The semiconductor and display industries require the development of plasma resistant materials for use in high density plasma etching process equipment. Yttria (Y2O3) is a ceramic material mainly used to ensure good plasma resistance properties, which requires a dense microstructure. In commercial production, a sintering process is applied to reduce the sintering temperature of Y2O3. In this study, the effect of the addition of glass frit to the sintered specimen was examined when manufacturing yttria sintered specimens for semiconductor process equipment parts. The Y2O3 specimen was shaped into a Ø50 mm size and then sintered at 1,600 °C for 1~8 h. The characteristics, X-ray diffraction pattern, densities, contraction rate of the specimen, and swelling of the surface of the Y2O3 specimens were investigated as a function of the sintering time and glass frit addition. The Y2O3 specimen exhibited a density of over 4.9 g/cm3 as the sintering time increased, and the swelling phenomenon characteristics were improved by glass frit, by controlling particle size.

The purpose of this study is to analyze the correlation between ecotoxicity and water quality items using Daphnia magna in public sewage treatment plant process and to obtain operational data to control ecotoxicity through research on removal efficiency. The average value of ecotoxicity was 1.39 TU in the influent, 1.50 TU in the grit chamber, and 0.84 TU in the primary settling tank and it was found that most organic matters, nitrogen, and phosphorus were removed through biological treatment in the bioreactor. Using Pearson’s correlation analysis, the positive correlation was confirmed in the order of ecotoxicity and water quality items TOC, BOD, T-N, NH3-N, SS, EC, and Cu. As a result of conducting a multilinear regression analysis with items representing positive correlation as independent variables, the regression model was found to be statistically significant, and the explanatory power of the regression model was about 81.6%. TOC was found to have a significant effect on ecotoxicity with B=0.009 (p<.001) and Cu with B=16.670 (p<.001), and since the B sign is positive (+), an increase of 1 in TOC increases the value of ecotoxicity by 0.009 and an increase in Cu by 1 increases the value of ecotoxicity by 16.670. TOC (β=0.789, p<.001) and Cu (β=0.209, p<.001) were found to have a significant positive effect on ecotoxicity. TOC and Cu have a great effect on ecotoxicity in the sewage treatment plant process, and it is judged that TOC and Cu should be considered preferentially and controlled in order to efficiently control ecotoxicity.

PURPOSES : This study presents a general guideline for the initial management of traffic signal timings in response to traffic incidents, prior to the implementation of specific treatments in detail. The proposed solution includes a set of optimal reductions in the green time rates at three signalized intersections upstream. METHODS : To account for the various traffic and incident conditions that may be encountered, a total of 36 traffic-condition scenarios were prepared. These scenarios encompass a wide range of conditions, from unsaturated to near-saturated conditions, and were designed to provide a comprehensive understanding of the impact of traffic conditions on signal timing. For each of the traffic conditions, all 27 traffic signal timing combinations were subjected to testing. A total of 972 simulation analyses were conducted using the SUMO model. The results indicated that the scenario with the lowest control delay was the optimal choice. RESULTS : The results indicated that the most effective initial management for the traffic incident would be to reduce the green signal timings by 20% at the first two upstream intersections and by 40% at the third intersection. CONCLUSIONS : We propose reducing the green times by 20% at the first and second intersections and by 40% at the third intersection as the initial response of the traffic signal control center when a traffic incident occurs.

This study examined the spatial morphological patterns of forest habitats and the characteristics of roadkill occurrences in the forests of Mungyeong, Yecheon, Yeongju, Andong, and Bonghwa in Gyeongsangbuk-do. It involved building a resistance map between habitats and analyzing connectivity based on the least-cost distance. The analysis of the distance between the forest habitat Cores derived from MSPA and roadkill points showed that roadkill occurrences were concentrated approximately 74.11 m away from the Cores, with most roadkills happening within 360 m from the habitats. The connectivity analysis between core habitats larger than 1 km2 revealed 141 core habitats and 242 least-cost paths between them. The corridor distance value was found to be highest in Mungyeong city, indicating an urgent need for strategies to enhance habitat connectivity there. This research is expected to serve as foundational data for developing strategies to enhance ecosystem connectivity and restore habitats, by analyzing ecosystem connectivity and roadkill issues due to habitat fragmentation.

Supplementing feed components is becoming increasingly difficult for various reasons, including increased shipping costs, decreased capture efficiency, and global warming. For this reason, much research has been conducted globally to find alternative protein sources. The black soldier fly (BSF; Hermetia illucens) is an important feed item for nutritional accumulation and has environmental consequences. Few studies have been conducted to determine the nutritional level of the substrate, but most of these studies have involved modifying the substrate material. The aim of this study was to determine the ideal crude protein(CP) content of a substrate for BSF rearing. The experimental treatment was separated into three CP levels (low, 13.5%; medium, 20%; high, 26.5%) in the substrate. The results showed that the BSF weight (6.46%) and protein conversion ratio (1.13%) increased as the substrate CP level increased (p<0.05). In addition, protein (14.38%) and lipid (13.12%) yields were significantly increased (p<0.05). The BSF CP level increased as the substrate CP level increased (p<0.05). CP levels in the substrate upregulated the levels of certain fatty acids, essential amino acids, and non-essential amino acids (p<0.05). In conclusion, the potential values of BSF as feed were improved as the CP level of the substrate increased; However, no difference was found between medium and high CP levels in the rearing substrate. These results suggested that the substrate CP level should be at the medium level for optimal product quality. In conclusion, BSF quality is influenced by substrate nutrient levels, necessitating the development of specialized substrates for effective rearing.

For sustainable livestock industry, black soldier fly as eco-friendly animal protein source is spotlighted for swine and poultry. However, most of black soldier fly is reared in dirty condition like food waste. In this study, we investigated the effects of fiber level on the growth performance and nutrient composition of black soldier fly reared in specific substrate. Treatments were divided in two as Low (fiber level: 7.1%), and High (fiber level: 14.2%) with a total of 50,000 eggs each. The rearing box had a dimension with 1064 × 507 × 320 cm (length × width × height). Black soldier fly survival rate (72.24 vs. 76.48) and substrate consumption (77.43 vs. 80.37) were greater in High than Low. However, bioconversion (10.59 vs. 9.80) and protein conversion (8.97 vs. 8.00) were increased in Low than High. Gross energy was higher in High compared with Low (4,133 vs. 4,208). Some of essential amino acid (Isoleucine, leucine, phenylalanine, threonine, tryptophan) were significantly higher in High compared with Low, and non-essential amino acid (alanine, aspartate, glycine, proline, serine, tyrosine) were higher in High compared with Low. Acids such as C12:0, C14:0, C15:0, and C20:1 were higher in High compared with Low, while C18:4 was higher in Low compared with High. As a result, black soldier fly reared in high fiber substrate might be a preferred option for rearing and producing a reliable animal protein source for monogastric animal.

해상풍력자원지도는 풍력발전사업, 국가 재생에너지 공급 정책, 전력계통망 계획의 핵심자료이다. 본 연구에서는 풍력자원 해석기술의 개발 동향을 검토하고 시사점을 논의하였다. 국가별 해상풍력자원지도 개발하여 활용하고 있는 대표적인 국가는 유럽연합 (덴마크), 미국, 그리고 일본이며, 이들을 중심으로 풍력자원지도 생산 기술 및 활용 현황을 분석하였다. 기본적으로 풍력자원지도의 품 질 향상을 위해 수치해석 기술을 업그레이드 해오고 있다. 이들의 개발 전략은 앙상블 중규모 수치해석과 중규모-미세규모 모델의 커 플링이었고 그 외 모델내 물리해석기법들의 적용은 지역마다 다른 것으로 확인되었다. 따라서 최근 진보된 수치모델을 도입하고 우리 나라 풍황 특성을 고려하여 최적의 실험디자인을 도출해야 할 것으로 보인다. 특히 300 m부근의 대기경계층에서의 연직고도의 상세 한 반영은 공통점으로, 이는 대형화된 풍력터빈을 고려하여 최적의 풍력발전소 후보지 발굴에 적합하도록 장기간의 풍황정보를 정확 하게 제공하기 위한 제안사항인 것으로 보인다.

2023년 경상남도 함안 소재 재배중인 팥의 땅가 줄기에서 흰비단병 증상이 발생하였다. 병징은 팥의 땅가 줄기 아랫부분에 수침상 현상을 보이다가 이후 물러지고 부패되어 서서히 시들어 포기 전체가 말라 죽었다. 땅가 줄기에서 병반부와 토양 표면에 흰색의 곰팡이가 발생하였고 갈색의 작은 둥근 균핵이 많이 형성되었다. 순수 분리 및 배양을 통해 얻은 곰팡이는 감자한천배지에서 흰색을 띈 매끈한 비단결 균사를 잘 뻗었고 균총 위에 갈색의 작은 둥근 균핵을 많이 형성하였다. 균핵의 크기는 1-3 mm이고 균사의 폭은 4-9 μm였다. 또한 균사에서 clamp connection이 관찰되었다. 병원성 검정을 통해 최초 포장에서 발견한 동일한 병징이 발달하였고 코흐의 가설에 근거한 재분리를 수행하였다. 곰팡이를 처리하지 않은 팥에서는 병징이 발달하지 않았다. 원인 곰팡이의 동정을 명확하게 위해 ITS rRNA 영역 염기서열 및 유전적 유연관계를 분석하였다. 또한 종-특이적 PCR 검정을 수행하여 팥에 발생한 흰비단병 증상의 원인 곰팡이를 Athelia rolfsii로 동정하였다. 본 연구는 국내 팥 흰비단병의 최초 보고이다. 또한, 흰비단병의 발생은 국내 팥 생산에 큰 위협이 될 수 있을 것이고 본 연구는 향후 팥 흰비단병 방제를 위한 전략 수립에 기초자료로 사용되리라 여겨진다.

This study analyzes the impact of import country environments on Korean fishery exports. To achieve the research objective, focusing on trade facilitation and import market aspects, the import country environment was modeled and analyzed by panel gravity analysis technique. In the basic export model considering only the trade facilitation aspect, agriculture and institutional factors had a significant impact on Korean fishery exports. However, when considering both trade facilitation and import market aspects, it was found that import market aspect had a greater influence on Korean fishery exports than trade facilitation aspect. Specifically, the import market factor that had the most positive impact on Korean fishery exports was the GDP of the import country. GDP, representing the economic scale of the country, indicates consumer purchasing power through per capita GDP. Hence, a higher GDP level implies a higher consumer purchasing power, suggesting a higher potential consumption of fishery products. The second positive factor influencing Korean fishery exports was food imports in the import country. Therefore, to expand Korean fishery exports, it is essential to target countries with high levels of GDP and food imports. Conversely, factors negatively affecting Korean fishery exports were merchandise imports and population in the import country. Therefore, countries with high levels of these negative factors should be managed as demarketing targets. Additionally, trade facilitation variables, which have relatively smaller influence, such as transparency and institutions, also significantly impact Korean fishery exports. While transparency has a positive effect, institution has a negative effect. Thus, to expand Korean fishery exports, strategies should focus on countries with high transparency and less stringent institutional regulations.

This study investigated the species composition and community structure of aquatic organisms captured using coastal beam trawling in Gomso Bay, Jeollabuk-do, from January to December 2022. Throughout the experimental period, a total of 20,246 individuals belonging to 94 marine species were captured, with a combined biomass of 602,828 g. Fish exhibited the highest abundance, comprising 56 species, followed by crustacea (21 species), bivalvia (8 species), cephalopoda (5 species), gastropoda (3 species), and holothuroidea (1 species). The dominant species was Leiognathus nuchalis, constituting 14.0% of the total individuals, followed by Portunus trituberculatus at 12.1%, Oratosquilla oratoria at 10.4%, Crangon hakodatei at 9.9%, and Metapenaeus joyneri at 7.9%. The diversity index ranged from 1.72 to 2.55, with the lowest diversity observed in March and the highest in July. Cluster analysis based on species composition of the 27 most common species showed that aquatic organisms were divided into three groups: spring and summer organisms (Group A) and summer organisms (Group B) and autumn and winter organisms (Group C).

본 연구는 1960년대에 향수(Nostalgia) 주제를 가진 트로트 곡의 특징을 연구하였다. 1960년대 트로트 가사가 고향에 대한 향수를 어떤 방식으로 다뤘으며, 해당 트로트 가사가 의미하는바가 무엇인지를 고찰하였다. 그리고 고향에 대한 그리움과 회상을 표현하는 가사 속 단어들 및 타향을 부정하는 단어들 속에 내재된 감정을 분석하였다. 본 연구는 트로트 곡에서 드러나는 고향에 대한 향수에 관한 내용의 가사를 분석함으로써, 가사 분석의 다양성을 고찰하는 것에 목적을 두고 있 다. 1960년대 트로트 가사에는 고향에 대한 그리움과 회상 그리고 가족과 연인에 대한 사랑이 주 로 나타났으며 한국적 정서가 드러나는 시대를 반영한 이야기들을 표현한 단순 명료한 가사로 이 루어져있었다. 또한 1970년대에는 추상적인 이별이야기를 담는데 주력하는 양상을 보인 반면, 1960년대에는 직접적인 단어로 표현함으로써 곡의 애절함과 씁쓸함이 보다 더 잘 드러났으며 대중 들 기억에 남는 가사로 공감을 더했다. 대중가요에서 고향을 주제로 한 가사에서는 사람의 감성을 움직이게 하며 향수를 불러일으키지만 시대적 배경과 대중들의 상황과 상태, 염원을 분석한다면 가사에 담긴 함의를 구체적으로 파악할 수 있으며 많은 창작자들이 가사를 분석하는 것에 도움이 될 것이라고 예상한다.