This study investigated the seasonal variations and environmental factors influencing soil respiration in Quercus mongolica forests at three distinct sites in South Korea: Mt. Jeombongsan, Mt. Namsan, and Mt. Jirisan. Monthly soil respiration rates were measured from 2009 to 2010 using a closed chamber method, alongside assessments of soil temperature, moisture, and organic matter. Results revealed significant seasonal and spatial variability, with the highest respiration rates recorded during summer months. Soil temperature was identified as the primary driver of respiration, showing strong positive correlations across all sites (R2=0.64 - 0.88). The temperature sensitivity (Q10) values ranged from 2.7 at Mt. Namsan to 5.7 at Mt. Jeombongsan, underscoring the heightened vulnerability of cooler, high-altitude forests to warming. Soil moisture had a dual role, promoting respiration at moderate levels but inhibiting it under saturated conditions, particularly at Mt. Jirisan. Soil organic matter content exhibited an inverse relationship with respiration rates, indicating that substrate quality, rather than quantity, predominantly governs microbial activity. Plant-soil interactions, including root respiration and litterfall decomposition, further modulated respiration patterns, with site-specific differences reflecting variations in vegetation density and ecosystem structure. These findings highlight the complexity of soil carbon dynamics in temperate forests and the critical influence of environmental factors and plant-soil processes. The study provides essential insights for improving carbon cycling models and informs climate-resilient forest management strategies. Future research should prioritize long-term monitoring and experimental manipulations to better predict soil respiration under changing climatic conditions.
Bearing-shaft systems are essential components in various automated manufacturing processes, primarily designed for the efficient rotation of a main shaft by a motor. Accurate fault detection is critical for operating manufacturing processes, yet challenges remain in sensor selection and optimization regarding types, locations, and positioning. Sound signals present a viable solution for fault detection, as microphones can capture mechanical sounds from remote locations and have been traditionally employed for monitoring machine health. However, recordings in real industrial environments always contain non-negligible ambient noise, which hampers effective fault detection. Utilizing a high-performance microphone for noise cancellation can be cost-prohibitive and impractical in actual manufacturing sites, therefore to address these challenges, we proposed a convolution neural network-based methodology for fault detection that analyzes the mechanical sounds generated from the bearing-shaft system in the form of Log-mel spectrograms. To mitigate the impact of environmental noise in recordings made with commercial microphones, we also developed a denoising autoencoder that operates without requiring any expert knowledge of the system. The proposed DAE-CNN model demonstrates high performance in fault detection regardless of whether environmental noise is included(98.1%) or not(100%). It indicates that the proposed methodology effectively preserves significant signal features while overcoming the negative influence of ambient noise present in the collected datasets in both fault detection and fault type classification.
현재 기후변화 문제 해결을 위한 국제적 목표 및 국내 에너지 정책에 부합하는 LNG 발전의 효율성을 극대화하는 방안이 요구 되고 있다. 2050년 탄소중립 목표 달성을 위해 각국은 2030년까지 온실가스 감축 목표를 설정하였고, 국내에서도 석탄 발전 시설을 단계 적으로 폐쇄하고 LNG 발전 시설을 확대하려는 노력이 진행되고 있다. 이 연구에서는 LNG의 재기화 과정에서 발생하는 냉열을 회수하여 Carbon Capture and Storage, Ammonia-water Rankine Cycle / Kalina Cycle, Data Center Cooling, Direct Expansion 공정에 활용할 수 있는 시스템을 제안하였다. 연구 결과 제안된 시스템의 3E 분석 결과 Energy 효율 51.52%, Exergy 효율 42.74%, 환경적 측면에서 2,145.8 gCO2 / kgLNG의 탄 소 배출량을 보여 가장 우수한 성능을 확인하였다. 이를통해 본 연구에서 새롭게 제시한 시스템은 Energy, Exergy, 환경성 측면에서 강점을 가지며, 향후 기후변화 대응에 크게 기여할 것으로 판단된다.
This study investigated the behavior and environmental impact of expanded polystyrene (EPS) in a simulated marine environment, focusing on the effects of UV exposure. Through a series of controlled experiments, it was found that UV-induced weathering increased the formation of smaller EPS degradation products, leading to higher concentrations of dissolved organic carbon (DOC) in the seawater. Additionally, it was suggested that the assembly behavior of dissolved organic matter (DOM) contributed to the reduction of DOC levels over time. The EPS layer exhibited slightly higher DOC concentrations compared to the seawater, likely due to hydrophobic interactions that retained degradation products near the EPS. Analysis of the soil layer revealed that EPS particles and degradation products settled or adsorbed more extensively under UV conditions, indicating a greater risk of sediment contamination. Soil layer elution experiments further confirmed that EPS particles and their degradation products could migrate through soil pores, posing a potential contamination risk to other environments. UV exposure resulted in a twentyfold increase in DOC release from EPS compared to dark conditions. These findings highlight the persistent pollution potential of EPS in marine environments, especially under UV exposure, and emphasize the need for effective EPS waste management and further research into its environmental impacts.
This study aimed to assess the global and domestic efforts regarding the reduction of environmental-impact-factor emissions in the production and construction processes of concrete pavements. By utilizing internationally commercialized programs, this study sought to calculate the environmental impact factors generated by specific domestic concrete-pavement projects and identify areas for improvement. This study evaluated the global and domestic efforts of environmental impact reduction by focusing on the production and construction of concrete pavements. This study calculated the environmental impact factors for five cases using internationally commercialized software. The analysis revealed that, during the production and construction of concrete pavements, Portland cement production is a dominant cause of global warming, smog, acidification, and non-carcinogenic factors, whereas aggregate production is a dominant cause of ozone depletion, eutrophication, carcinogenicity, respiratory issues, environmental toxicity, and fossil-fuel depletion. This study analyzed the environmental impact factors of material mix and process during concrete pavement production and construction using foreign life-cycle inventory (LCI) databases. The environmental impact of each input material was identified. In the future, if an LCI and life-cycle impact assessment (LCIA) database for domestic road pavement materials is established and analyzed based on the conditions presented in this study, it is expected to lay the foundation for the development of environmentally friendly materials.
본 연구는 MaxEnt(Maximum Entropy Moedl) 모형을 이용하여 서울 도심 지역에서 너구리(Nyctereutes procyonoides) 출현 지역을 예측하고, 너구리 출몰에 영향을 미치는 환경 요인을 분석하였다. 분석은 2018년부터 2022년까지 수집된 서울시 야생동물센터의 구조 기록을 사용하였다. 토지 피복, 도로 면적, 경사도, 먹이원까지의 거리, 인구 밀도, NDVI(Normalized Difference Vegetation Index), 수역까지의 거리, 초지 면적을 환경 변수로 채택하여 가장 예측력이 높은 모델을 도출하였다. 분석 결과, 너구리 출몰 가능성이 높은 지역은 초지와 나지였고, 도로 밀도가 낮은 지역(<20%)에서 출몰할 가능성이 더 높았다. 또한 너구리는 경사가 완만하고(1.7˚), 먹이원에 가까우며(26.78m), 인구 밀도가 낮은(21.70명 /ha) 지역에서 발생할 가능성이 더 높았다. 다른 요인으로는 낮은 식생 밀도(NDVI 0.17), 하천과의 근접성(32.26m), 넓은 초지 지역(31.14%)에서 너구리가 출몰할 가능성이 높은 것으로 예측되었다. 서울 전역 중 약 65.42㎢(10.96%)가 잠재적인 너구리 발생 지역으로 확인되었으며, 주요 지역은 하천 주변, 산림 경계부, 도시공원 및 인근 초지와 농경지 주변이었다. 이 중 28개 지역(송파구 6개, 강서구 5개, 강남구 4개, 강동구 3개, 서초구 3개, 광진구, 노원구, 동대문구, 동작구, 마포구, 은평구, 중랑구 각각 1개 지역)이 너구리 발생 확률이 가장 높은 곳으로 확인되었다. 본 연구의 결과는 시민과 너구리의 공존 방안을 마련하는 데 중요한 기초 자료를 제공하며, 이를 통한 도시생태 전략 수립의 근거로 활용할 수 있을 것이다.
This study was conducted to prepare a plan for the controlling indoor microclimate environment using natural ventilation for the single-span plastic greenhouses, which account for about 83.8% of the total area of horticultural greenhouses in South Korea. The changes of indoor air temperature and relative humidity according to the side opening height were experimentally compared and analyzed in the experimental greenhouse. As the side opening height was changed to 30, 70, and 110cm, the indoor and outdoor temperature differences were found to be 14.0, 10.1, and 7.7℃, respectively. The indoor and outdoor relative humidity differences were found to be -15.7, -12.5, and -11.1%, respectively. These results were verified for statistical significance by ANOVA. When the variable breadth of the outdoor temperature was 6.9℃, the indoor temperature breadths were 14.5, 12.3, and 9.0℃, and when the outdoor relative humidity breadth was 24%, the indoor relative humidity breadths were 31.2, 28.0, and 23.8%, respectively. It was analyzed that as the side opening height is increased, the indoor temperature and relative humidity become similar to the outdoor environment. This is because the air is mixed by active indoor-outdoor air movement of greenhouses with natural ventilation. The results indicated that the proper opening and closing of side openings is necessary for the stable indoor microclimate environment control of plastic greenhouses.
퍼스널 모빌리티는 친환경 1인용 교통수단으로, 공유 서비스 도입 이후 이용자가 급격히 증가하였다. 연관 정책이 미비한 상태에서 이용자가 급증하였고, 이에 따라 서울시를 중심으로 퍼스널 모빌리티 사고가 증가하고 있으나 관련 연구가 부족한 실정이 다. 본 연구는 서울시를 중심으로 퍼스널 모빌리티 사고에 영향을 미치는 도시환경 요인을 파악하였다. 사고의 공간자기상관을 제거하기 위해 음이항 회귀모형 및 음이항 아이겐벡터 필터링 모형을 적용하였고, 각 모형을 비교한 후 최적 모형인 음이항 아이겐벡 터 필터링 모형의 결과를 바탕으로 사고 결과를 해석하였다. 본 연구는 인구, 교통, 사회 지표를 이용해 퍼스널 모빌리티 사고가 많이 일어나는 서울시 행정동의 특징을 확인하고 분석했다는 점에서 의의를 갖는다.
PURPOSES : This study aimed to improve the effect of increasing the number of urban railway users when public transportation accessibility is improved by using village buses. METHODS : Using the case of Daejeon City, this study utilized the greenhouse gas reduction benefit among the benefits of the investment evaluation guidelines of the Ministry of Land, Infrastructure and Transport to demonstrate the effect of introducing village buses, a flexible means of transportation, to transportation-disadvantaged areas and improving accessibility, thereby inducing a change to urban railways. and were quantitatively analyzed. RESULTS : The number of users expected to switch to urban rail was 9,964 in 2020 and 9,220 in 2025. Thus, the greenhouse gas reduction effect is predicted to decrease annually by 34,554 t (2020) and 31,973 t (2025). CONCLUSIONS : Among the demand management techniques, reducing the use rate of passenger cars is one of the most important. For this policy, it is most effective to provide an alternative means of transportation.
Currently, Japan is undertaking a nationwide project to measure and map radioactive contamination around Fukushima, as part of the efforts to restore normalcy following the nuclear accident. The Japan Atomic Energy Agency (JAEA) manages the Fukushima Environmental Safety Center, located approximately 20 km north of the Fukushima Daiichi nuclear power plant in Minamisōma City, Fukushima Prefecture. In collaboration with the JAEA, this study involved conducting comparison experiments and analyses with radiation detectors in high radiation environments, a challenging task in Korean environments. Environmental radiation surveys were conducted using three types of detectors: CZT, NaI(Tl), and LaBr3(Ce), across two contaminated areas. Dose rate values were converted using dose rate conversion factors for each detector type, and dose rate maps were subsequently created and compared. The detectors yielded similar results, demonstrating their feasibility and reliability in high radiation environments. The findings of this study are expected to be a crucial reference for enhancing the verification and supplementation of procedures and methods in future radiation measurements and mobile surveys in high-radiation environments, using these three types of radiation instruments.
항만 내 선박과 부두의 사고를 예방하기 위하여 통항 및 접안 안전성 평가를 통하여 안전한 부두가 건설되어 관리하고 있으나, 선 박의 접안 및 계류 과정에서 선박이 부두에 충돌하거나 로프로 인한 인명사고의 발생 등 예측할 수 없는 사고들이 종종 발생한다. 자동계류장 치는 선박의 신속하고 안전한 계류를 위한 자동화된 시스템으로 로봇 매니퓰레이터와 흡착 패드로 구성된 탈/부착 메커니즘을 가지고 있다. 본 논문은 자동계류장치의 흡착 패드의 위치 및 속도제어에 필요한 선체와의 변위 및 속도 측정 시스템을 다룬다. 자동계류장치에 적합한 측 정 시스템을 설계하기 위하여, 본 논문은 우선 센서의 성능 및 실외 환경적 특성 분석을 수행한다. 다음으로 이러한 분석 결과를 토대로 실외 부두환경에서 설치되는 자동계류장치에 적합한 변위 및 속도 측정시스템의 구성 및 설계 방법에 대해 기술한다. 또한 센서의 측정상태 감지 및 속도 추정을 위한 알고리즘을 제시한다. 제안된 방법은 다양한 속도 구간에서의 변위 및 속도 측정 실험을 통해 그 유용성을 검증한다.
eDNA (environmental DNA)란 특정 환경에 서식하는 생물로부터 유래한 DNA를 의미한다. 환경 시료로부터 추출한 eDNA를 활용하면 해당 환경에 서식하는 생물들의 효율적이고 정확한 모 니터링을 수행할 수 있다. 해수 시료로부터 얻은 eDNA를 기반으로 해양생물 다양성 연구를 수행할 수 있다. 해수 시료를 채집하고 이로부터 eDNA를 추출한 뒤, metagenome 분석을 통 해 서식하는 해양생물의 종 동정과 다양성 분석이 가능하다. 본 리뷰에서는 이처럼 해수의 eDNA를 활용하여 해양 지역의 생물 다양성 연구를 수행하는 전체적인 과정을 제시하고 있다. 아직 국내에는 해양생물 다양성 연구를 위해 eDNA를 적용하는 방법이 보편화 되어있지 않으 며, 본 리뷰를 기반으로 이와 같은 eDNA 연구 방법을 정립하는데 도움을 줄 수 있을 것이다.
Recently, a closed-type plant factory has been receiving attention as a advanced agricultural method. It has diverse advantages such as climate-independence, high productivity and stable year-round production. However, high energy cost caused by environmental control system is considered as a challenges of a closed-type plant factory. In order to reduce the energy cost, investigation about energy load which is directly connected to energy consumption needs to be conducted. In this study, energy load changes of a plant factory have been analytically analyzed according to the environmental changes. The target plant factory was a lettuce growing container farm. Firstly, the impact of photoperiod, set temperature and relative humidity change were examined. Under the climate condition of Daejeon in South Korea, increase of photoperiod and set temperature rose a yearly energy demand of a container farm. However, increase of set relative humidity decreased a yearly energy demand. Secondly, the climate environment effect was compared by investigating the energy demand under 9 different climate conditions. As a result, the difference between maximum and minimum value of the yearly energy demand showed 21.7%. Lastly, sensitivity analysis of each parameter (photoperiod, set temperature and relative humidity) has been suggested under 3 different climate conditions. The ratio of heating and cooling demand was varied depending on the climate, so the effect of each parameter became different.
산양삼은 산림청 특별관리 임산물로 지정되어 관리되고 있지만 체계적인 연구 나 표준 재배지침이 현장의 재배 현실과는 상이한 부분이 많은 실정이다. 이에 본 연구에서는 평창지역의 산양삼 재배지 환경조건에 따른 진세노사이드 함량이 어 떠한가를 알아보기 위하여 산양삼 시료를 각각 10본씩 채취하여 실험을 통해 확 인하였다. 산양삼 입지환경은 경사, 사면 방향, 해발고, 나무 종류, 흉고 직경과 수 고 등 모두 6가지를 조사하여 국립산림과학원의 분류기준을 참고하여 침엽과 활 엽으로 구분하였다. 산양삼 재배지의 토양산도를 포함한 9가지 토양이화학성 분석 에서는 전체적으로 침엽지역보다 활엽지역에서 높은 함량을 보였다. 통계분석 결 과에서는 A, B, C, 재배지에서 침엽과 활엽지역 간 통계적 유의성이 있는 것으로 나타났으며, D 재배지는 침엽과 활엽지역의 유의차가 거의 없는 것으로 나타났다. 진세노사이드 함유량 분석 결과에서는 Re, Rb1, Rg1의 순서로 높은 함량을 나타 내고 있어서 평창 산양삼의 주성분을 확인할 수 있었다. 연구 결과로 산양삼은 산 삼이 잘 생육할 수 있는 환경과 비슷한 곳을 재배지로 선정하여야 고품질의 제품 을 생산할 수 있다고 예상할 수 있다. 향후 본 연구 결과가 임업인 소득증대에 도 움을 줄 수 있는 자료로도 활용될 수 있기를 기대한다.
Environmental noise occurring on ships has various negative impacts on sailors’ health conditions such as hearing loss, sleep disturbance, psychological stress, etc., so regulations on them are required, but the ship noise regulations are usually applied to only large merchant ships. Although regulations on fishing boats with strong fishing and work intensity are determined to be necessary, there has been little relevant research. This study, therefore, attempted to measure the environmental noise of coastal composite fishing vessels less than two tones and provide the results of basic research on the noise regulations for fishing vessels. It measured them by setting the measurement zones as after side, midship and fore side, and based on the criterion of IMO MSC 337(91). The findings showed that the noise of them often exceeded 75dB(A), the criterion of the open deck noise in the zones in which the load of main engines was increased. In particular, the noise of the stern was as high as 92.2dB(A) during the full ahead. Hence, hearing loss may be caused by such a noise, so a variety of regulations on it are determined to be necessary.
The types and distribution ratio of odor removal systems installed in publicly owned environmental facilities such as sewage treatment, wastewater treatment, manure treatment, livestock manure treatment, and food waste treatment were investigated. Since the intensity of the odor and the composition of the odor substances are different depending on the type of each public treatment facility, different odor removal efficiencies were derived depending on the applied odor removal technology. In addition, the removal efficiency of complex odors and individual odor substances of odor removal systems such as those applying biofilters, scrubbers, and adsorption towers were also compared and evaluated. Although it depends on each odor removal technology and application facility, about 50% of various odor removal systems presented an odor removal performance of less than 30%. The odor removal systems with an odor removal efficiency of 70% or more were evaluated to be less than 30% of the total number. Therefore, we suggest that odor removal efficiencies should be improved through continuous monitoring, diagnosis, reinforcement of maintenance, and improvement of systems.
Recently, the construction of tall buildings utilized by high strength-concrete in the whole world is tending to be on the rise. The application of high-rise structural system in buildings results in the excellent cut-down effect in construction materials due to section reduction. Therefore, in order to investigate the CO2 and resource reduction effect for the high-rise structural system, comparisons of GWP and ADP in embodied energy of structural materlais between 4 type of high-rise structural system have been performed. As a result, GWP emission increased in the order of steel structure outrigger system, RC shear wall system, and RC outrigger system. On the other hand, ADP emissions increased in the order of RC shear wall system, RC outrigger system, and steel structure outrigger system.