강으로부터 해양으로 유입되는 퇴적물은 유역분지의 지질, 지리, 지형, 기후 등의 영향을 반영하며, 육상 유역분 지에서 퇴적물 생성 과정에서 수반되는 화학적 풍화는 대기 중 이산화탄소 농도를 조절하는 데에 중요한 역할을 하는 것으로 알려져 있다. 본 연구에서는 한반도 남해안 낙동강 하구 인근 해저 표층 퇴적물의 지화학 조성을 이용하여 화 학적 풍화의 강도와 퇴적물의 기원지에 분포하는 암석의 조성을 추정하였다. 연구 시료의 화학적 풍화 강도는 중간에 낮은 정도(평균 Chemical Index of Alteration=68)이며 A-CN-K 도표에서 추정한 풍화의 추세는 퇴적물의 기원지 성분 이 평균적인 상부 대륙지각과 매우 유사한 것으로 보인다. 이는 낙동강 유역분지에 분포하는 중생대 화강암류와 경상누 층군 퇴적암이 혼합된 성분을 반영하는 것으로 판단되기 때문에 연구 대상인 퇴적물이 낙동강 하구로부터 유입되는 퇴 적물의 성분을 대표하는 것으로 해석한다. 표층 퇴적물의 희토류원소는 분화된 경희토류-중희토류의 비와 음의 Eu 이상 을 나타내어 상부 대륙지각과 매우 유사하다. 본 연구의 결과를 전 세계 강 하구 퇴적물 자료 및 국내의 큰 강 자료와 비교하였으며, 이를 통하여 지질 및 지형의 잠재적인 영향을 고려할 수 있다.

This study conducted field surveys targeting benthic macroinvertebrates and fish in Andong Dam and Yeongsan River, with the specific aim of analyzing bluegill stomach contents. Bluegills in Andong Dam ranged from 40-220 mm, with 93.0% between 80-220 mm, while those in Yeongsan River ranged from 50-210 mm, with 71.4% between 120-210 mm. The highest feeding rates in both sites were for Chironomidae spp., with findings of 72.6% in Andong Dam and 80.4% in Yeongsan River. In Andong Dam, H. nipponensis and Baetidae sp. were also significant at 17.5% and 6.5%, respectively, while in Yeongsan River, Baetidae sp. (7.5%) and Hymenoptera sp. were the next most common at 3.8%. The EI index showed that bluegills generally avoided H. nipponensis and S. tsuchigae (-0.373 and -0.975) whereas they preferred Chironomidae spp. (0.759, 0.892) and Baetidae sp. (0.723). The parameter b values of the total length-weight relationship of bluegill were calculated as 3.452 in Andong Dam and 3.449 in the Yeongsan River, respectively. The slope values of the condition factor were 0.0067 in Andong Dam and 0.0065 in the Yeongsan River. Both values were positive, indicating that the nutritional status of bluegill was good. Aquatic insects constituted the primary food source, particularly in Yeongsan River. Feeding patterns did not significantly differ by habitat orientation groups, but Yeongsan River bluegills consumed more diverse food sources. In Andong Dam, larger bluegills likely consume food sources with larger biomass, while Yeongsan River’s diverse and abundant food sources support opportunistic feeding tailored to the water ecological environment.

본 연구는 예술가가 작품을 구상하는 과정에서 그 아이디어를 최초로 구현한 통합적 노 트인 플럭서스의 총보를 중심으로, 예술가의 통합적 노트가 융합적 창작을 기획하는 예술가 의 파라큐레토리얼의 실천으로써 가지는 시의성을 제시하고자 한다. 이를 위해, 리하르트 바 그너의 ‘총체예술’부터 빈 분리파가 제시하는 ‘예술가사회’ 그리고 라즐로 모홀리 나기가 바 우하우스 극과 ‘총체극’에서 제안하는 동등한 협업관계까지 융합적 창작에 대한 태도와 방식 이 어떻게 확장되어왔는지 먼저 살펴본다. 이러한 협업에 대한 관계의 성향, 태도 등은 이후 1950-60년대 현대음악 작곡과 전위적 퍼포먼스에서 다양한 장르의 예술가들이 함께 활동 하는 과정을 중심으로 재조명할 수 있다. 특히, 플럭서스가 제시하는 느슨한 예술가 커뮤니 티와 인터미디어의 개념을 총체예술의 계보 안에서 고찰해본다. 그리고 이 개념을 바탕으로 플럭서스 예술가들의 구체적인 총보와 퍼포먼스 사례들에서 예술가들이 서로가 서로의 기획 에 어떻게 퍼포머의 역할을 수행하여 협업했는지 그 과정을 추적한다. 당시 작곡이나 각본, 드로잉과 같은 형식으로 작성된 예술가의 통합적 노트가 작품화 되는 과정은 여러 예술가들 의 협업을 필요로 했다. 이 연구는 오늘날 다원 예술에서 예술가들이 서로의 작품에서 다양 한 역할을 수행하는 과정 중, 고려해야할 협업의 태도에 대한 지침이 될 것을 기대한다.

This study focuses on analyzing the energy-saving effects of the recirculation aquaculture system using seawater source heat pumps and solar power generation. Based on the thermal load analysis conducted using the transient system simulation tool, the annual energy consumption of the recirculation aquaculture system was analyzed and the energy-saving effects of utilizing the photovoltaic system was evaluated. When analyzing the heat load, the sea areas where the fish farms are located, the type of breeding tank, and the circulation rate of breeding water were taken into consideration. In addition, a method for determining the appropriate capacity for each operation time was examined when applying the energy storage system instead of the existing diesel generator as an emergency power, which is required to maintain the water temperature of breeding water during power outage. The results suggest that, among the four seas considered, Jeju should be estimated to achieve the highest energy-saving performance using the solar power generation, with approximately 45% energy savings.

There are growing concerns that the recently implemented Earthquake Early Warning service is overestimating the rapidly provided earthquake magnitudes (M). As a result, the predicted damages unnecessarily activate earthquake protection systems for critical facilities and lifeline infrastructures that are far away. This study is conducted to improve the estimation accuracy of M by incorporating the observed S-wave seismograms in the near source region after removing the site effects of the seismograms in real time by filtering in the time domain. The ensemble of horizontal S-wave spectra from at least five seismograms without site effects is calculated and normalized to a hypocentric target distance (21.54 km) by using the distance attenuation model of Q(f)=348f0.52 and a cross-over distance of 50 km. The natural logarithmic mean of the S-wave ensemble spectra is then fitted to Brune’s source spectrum to obtain the best estimates for M and stress drop (SD) with the fitting weight of 1/standard deviation. The proposed methodology was tested on the 18 recent inland earthquakes in South Korea, and the condition of at least five records for the near-source region is sufficiently fulfilled at an epicentral distance of 30 km. The natural logarithmic standard deviation of the observed S-wave spectra of the ensemble was calculated to be 0.53 using records near the source for 1~10 Hz, compared to 0.42 using whole records. The result shows that the root-mean-square error of M and ln(SD) is approximately 0.17 and 0.6, respectively. This accuracy can provide a confidence interval of 0.4~2.3 of Peak Ground Acceleration values in the distant range.

Despite enormous popularity of graphene oxide (GO) several open questions remain regarding the structure and properties of this material. One of those questions is the role of a graphite precursor on the properties of GO product. In this study, we investigate the oxidation process and the structure of GO products, made from the four different graphite precursors: synthetic graphite, two natural flaky graphites, and expanded graphite. The highest rate of the oxidation reaction was registered for the small particle size synthetic graphite. Thermal expansion of natural flaky graphite did not significantly affect the rate of the reaction. The nature of the graphite precursor does not notably affect the chemical composition of the synthesized GO products. However, it affects stability of respective aqueous dispersions. The solutions of the three GO samples, prepared from the natural graphite sources demonstrate excellent stability due to complete exfoliation of GO to single-atomic-layer sheets. GO from synthetic graphite forms unstable dispersions due to the presence of numerous multi-layered particles. This, in turn, is explained by the presence of not fully graphitized, amorphous inclusions in synthetic graphite. Our observations suggest that synthetic graphite should not be used as GO precursor when the ability to completely exfoliate and the stability of dispersions are critical for intended applications.

Over the last decade, there has been growing interest in the plastic degradation capabilities of insect because herbivorous insects may be a valuable resource for microorganisms that can break down synthetic plastics. Insects that can digest plastics using their gut microbiota are gaining interest for use in bioremediation, although their environmental benefits remain unknown. However, most plastics biodegraded by insect gut microbes are polyethylene, polystyrene with little knowledge available on the gut microbiome of insects capable of degrading other synthetic plastics. Therefore, there is an urgent need to secure microbial resources based on insect-microbiome interactions and promote end-of-life solutions for synthetic plastics.

This study deals with the application of an artificial neural network (ANN) model to predict power consumption for utilizing seawater source heat pumps of recirculating aquaculture system. An integrated dynamic simulation model was constructed using the TRNSYS program to obtain input and output data for the ANN model to predict the power consumption of the recirculating aquaculture system with a heat pump system. Data obtained from the TRNSYS program were analyzed using linear regression, and converted into optimal data necessary for the ANN model through normalization. To optimize the ANN-based power consumption prediction model, the hyper parameters of ANN were determined using the Bayesian optimization. ANN simulation results showed that ANN models with optimized hyper parameters exhibited acceptably high predictive accuracy conforming to ASHRAE standards.

Captive breeding and reintroduction are crucial strategies for conserving endangered species populations. However, fish raised in predator-free environments, show a lack of recognition of predationrelated stimuli such as chemical and visual signals. It is critical to recognize chemical signals from injured conspecifics, also known as alarm signals, and the order or shape of predators to indicate the spread of predation risk in the habitat. We conducted a laboratory experiment to determine and adjust the optimal exposure period to induce appropriate anti-predator behavior response to different types of stimuli (Chemical, Visual and Chemical+Visual) for the endangered species Microphysogobio rapidus. Our results demonstrate that predator avoidance behavior varies depending on the types of stimuli and the duration of predation risk exposure. First, the results showed captive-breed M. rapidus show lack of response against conspecific alarm signal (Chemical cue) before the predation risk exposure period and tend to increase response over predation risk exposure time. Second, response to predator (visual cue) tend to peak at 48 hours cumulative exposure, but show dramatic decrease after 72 hours cumulative exposure. Finally, response to the mixed cue (Chemical+visual) tend to peak prior to the predation risk exposure period and show reduced response during subsequent exposure periods. This experiment confirms the lack of responsiveness to conspecific alarm signals in captive-bred M. rapidus and the need for an optimal nature behavior enhancement program prior to release of endangered species. Furthermore, responsiveness to predator visual signal peak at 48 hours cumulative exposure, suggest an optimal predation risk exposure period of up to 48 hours. Key words: predator cognition, captive breeding, chemical signal, visual signal, endangered

After the major radioactivation structures (RPV, Core, SG, etc.) due to neutron irradiation from the nuclear fuel in the reactor are permanently shut down, numerous nuclides that emit alpha-rays, beta-rays, gamma-rays, etc. exist within the radioactive structures. In this study, nuclides were selected to evaluate the source term for worker exposure management (external exposure) at the time of decommissioning. The selection of nuclides was derived by sequentially considering the four steps. In the first stage, the classification of isotopes of major nuclides generated from the radiation of fission products, neutron-radiated products, coolant-induced corrosion products, and other impurities was considered as a step to select evaluation nuclides in major primary system structures. As a second step, in order to select the major radionuclides to be considered at the time of decommissioning, it is necessary to select the nuclides considering their half-life. Considering this, nuclides that were less than 5 years after permanent suspension were excluded. As a third step, since the purpose of reducing worker exposure during decommissioning is significant, nuclides that emit gamma rays when decaying were selected. As a final step, it is a material made by radiation from the fuel rod of the reactor and is often a fission product found in the event of a Severe accident at a nuclear power plant, and is excluded from the nuclide for evaluation at the time of decommissioning is excluded. The final selected Co-60 is a nuclide that emits high-energy gamma rays and was classified as a major nuclide that affects the reduction of radiation exposure to decommissioning workers. In the future, based on the nuclide selection results derived from this study, we plan to study the evaluation of worker radiation exposure from crud to decommissioning workers by deriving evaluation results of crud and radioactive source terms within the reactor core.

Spent nuclear fuel continues to be generated domestically and abroad, and various studies are actively being conducted for interim dry storage and disposal of spent nuclear fuel. The characteristics vary depending on the type of spent nuclear fuel and the initial specifications, and based on these characteristics, it is essential to estimate the burnup and enrichment of spent nuclear fuel as a nondestructive assay. In particular, it is important to estimate the characteristics of spent nuclear fuel with non-destructive tests because destructive tests cannot be performed on all encapsulated spent nuclear fuel in case of intrusion traces in safeguards. Data is made by measuring spent nuclear fuel directly to evaluate burnup of spent nuclear fuel, but computer simulation research is also important to understand its characteristics because past burnup history is not accurately written, and destructive testing is difficult. In Sweden, the dependency of the burnup history in source strength and mass of light-water reactor-type spent nuclear fuel was evaluated, and this part was also applied to MAGNOX in consideration of the possibility of being used to verify DPRK’s denuclearization. SCALE 6.2 TRITON modeling was performed based on public information on DPRK’s 5 MWe Yongbyon reactor, and the source strength of Nb-95, Zr-95, Ru-106, Cs-134, Cs-137, Ce-141, Ce- 144, Eu-154 nuclides were evaluated. Since the burnup of MAGNOX is lower than that of lightwater reactors, major nuclides in decay heat were not considered. The cooling period was evaluated based on 0, 5, 10, and 20 years. In case the discharge timing was different, the total period of discharge and reloading was the same, and the end-cycle burnup was the same, calculations showed that the source strength emitted from major nuclides was evaluated within 2-3% except for Ru-106 and Ce-144 nuclides. Even the burnup step of nuclear fuel is the same, and the reloaded length after discharge is different, i.e., the cooling period between is different at 5, 10, and 20, the source strength of Nb-95, Zr-95, Ce-144, and Cs-137 was evaluated as an error of 1%. Except for Ru-106 and Ce-144, nuclides are highly dependent on burnup. Compared to the case of light-water reactors, the possibility of a decrease in error needs to be considered later because the specific power is low. As a result, radionuclides in released fuel depend on the effects of burnup, discharged and reloaded period, and a cooling period after release, and research is needed to correct the cooling period within the future burnup history. In addition, in this study, it is necessary to select a scenario -based burnup because the standard burnup due to the statistical treatment of discharged fuels was not considered as conducted in previous studies.

Spent fuels (SFs) are stored in a storage pool after discharge from nuclear power plants. They can be transferred to for the further processes such as dry storage sites, processing plants, or disposal sites. One of important measures of SF is the burnup. Since the radioactivity of SF is strongly dependent on its burnup, the burnup of SF should be well estimated for the safe management, storage, and final disposal. Published papers about the methodology for the burnup estimation from the known activities of important radioactive sources are somewhat rare. In this study, we analyzed the dependency of the burnup on the important radiation source activities using ORIGEN-ARP, and suggested simple correlations that relate the burnup and the important source activities directly. A burnup estimation equation is suggested for PWR fuels relating burnup with total neutron source intensity (TNSI), initial enrichment, and cooling time. And three burnup estimation equations for major gamma sources, 137Cs, 134Cs, and 154Eu are also suggested.

Currently, yellow phosphor of Y3Al5O12:Ce3+ (YAG:Ce) fluorescent material is applied to a 450~480nm blue LED light source to implement a white LED device and it has a simple structure, can obtain sufficient luminance, and is economical. However, in this method, in terms of spectrum analysis, it is difficult to mass-produce white LEDs having the same color coordinates due to color separation cause by the wide wavelength gap between blue and yellow band. There is a disadvantage that it is difficult to control optical properties such as color stability and color rendering. In addition, this method does not emit purple light in the range of 380 to 420nm, so it is white without purple color that can not implement the spectrum of the entire visible light spectrum as like sunlight. Because of this, it is difficult to implement a color rendering index(CRI) of 90 or higher, and natural light characteristics such as sunlight can not be expected. For this, need for a method of implementing sunlight with one LED by using a method of combining phosphors with one light source, rather than a method of combining red, blue, and yellow LEDs. Using this method, the characteristics of an artificial sunlight LED device with a spectrum similar to that of sunlight were demonstrated by implementing LED devices of various color temperatures with high color rendering by injecting phosphors into a 405nm deep blue LED light source. In order to find the spectrum closest to sunlight, different combinations of phosphors were repeatedly fabricated and tested. In addition, reliability and mass productivity were verified through temperature and humidity tests and ink penetration tests.

Corporate Social Responsibility (CSR) activities substantially impact a company’s reputation. As companies increasingly embrace social media to communicate CSR activities, they face the challenge of selecting the appropriate message source. In this context, this paper examines the role of message source in the relationship between CSR communication and corporate reputation.

The purpose of this research is to better understand what factors influence on households’ waste sorting behavior at source in Mongolia. To accomplish the goal, this study conducted online survey with self-report questionnaire method and the 353 participants’ data were collected through Facebook groups and pages related to house owners’ associations and waste recycling related non-profit organizations. The results show that the underlying factors determining the intention of waste sorting at source are (1) motivational bases such as prior beliefs and social norms; (2) and an ability/knowledge about the waste sorting at source. Furthermore, the intention is crucial predictor of the real behavior of waste sorting at source, but the most important one is an opportunity to do so. The conclusions and the recommendations are provided.