The common snapping turtle (Chelydra serpentina), which is native to North America, started to be imported into South Korea as pets in the 1990s. The turtle was sold in supermarkets and pet shops nationwide at low prices such as 20 USD. These non-native turtles, with their large size and strong predatory nature, have been consistently discovered in the wild in South Korea beginning in 2014, and they were designated as an ecosystem-disturbing species (EDS) in October 2022. Until June 30, 2023, a collection system was implemented to reduce the abandonment problem of C. serpentina due to their designation as an EDS. In this study, we analyzed the impacts of the legal designation as an ecologically disturbing species and the collection system of C. serpentina on their abandonment and surrender. Our findings showed that designation as EDS did not affect the abandonment of C. serpentina. Meanwhile, the collection system led to cases of immediate surrender. Within 3 years of post-purchase, 41.8% of the turtles were surrendered, and 67.5% were surrendered when they reached 3 kg. Determining the impact of the legal designation as an EDS may be currently limited due to the difficulty of detecting C. serpentina in the wild. On the other hand, cases of surrender through the collection system are considered to be effective as they have been shown to reduce the abandonment of this newly designated ecosystem-disturbing species.

This study investigated the fish fauna of Jeonjucheon and Samcheon Streams, flowing through the city of Jeonju, through surveys conducted at 10 sampling sites using kick net and cast net. The fish fauna collected included 10 families and 36 species, with a total of 2,064 individuals. Samcheon had 8 families and 30 species with 1,074 individuals, Jeonjucheon had 8 families and 26 species with 986 individuals. The dominant species was Zacco platypus with 1,202 individuals, and a total of 153 individuals of the subdominant were Pseudogobio esocinus. In Jeonjucheon Stream, a total of 567 individuals of the dominant species were collected as Z. platypus and 99 individuals of the subdominant species were collected as Pungtungia herzi, and there was no significant change in the stream environment except for the confluence site. Further expanded research covering the entire Jeonjucheon and Samcheon Streams region, accompanied by regular monitoring, is essential to record and understand fluctuations in fish fauna.

빠르게 발전하는 이미지 인식 기술에도 불구하고 표 형식의 문서와 수기로 작성된 문서를 완벽하게 디지털화하기에는 아직 어려움이 따른다. 본 연구는 표 형식의 수기 문서인 선박 항해일지를 작성하는 데에 사용되는 규칙을 이용하여 보정 작업을 수행함으로 써 OCR 결과물의 정확도를 향상시키고자 한다. 이를 통해 OCR 프로그램을 통하여 추출된 항해일지 데이터의 정확성과 신뢰성을 높일 것 으로 기대된다. 본 연구는 목포해양대학교 실습선 새누리호의 2023년에 항해한 57일간의 항해일지 데이터를 대상으로 OCR 프로그램 인 식 후 발생한 오류를 보정하여 그 정확도를 개선하고자 하였다. 이 모델은 항해일지 기재 시 고려되는 몇 가지 규칙을 활용하여 오류를 식별한 후, 식별된 오류를 보정하는 방식으로 구성하였다. 모델을 활용하여 오류를 보정 후, 그 효과를 평가하고자 보정 전과 후의 데이터 를 항차별로 구분한 후, 같은 항차의 같은 변수끼리 비교하였다. 본 모델을 활용하여 실제 셀 오류율은 약 11.8% 중 약 10.6%의 오류를 식 별하였고, 123개의 오류 중 56개를 개선하였다. 본 연구는 항해일지 중 항해정보를 기입하는 Dist.Run부터 Stand Course까지의 정보만을 대 상으로 수행하였다는 한계점이 있으므로, 추후 항해정보 뿐만 아니라 기상정보 등 항해일지의 더 많은 정보를 보정하기 위한 연구를 진 행할 예정이다.

In this study, a core-shell powder and sintered specimens using a mechanically alloyed (MAed) Ti-Mo powder fabricated through high-energy ball-milling are prepared. Analysis of sintering, microstructure, and mechanical properties confirms the applicability of the powder as a sputtering target material. To optimize the MAed Ti-Mo powder milling process, phase and elemental analyses of the powders are performed according to milling time. The results reveal that 20 h of milling time is the most suitable for the manufacturing process. Subsequently, the MAed Ti-Mo powder and MoO3 powder are milled using a 3-D mixer and heat-treated for hydrogen reduction to manufacture the core-shell powder. The reduced core-shell powder is transformed to sintered specimens through molding and sintering at 1300 and 1400oC. The sintering properties are analyzed through X-ray diffraction and scanning electron microscopy for phase and porosity analyses. Moreover, the microstructure of the powder is investigated through optical microscopy and electron probe microstructure analysis. The Ti-Mo core-shell sintered specimen is found to possess high density, uniform microstructure, and excellent hardness properties. These results indicate that the Ti-Mo core-shell sintered specimen has excellent sintering properties and is suitable as a sputtering target material.

This study developed an IoT-based agricultural well control system and demonstrated it through a control system in the current state of domestic open-field smart farms where systematic management is insufficient due to the difficulty of collecting accurate data such as agricultural water intake and usage. As a result, it was possible to derive the optimal control system test results according to the watering conditions for each schedule by conducting automatic control focusing on periods when there is no precipitation. This means that irrigation can be carried out smoothly during the time when irrigation is needed to improve crop quality and secure farm income, and as a result, it is possible to systematically manage and operate among demonstration farms connected to irrigation, resulting in a shortage of agricultural water and a resolution of supply imbalances.

해양공간계획(Marine spatial planning)은 해양의 합리적인 이용과 지속 가능한 해양 공간 활용을 위한 중요한 요소이다. 특히 어업활동 보호구역은 지속 가능한 어업을 위한 핵심 용도구역으로, 해양공간계획 경계 내에서 약 45.6%를 차지한다. 그러나, 현재 어업활동보호구역의 지정 과 평가는 미래 수요와 잠재적 가치를 충분히 반영하지 못하고 있으며, 중장기 계획 수립을 위한 보다 합리적인 평가 방법과 예측 도구가 필요한 상황이다. 이러한 문제를 해결하기 위해, 본 연구는 어업활동보호구역 내 주요 어종인 고등어, 갈치, 멸치, 참조기를 대상으로 어종 분포 예측을 시도하고, 현재 용도구역과의 비교를 통해 예측 도구의 가능성을 평가하였다. 한편, IPCC 6차 기후변화 시나리오(SSP1-2.6 및 SSP5-8.5)를 적용한 종분포 모델(MaxEnt)을 사용하여 미래 기후변화에 따른 어종의 이동 및 분포 변화를 분석한 결과, 고등어, 갈치, 참조기의 분포 면적은 현재보다 약 28~86% 증가했으나, 멸치의 분포 면적은 약 6~11% 감소했다. 이 결과를 바탕으로 주요 4종의 종풍부도 지도를 작성하였으며, 해양공간계획 경 계 내에서 ‘높음’으로 평가된 종풍부도 해역과 어업활동보호구역이 중복되는 비율은 약 15%, SSP1-2.6 시나리오에서 21%, SSP5-8.5 시나리오에서 34%로 증가하였다. 연구 결과는 향후 용도구역 평가나 유보구역 변경 시 과학적 근거로 활용될 수 있으며, 어종의 현재 종분포와 기후변화에 따 른 분포 예측을 통해 현재 용도구역 평가의 한계를 보완하고, 지속 가능한 유용 해양 자원의 이용을 위한 계획 수립에 기여할 것으로 판단된다.

Piezoelectric technology, which converts mechanical energy into electrical energy, has recently attracted drawn considerable attention in the industry. Among the many kinds of piezoelectric materials, BaTiO3 nanotube arrays, which have outstanding uniformity and anisotropic orientation compared to nanowire-based arrays, can be fabricated using a simple synthesis process. In this study, we developed a flexible piezoelectric energy harvester (f-PEH) based on a composite film with PVDF-coated BaTiO3 nanotube arrays through sequential anodization and hydrothermal synthesis processes. The f-PEH fabricated using the piezoelectric composite film exhibited excellent piezoelectric performance and high flexibility compared to the previously reported BaTiO3 nanotube array-based energy harvester. These results demonstrate the possibility for widely application with high performance by our advanced f-PEH technique based on BaTiO3 nanotube arrays.

The present study estimated rumen fermentation characteristics and greenhouse gas emissions of different forages. Alfalfa, timothy, tall fescue, Italian ryegrass, and rice straw as the main forage sources for Hanwoo were used in the present study. Crude protein was highest in alfalfa but lowest in rice straw (p<0.05). Ether extract was higher in alfalfa and Italian ryegrass than in the other forages (p<0.05). Crude ash was highest in rice straw but lowest in tall fescue (p<0.05). Neutral detergent fiber was highest in tall fescue but lowest in alfalfa (p<0.05). Acid detergent fiber was highest in Italian ryegrass and rice straw but lowest in alfalfa (p<0.05). In vitro digestibilities of dry matter (DMD) and neutral detergent fiber (NDFD) were highest in timothy but lowest in rice straw (p<0.05). Rumen pH was highest (p<0.05) in alfalfa, while ammonia-N was higher (p<0.05) in alfalfa and Italian ryegrass than in the other forages. Total volatile fatty acid was highest (p<0.05) in timothy, while acetate and propionate were highest (p<0.05) in alfalfa and rice straw, respectively. Acetate to propionate ratio was higher (p<0.05) in alfalfa, timothy, and Italian ryegrass than in rice straw. Rice straw had lowest total gas (mL) (p<0.05) but highest its per DMD and NDFD. Rice straw had higher (p<0.05) CO2 (per DMD and NDFD) compared to alfalfa (per DMD and NDFD), timothy (per DMD and NDFD), tall fescue (per NDFD), and Italian ryegrass (per DMD). Again, rice straw had higher (p<0.05) CH4 (per DMD and NDFD) compared to timothy (per DMD and NDFD) and tall fescue (per NDFD). Therefore, this study indicates that timothy has a higher nutrient digestibility and volatile fatty acid in the rumen leading to a reduction of greenhouse gas emission.

The purpose of this study was to propose an operational concept for a ship in a fleet equipped with an interceptor missile system, a naval surface to air defense system, and to develop a simulation program that reflects it. The results of the defense activities of other ships in the fleet can be reflected by receiving information about the status of the enemy missiles. The allocation of defensive assets is based on the survival probability of the ship, not on the destruction of enemy attacks, which can be obtained as the product of the expected survival probability for each enemy missile. In addition, the concept of predicted survivability was introduced to assess the loss of future defense opportunities that would result from assigning a new command. A simulation program was also developed as a tool for realizing the proposed concept of operations, which generated cases.

우리나라 여러 해양환경 지역으로부터 확보한 370주의 해양세균, 균류, 미세조류로부터 기초생 리활성(항산화, 항염, 항균, 항암, 항바이러스)을 조사하여 채집지, 분리원, 종(種) 수준에서의 활성결과를 비교하였다. 해양세균의 경우, 일반적으로 유용성이 많이 알려진 Streptomyces 속 과 Bacillus 속에 속하는 균주들이 두드러진 강한 효능이 관찰되었고, 주로 해양퇴적물로부터 유용한 자원을 분리할 수 있었다. 해양균류와 미세조류의 경우에도 종 특이적으로 활성이 강 하게 나타나는 결과를 확인할 수 있었고, 효능 특이적으로 활성을 보이는 결과도 얻을 수 있었 다. 이러한 결과를 바탕으로 추후 특정질병에 선택적으로 효능을 보이는 화학물질 연구 또는 자원 기반 연구 수행 시 유용성을 전제로 한 자원 확보 전략 수립과 산업 활성화를 위한 전 략소재로 우선적 접근이 용이할 수 있는 연구결과라 생각된다. 또한, 이들 결과를 해양바이오 뱅크를 통한 분양소재로 활용함으로써 학계, 산업계에서 활용하여 해양바이오산업 활성화에 좀 더 빠른 접근을 도울 수 있다고 생각한다.

In Korea, from January 2023, the Act on Labeling and Advertising of Food was revised to reflect the use-by-date rather than the sell-by-date. Hence, the purpose of this study was to establish a system for calculating the safety factor and determining the recommended use-by-date for each food type, thereby providing a scientific basis for the recommended use-by-date labels. A safety factor calculation technique based on scientific principles was designed through literature review and simulation, and opinions were collected by conducting surveys and discussions including industry and academia, among others. The main considerations in this study were pH, Aw, sterilization, preservatives, packaging for storage improvement, storage temperature, and other external factors. A safety factor of 0.97 was exceptionally applied for frozen products and 1.0 for sterilized products. In addition, a between-sample error value of 0.08 was applied to factors related to product and experimental design. This study suggests that clearly providing a safe use-by-date will help reduce food waste and contribute to carbon neutrality.

As the demand for p-type semiconductors increases, much effort is being put into developing new p-type materials. This demand has led to the development of novel new p-type semiconductors that go beyond existing p-type semiconductors. Copper iodide (CuI) has recently received much attention due to its wide band gap, excellent optical and electrical properties, and low temperature synthesis. However, there are limits to its use as a semiconductor material for thin film transistor devices due to the uncontrolled generation of copper vacancies and excessive hole doping. In this work, p-type CuI semiconductors were fabricated using the chemical vapor deposition (CVD) process for thin-film transistor (TFT) applications. The vacuum process has advantages over conventional solution processes, including conformal coating, large area uniformity, easy thickness control and so on. CuI thin films were fabricated at various deposition temperatures from 150 to 250 °C The surface roughness root mean square (RMS) value, which is related to carrier transport, decreases with increasing deposition temperature. Hall effect measurements showed that all fabricated CuI films had p-type behavior and that the Hall mobility decreased with increasing deposition temperature. The CuI TFTs showed no clear on/off because of the high concentration of carriers. By adopting a Zn capping layer, carrier concentrations decreased, leading to clear on and off behavior. Finally, stability tests of the PBS and NBS showed a threshold voltage shift within ±1 V.

In the last five decades, there has been a consistent decline in the total catch of fisheries in the Korean jurisdiction since the peak in 1986. The decline in catch slowed and slightly rebounded in the 2000s, but changed back to a decline in the 2010s. As indicators that can identify changes in the marine ecosystem, trophic level (TL), biodiversity index (H'), and the ratio between pelagic fish and demersal fish (P/D) were analyzed by each local marine ecosystem. There were some different changes in each local marine ecosystem, but the mean TL and H' decreased and P/D increased in general in Korean waters. Demersal fish, which were dominant in the 1970s and 1980s, declined, and small pelagic fish and cephalopods have dominantly changed since the 1990s. However, these changes are not simple, and they are fluctuating in complex ways relating to each marine ecosystem and the timing. It is believed that changes in marine ecosystems in Korean waters are likely caused by a combination of fisheries and climate change. The ecosystem indicators reflected a change in the total catch, a sharp drop in catch of demersal fish, and increasing catch of pelagic fish since the mid-1980s.

This study explores strategies to address the variability of heat energy using renewable energy and heat grids to achieve carbon neutrality. Renewable energy source introduce fluctuations that can impact the stability of power systems, while heat grids provide a systematic infrastructure for efficient supply of heat energy and power generation. Jeju Island is chosen as a case study, focusing on balance control based on groundwater-based geothermal energy to optimize the distribution of heat energy. The results demonstrate that the 3rd control method is the most effective in maintaining the target temperature in greenhouses, and specific temperature settings and objectives are proposed for each control method based on crop requirements. These research findings contribute to achieving carbon neutrality and reducing power consumption.

This study was aimed to determine the changes in CO2 concentration according to the temperatures of daytime and nighttime in the CO2 supplemental greenhouse, and to compare calculated supplementary CO2 concentration during winter and spring cultivation seasons. CO2 concentrations in experimental greenhouses were analyzed by selecting representative days with different average temperatures due to differences in integrated solar radiation at the growth stage of leaf area index (LAI) 2.0 during the winter season of 2022 and 2023 years. The CO2 concentration was 459, 299, 275, and 239 μmol·mol-1, respectively at 1, 2, 3, and 4 p.m. after the CO2 supplementary time (10:00-13:00) under the higher temperature (HT, > 18°C daytime temp. avg. 31.7, 26.8, 23.8, and 22.4°C, respectively), while it was 500, 368, 366, 364 μmol·mol-1, respectively under the lower temperature (LT, < 18°C daytime temp. avg. 22.0, 18.9, 15.0, and 13.7°C, respectively), indicating the CO2 reduction was significantly higher in the HT than that of LT. During the nighttime, the concentration of CO2 gradually increased from 6 p.m. (346 μmol·mol-1) to 3 a.m. (454 μmol·mol-1) in the HT with a rate of 11 μmol·mol-1 per hour (240 tomatoes, leaf area 330m2), while the increase was very lesser under the LT. During the spring season, the CO2 concentration measured just before the start of CO2 fertilization (7:30 a.m.) in the CO2 enrichment greenhouse was 3-4 times higher in the HT (>15°C nighttime temperature avg.) than that of LT (< 15°C nighttime temperature avg.), and the calculated amount of CO2 fertilization on the day was also lower in HT. All the integrated results indicate that CO2 concentrations during the nighttime varies depending on the temperature, and the increased CO2 is a major source of CO2 for photosynthesis after sunrise, and it is necessary to develop a model formula for CO2 supplement considering the nighttime CO2 concentration.

식물구계학적 특정종은 식물상 정보를 이용한 지역환경을 평가하는 주요 수단이며, 종의 선정과 평가는 식물구계 정보에 의거해서 이루어진다. 본 연구는 이러한 식물구계에 대해 학술적 진의를 규명하고자 하였다. 식물구계 관련 핵심문헌 7편을 검토하였으며, 식물구계 적용 근거를 비교 검증하였다. 1919년의 Nakai 울릉도 식물상 조사보고서는 식물구계에 관련한 일반적인 지리구분(지방)을 처음으로 기재했다. Oh는 1977년에 한국의 유관속식물에 대한 식물지리구계도를 처음으로 제시하였 다. 1978년에는 Lee & Yim이 중부와 남부를 가르는 구계도를 제시했고, 그 밖에 많은 연구자들에 의해 식물구계 경계는 조정되고 개정되었다. 마침내 2018년에는 Lee & Yim (1978)에서 변형된 식물구계학적 특정종의 식물구계도가 채택되었다. 그런데 이러한 식물구계들은 연구자 간에 차이가 있었고, 구계 지표 식물의 불일치성도 확인되었다. 그럼에도 그런 상이성에 대한 근거는 찾을 수 없었다. 결론적으로 도식화된 모든 식물구계도는 선험적으로 그은 임의 선에 의존하고 있었다. 본 연구는 식물구계학적 특정종이 환경영향평가 및 국가 식물상 평가를 위한 과학적 수단으로서 그 실효성과 실체성을 확보하기 위해 다음의 두 가지 생태학적 전략을 제안했다 : 종분포 고유성(nativeness) 정보를 바탕으로 하는 식물상 및 식물구계의 성취와 서식처 기반(habitat-based) 식물상 장기모니터링 시스템의 구축.

본 연구는 해양산업시설에서 배출되는 위험·유해물질(Hazardous and Noxious Substances) 중 아연을 대상으로 국내 서식종을 기반 으로 한 독성시험을 수행하고, 그 결과를 활용하여 국내 실정에 맞는 아연의 해양 수질 준거치(Marine Water Quality Criteria)를 제안하였다. 시험생물은 국내 연근해에 분포하고 산업적으로 유용하며, 표준 시험방법이 존재하는 종을 우선으로 5개의 분류군(Algae, Rotifer, Crustacean, Mollusc, Fish)의 총 10종을 선정하여 독성시험을 수행하였으며, 급·만성비(Acute-Chronic Ratio) 산출을 위하여 무척추동물, 어류 분류군에 대한 만성독성시험을 수행하였다. 국내종 독성시험에서 산출된 독성값을 활용한 수질준거치는 US EPA의 CCC (Criterion Continuous Concentration) 산출 기준으로 9.56 ㎍/L, 호주/뉴질랜드의 산출 기준으로 15.50 ㎍/L 로 나타나 호주/뉴질랜드에서 권고하는 기준인 14.40 ㎍/L 와 유사하였다. US EPA 및 호주/뉴질랜드는 자국의 생태독성 데이터베이스(US EPA Ecotox Database, Australasian Ecotoxicology Database)를 보유하고, 신뢰도 높은 독성값들을 생성하여 수질 기준 및 산출 기준을 갱신하고 있다. 한편, 국내에서는 국내종 기반 급성 독 성값을 적용하고 있지만, 중요한 산출 지표인 급·만성비는 US EPA 또는 유럽의 결과값을 활용하여 해양 수질 준거치를 산출하고 있으며, 국내의 생태독성 자료 또한 제한적인 실정이다. 따라서, 국내 해양 서식종을 기반으로 한 지속적인 독성시험과 준거치 설정 체계를 확보하 여 국내 해양생물과 생태계를 보호할 수 있는 해양 수질 준거치 도출이 필요할 것으로 판단된다.