This study analyzes the aerodynamic and structural characteristics of an H-Darrieus vertical-axis wind turbine (VAWT) under varying inlet velocities using transient analysis. The k-ε turbulence model and six-DOF were applied to simulate urban environments in the flow analysis, while the structural analysis considered blade momentum of inertia and RPM conditions. The numerical results showed that the drag and lift forces increased by 60% and 53% respectively from the nominal wind speed to the cut-off wind speed conditions. Structural analysis indicated that the maximum Von-Mises stress in the blade did not exceed the yield strength of 69 MPa of PC-ABS, ensuring structural stability. However, the connecting rod exceeded the yield strength of SPCC 270 MPa, suggesting potential failure due to repeated rotational loads. This study confirms that materials with a yield strength of more than 1,100 MPa required for connecting rods to ensure reliable operation at high wind speed. These findings provide important insights for the design of robust VAWTs suitable for extreme environments.
본 연구는 명대(明代) 소설 금병매(金甁梅)의 주요인물인 반금련(潘金蓮)을, 19세 기 독일 철학자 프리드리히 니체(Friedrich Nietzsche)의 철학적 관점에서 재해석하 고자 한다. 니체가 살았던 시대와 반금련이 살았던 시대는 초월적 가치가 중시되던 과거에서 벗어나 개인에게로 관심이 옮아가던 시대라는 공통점이 있다. 개인의 욕망 과 개인의 육체에 관심을 갖던 시대적 유사성에 근거하여 니체의 철학적 개념, 특히 ‘노예 도덕’, ‘힘에의 의지(Will to Power)’, ‘위버멘쉬(Übermensch)’ 개념을 중심으로 반금련의 행동과 욕망을 분석해보았다. 연구 결과, 반금련의 행동은 전통 봉건질서에 순응하지 않고 자신의 삶을 개척하려는 주도적 면모를 보였다. 또 그녀의 욕망에 대한 강렬한 에너지과 열정은 니체의 ‘힘에의 의지’ 개념을 통해 자신의 잠재력을 최대 한 실현하고 환경을 지배하고자 하는 근본적인 생명력의 표현으로 해석할 수 있다. 그러나 이러한 새로운 해석에도 불구하고 그녀가 비극적 결말을 맞을 수밖에 없는 것은 그녀 자신의 한계 때문이다. 이는 니체의 위버멘쉬 개념을 통해 해석할 수 있 다. 그녀는 욕망을 적극적으로 추구했지만 이는 진정한 자기 결정에 의한 것이 아니 며 단순한 쾌락 추구에 그쳤다. 또 기존 질서에 도전했지만 새로운 가치를 창조하지 도 못했다. 그녀의 행동은 파괴적이었을 뿐 건설적인 대안을 제시하지 못했다는 점 에서 한계를 보였다. 니체의 관점을 통해 반금련의 욕망과 행동을 해석하는 것은 단 순히 ‘선’과 ‘악’을 기준으로 그녀를 판단하는 것을 넘어서 한 인물의 근원적 동기와 내면의 욕구를 더 깊이 이해할 수 있다는 점에서 의의를 가진다.
This study was conducted to efficiently manage THC, which was previously managed only through self-measurement. Using Selected Ion Flow Tube Mass Spectrometers, a real-time air quality measurement device, VOCs were measured in five industrial complexes, and methyl ethyl ketone was measured at the highest concentration in the industrial complexes. THC measurements were conducted at business sites located in the area. As a result of the measurements, printing processes, drying processes, etc. exceeded the emission standard of 110 ppm in three processes, and the outlets that exceeded the emission standard were instructed to improve prevention facilities such as activated carbon replacement, thereby reducing highconcentration VOC emissions. The results of the study suggest that if inspection agencies measure VOCs in real time and conduct Total Hydro Carbon measurements, etc. mainly in high-concentration areas, VOCs and Total Hydro Carbon, which are the causes of greenhouse gases and odors, can be efficiently reduced.
This study examined the spatiotemporal changes in Jilnal Wetland using satellite image-based time series data and field surveys. The analysis focused on changes in open water surface area and vegetation using the JRC Surface Water Monthly Water History dataset and Landsat imagery from 1984 to 2020. The impact of hydrological changes on vegetation was assessed through surveys conducted before and after the 2023 monsoon season. Results indicated a continuous decrease in open water surface area since the 1980s, with a sharp decline post-2003. NDVI analysis showed an inverse relationship between water area reduction and increased vegetation vigor and coverage. Field surveys revealed that hydrological changes directly affected vegetation structure, leading to new herbaceous communities and greater diversity post-monsoon. These findings highlight significant ecosystem changes driven by anthropogenic factors and natural succession, necessitating a comprehensive conservation strategy, including development control, hydrological management, terrestrialization prevention, and long-term monitoring.
본 연구에서는 20대 대학생들을 대상으로 사회부과 완벽주의와 우울 간의 관계에서 정서적 탈진의 매개효과를 검증하였고, 이에 더하여 성별에 의한 조절효과를 확인하였다. 총 602명의 자료를 분석한 결과, 사회부과 완벽주의 성향이 정서적 탈진 및 우울을 각각 유의하게 예측하였고, 정서적 탈진 역시 우울 정도를 예측하였다. 이어서, 사회부과 완벽주의 성향이 우울을 예측하는 데 있어 정서적 탈진의 매개효과가 유의한 것으로 검증되었고, 여기에 성별 에 의한 조절효과도 있는 것으로 확인되었다. 즉, 사회부과 완벽주의와 우울의 관계에서 정서적 탈진이 매개할 때 남성보다 여성에게서 더 높은 우울 수준이 관찰되었다. 본 연구는 대학생의 주요 과제인 학업의 부담에 따라 나타날 수 있는 정서적 탈진 및 정신건강과 관련된 연구모형의 제시와 검증을 수행하였고, 그에 따른 개입 및 개선 방안의 필요성을 제안하였다.
This study was conducted to solve the problem of the existing odor management method taking a long time to analyze samples. Using real-time air quality measurement equipment, 17 designated odor substances were measured three times at a business site causing odor complaints. As a result, three substances, hydrogen sulfide, trimethylamine, and methyl mercaptan, were measured at higher levels than the site boundary emission standards inside the business site. In the case of trimethylamine, it was measured about 500 times higher than Odor Threshold Values, and was estimated to be the substance causing the odor. Through an inspection of the business site, improvements were instructed to be made to the wastewater treatment process, which is the emission facility where trimethylamine is generated. Subsequent measurement results showed that designated odor substances were measured within the emission standards at all locations, and it was determined that efficient management of odorgenerating businesses would be possible if Selected Ion Flow tube-Mass Spectrometry was utilized.
In this study, numerical analysis was performed on a type IV hydrogen storage tank to analyze the temperature change of hydrogen inside the tank and the filling performance by changing the inlet nozzle outlet angle and the number of outlets. Considering the residual state of charge (SOC) inside the initial tank, the initial pressure was 10 MPa, and the temperature of hydrogen inside the tank and the SOC results were analyzed when hydrogen with a temperature of 233 K was introduced under the conditions of liner, wrap, and outside temperature of 298 K. The results of the analysis showed that the charging completion rate reached the charging limit pressure. The analysis showed that time of filling completion, when the filling limit pressure is reached, the SOC result is about 94% for all geometry change conditions, and the filling completion time increases by 5s as the number of outlets decreases. The temperature change of the wrap area at the end of filling is up to 3.6K, which shows that the outside air temperature has a negligible effect on the hydrogen temperature change inside the tank.
The practice of paying for meals in a society is a social behavior that reflects the culture of that society. Accordingly, this study examined Koreans' way to pay for meal and perception of that meal payment methods in various contexts. In Study 1 and 2, Korean college students were asked open-ended questions about the payment methods that Koreans prefer in various situations, and asked to describe reasons for liking or disliking 9 payment methods derived by study 1. As a result, positive characteristics stood out as fairness such as rationality and fairness, as well as intimacy such as friendliness, affection. In Study 3 and 4, we investigated the perception of 6 payment methods (equal payment, membership dues payment, rotational payment, hierarchical payment, ability payment, and volunteering payment method) and examined whether there were generational differences in preferences for six payment methods depending on the situation. As a result, each payment method could be classified into a payment method closer to the logic of reason (sari), which emphasizes fairness, and the logic of heart (simjung), which emphasizes emotional intimacy. Payment method closer to fairness (equal method) was consistently preferred by young people. These results were discussed focusing on the cultural characteristics of Korean society.
This study aims to examine how the Gyeongseong Hokuk Shrine established the natural environment in Yongsan during the Japanese colonial period, focusing on the relationship between Japan and Chosen Hokuk Shrines. In the colonies, the establishment of shrines strongly tended to symbolize Imperial Japan and visually represent its ruling logic. The Gyeongseong Hokuk Shrine holds historical significance as a place to commemorate soldiers who died for the Emperor and as a tool of colonial rule, but further discussion is needed on how it was organized within the Yongsan. This study focuses on Hokuk Shrine planning under which the Shrine Bureau of Home Ministry constructed similar shrines across Japan by the Ministry of Home Affairs Ordinance No. 12 of 1939. As a result, this study examines the environment and architectural styles of Hokuk Shrines through examples from Japan and uses this analysis to explore the characteristics of Gyeongseong Hokuk Shrine and its relationship with the Yongsan. The significance of this research lies in highlighting the historical urban significance of Yongsan during the modern period.
In the seismic evaluation of underground utility tunnels, selecting an analytical method is critical to estimating reasonable seismic responses. In simplified pseudo-static analysis methods widely applied to typical seismic design and evaluation of underground tunnels in practice, it is essential to check whether the methods provide valid results for cut-and-cover tunnels buried in shallow to medium depth. The differences between the two simplified pseudo-static methods are discussed in this study, and the analysis results are compared to those obtained from FLAC models. In addition to the analysis methods, seismic site classification, overburden soil depth, and sectional configuration are considered variables to examine their effects on the seismic response of underground utility tunnels. Based on the analysis results, the characteristics derived from the concepts and details of each simplified model are discussed. Also, general observations are made for the application of simplified analysis methods.
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.
유통 중인 생분해성 합성수지로 만들어진 식품용 기구 및 위생용품 50건을 대상으로 ‘식품용 기구 및 용기·포장 공전’의 기준·규격을 검사하였다. PLA 재질의 유아식기 1 건에서 ‘과망간산칼륨소비량’이 20mg/L으로 기준치(10 mg/ L 이하)를 초과하였고, 그 외 모든 시료에서는 포름알데히 드, 납, 비소 등이 기준·규격 이하로 안전한 수준이었다. 또한 가정에서 유아식기를 소독하는 방법의 안전성을 조 사하기 위해, PLA 재질의 유아식기(n=21)에서 반복적인 열탕소독과 자외선 조사에 따른 이행량의 변화를 조사하였다. 반복적인 열탕소독이 자외선 조사에 비해 포름알데 히드와 비소의 이행량이 많았으나, 이행량은 매우 낮은 수 준이었다. 그리고 유아(만 1-3세) 기준으로 계산한 포름알 데히드와 비소의 일일추정섭취량(EDI)은 최대 6.0×10-4mg/ kg b.w./day 및 1.3×10-1 μg/kg b.w./day였으며, 이는 일일섭 취한계량(TDI, 0.15 mg/kg b.w./day) 및 잠정주간섭취허용 량(PTWI, 9.0 μg/kg b.w./week)의 0.40% 및 10.42%로 낮 은 수준임을 확인하였다. 따라서 현 국내에서 유통되고 있 는 식품용 생분해성 합성수지제는 안전한 수준임을 확인 하였다.