났으며, 개발된 모델은 약 93.75%의 높은 정확도를 가지고 있는 것으로 나타났다. 하지만 전체 연구대상지의 약 27.8%가 핵심서식지로 나타남에 따라, 추후 서식변수 및 공간자료 정밀화를 통한 모델의 고도화가 필요할 것으로 판단된다. 따라서 높은 등급으로 확인된 서식지라도 대상종의 서식유무 파악을 위한 현장검증은 필수적으로 수행되어야 한다. 하지만, 이러한 한계에도 불구하고 HSI와 MaxEnt의 상호보완적 활용은 생물종의 분포와 서식지 이용 특성을 통하여 적합 서식지를 예측하고, 신규 서식지 발굴 및 대체서식지 선정 등 다양한 방면으로 활용 가능할 것으로 판단된다.

This study was undertaken to provide basic data to aid product development and marketing by identifying purchasing behaviors and performing Important Performance Analysis (IPA) according to the consumption values of rice cakes. This study was conducted on 426 consumers who purchased rice cakes. Analysis was performed to determine general characteristics, consumption behaviors, preference for rice cakes, material preferences for rice cake development, need for rice cake development, and importance and satisfaction when selecting rice cakes. Cluster analysis classified consumption values into three clusters. The high and middle consumption value groups contained the greatest proportions of consumers aged over fifty. The high and medium consumption value groups preferred rice cakes more than the low consumption value group. Higher rice cake consumption value was positively associated with the greater preference for rice cakes. Furthermore, the perceived need to develop rice cakes was greatest in the high consumption value group. In addition, importance and satisfaction were positively associated with consumption value. IPA analysis showed that the attributes that require continuous attention because of their contributions to importance and satisfaction were taste, quantity, and hygiene. Different rice cake marketing and product development strategies are required for different consumption values.

본 논문에서는 기저 스크리닝 기반 크리깅 모델(BSKM: Basis Screening based Kriging Model) 생성의 정확도를 높이기 위해 페널티 를 적용한 최대 우도 평가 방법(PMLE : Penalized Maximum Likelihood Estimation)에 대해서 소개한다. BSKM에서 사용하는 기저함 수의 최대 차수와 종류는 그 중요도에 따라서 결정하게 되며, 이때 중요도의 지표는 기저함수에 대한 교차 검증 오차(CVE : Cross Validation Error)로 택한다. 크리깅 모델(KM : Kriging Model) 구성시 최적의 기저함수 조합은 우선 최대 기저함수 차수를 선택하고 개별 기저함수의 중요도를 평가를 하게 된다. 최적 기저함수 조합은 크리깅 모델의 CVE가 최소가 될 때까지 개별 기저함수의 중요도 가 높은 순으로 기저함수를 하나씩 추가하며 찾는다. 이 과정에서 KM은 반복적으로 생성해야 하며, 동시에 데이터 사이의 상관관계 를 나타내는 하이퍼 매개변수(Hyper-parameters)도 최대 우도 평가방법을 통해 계산하여야 한다. 하이퍼 매개변수의 값에 따라 선택 되는 최적의 기저함수 조합이 달라지기 때문에 KM의 정확도에 막대한 영향을 미치게 된다. 정확한 하이퍼 매개변수를 계산하기 위해 서 PMLE 방법을 적용하였으며, Branin-Hoo 함수 문제에 적용하여 BSKM 의 정확성이 개선될 수 있음을 확인하였다.

PURPOSES : This study is to evaluate environmental improvement effects of underground road project, as a case study of ‘Seobu’underground expressway project in Korea. METHODS : The environmental improvement effects of underground road construction were classified into tree sector in this study – air quality, noise, and thermal environment. To evaluate these effects, this study collected and divided environment dataset into before, during, and after ‘Seobu’underground expressway construction, and compared the change of values with entire city. In addition, the quantification method of environmental improvement effects was suggested based on the literature review. RESULTS : The result of this study indicates that there exist significant improvement effects of urban environment after the construction of ‘Seobu’underground expressway. Specifically, the concentration of particulate matters (PM10) and daytime/nighttime noise, and land surface temperature (LST) were improved along the expressway. In addition, the overall environmental benefit of ‘Seobu’ underground expressway was estimated to 1.15 billion won per year. CONCLUSIONS : To promote systematic and consistent underground road project, it is required to establish legislative system for evalauting and supporting urban improvement effects.

Dissolved organic matter (DOM) is a key component in the biogeochemical cycling in freshwater ecosystem. However, it has been rarely explored, particularly complex river watershed dominated by natural and anthropogenic sources, such as various effluent facility and livestock. The current research developed a new analytical method for TOC/TN (Total Organic Carbon/Total Nitrogen) stable isotope ratio, and distinguish DOM source using stable isotope value (δ13C-DOC) and spectroscopic indices (fluorescence index [FI] and biological index [BIX]). The TOC/TN-IR/MS analytical system was optimized and precision and accuracy were secured using two international standards (IAEA-600 Caffein, IAEA-CH-6 Sucrose). As a result of controlling the instrumental conditions to enable TOC stable isotope analysis even in low-concentration environmental samples (<1 mgC L-1), the minimum detection limit was improved. The 12 potential DOM source were collected from watershed, which includes top-soils, groundwater, plant group (fallen leaves, riparian plants, suspended algae) and effluent group (pig and cow livestock, agricultural land, urban, industry facility, swine facility and wastewater treatment facilities). As a result of comparing characteristics between 12 sources using spectroscopic indices and δ13C-DOC values, it were divided into four groups according to their characteristics as a respective DOM sources. The current study established the TOC/TN stable isotope analyses system for the first time in Korea, and found that spectroscopic indices and δ13C-DOC are very useful tool to trace the origin of organic matter in the aquatic environments through library database.