전 세계 이산화탄소 배출량이 지속적으로 증가하면서, 환경 개선 및 탄소 격리를 위한 다양한 연구들이 진행되고 있 다. 건설 산업에서도 탄소를 줄이기 위한 연구로 바이오차를 건설 자재에 사용하여, 탄소 격리를 위한 방법으로 진행되고 있다. 바이오차는 바이오매스를 열분해하여 생성한 숯으로, 높은 탄소 함량과 다공성 구조가 특징이며, 탄소 격리를 위한 물질로 떠오 르고 있다. 본 연구에서는 시멘트 사용량을 줄이고 바이오차를 혼입한 콘크리트를 건설 자재로써 가능성을 확인하고자 하였다. 이를 위해 시멘트의 일부를 바이오차로 치환하여 혼입한 콘크리트의 역학적 특성(슬럼프, 공기량, 압축강도)과 질량 기반 특성 (흡수율, 밀도, 공극률)을 평가하였다. 바이오차의 시멘트 치환율은 0%, 5%, 10%로 설정하였다. 바이오차의 수분 흡수 및 보유 력에 따라 바이오차의 시멘트 치환율이 증가할수록 슬럼프는 감소하였다. 바이오차의 다공성 구조를 SEM 실험으로 확인하였으 며, 이에 따라 콘크리트에서의 공극 형성으로 바이오차의 시멘트 치환율이 증가할수록 공기량과 흡수율이 증가하였다. 바이오차 의 시멘트 치환율 5%에서 압축강도와 비강도가 가장 높은 값으로 나타났으며, 탄소 격리를 위한 방법으로 건설 자재 활용의 가능성을 확인하였다.

Microalgae are efficient fatty acid producers owing to their high photosynthetic activities. They can act as sources of biofuel, feed, and various bioactive compounds. This study aimed to determine optimal culture conditions, including culture medium, temperature, and light intensity, to enhance the biomass and fatty acid content of the indigenous freshwater microalga, Tetradesmus obliquus. Evaluation using a high-throughput photobioreactor revealed that the optimal culture temperature and light intensity were 25°C and 300 μmol m-2 s-1, respectively. Additionally, we optimized components (N, P, and Mg) of the BG-11 medium to enhance the microalgal biomass. Modified BG-11 medium increased the T. obliquus biomass by 37% compared to the standard BG-11 medium. Subsequently, the culture medium was replaced with N- and P-depleted media to determine the abiotic stress factor that could increase the cellular fatty acid content. Notably, fatty acid content was significantly increased from 8.5% up to 14.6% on day 7 of culture in N-deficient (N-P+ and N-P-) media. Sequential optimization effectively increased the biomass by 83% and fatty acid content by >76% in T. obliquus. Our optimization method can be used to enhance the biomass and fatty acid contents of various other microalgae.

Reinforced concrete (RC) piloti buildings are vulnerable in the event of earthquake because the stiffness in the 1st story columns is weak to compare with the members in upper stories. In this study, seismic performances of RC piloti structures were evaluated considering with different types of floor plane layouts according to core eccentricity. With four types of floor plane layouts, five stories plioti structures were evaluated by two approaches, a nonlinear pushover analysis and a nonlinear time-history analysis. In order to improve seismic performances by satisfying the collapse prevention (CP) level, two ductile reinforcing methods by carbon fiber sheets and steel jackets were applied. Due to eccentricities in stiffness and mass with directions of plane and vertical stories, piloti structures were greatly influenced by higher order modes, so the seismic performances by the time-history analysis were significantly different from by the static pushover analysis.

이 연구는 북한에서 개혁개방이 일어날 가능성과, 개혁개방이 발생하 면 어떤 형태를 띨 것인지에 대하여 분석한다. 김정은 집권 이후를 연 구범위로 설정하고, 북한을 둘러싼 국제정치, 북한 주민의 아래로부터 의 개혁, 그리고 고위 엘리트층의 변혁이라는 세 가지 측면에서 가능성 을 예측한다. 주요 결론은 국제정치와 북한 주민의 관점에서 점진적 개 혁개방의 가능성이 현저히 낮으며, 엘리트 내부 균열에 의한 우발적 체 제 변화 가능성이 가장 높다는 것이다. 이 연구를 통해 대한민국과 국 제사회의 대북정책 방향 설정에 함의를 제공하고, 구체적으로 한국의 정책적 대응 전략을 제시하며, 통일과 안보 의제에 실질적인 분석을 제 공한다.

We investigated the effect of band gap engineering on the thermoelectric properties of n-type Cu0.008Bi2Te3 using the two-band (TB) model. The experimental measurements showed a zT of ~0.41 at 300 K and ~0.46 at 520 K, with an optical band gap of ~0.13 eV. While fixing the density-of-state effective mass (md *), deformation potential (Edef), lattice thermal conductivity (κl), and Fermi level based fitted based on experimental data, we varied the band gap (Eg) from 0.1 to 0.3 eV to analyze its impact on the thermoelectric performance. The TB model calculations revealed that the power factor (PF) increased and the thermal conductivity (κ) decreased with increasing Eg at both 300 K and 520 K, leading to an enhancement in zT. The magnitude of this enhancement was more pronounced at 520 K than at 300 K, which can be attributed to the suppressed bipolar effects at higher temperatures. Our findings suggest that increasing the band gap of Cu0.008Bi2Te3 can significantly improve its thermoelectric performance, to an estimated maximum zT of ~0.61 at 520 K for Eg = 0.3 eV. The theoretical maximum zT, considering the optimized hole concentration (nH), was estimated to be ~0.75. We demonstrate that Eg engineering of narrowbandgap semiconductor thermoelectric materials can significantly enhance thermoelectric performance.

Various cystic diseases or benign tumors can occur in the jaw, and diagnosis through accurate analysis is essential. In clinical examination, objective tests such as palpation, percussion, and pulp vitality tests are mainly performed on the patient's subjective symptoms, and differential diagnosis is performed by combining radiological and histopathological examinations. This study aims to analyze the incidence rate, location, and recurrence rate of cystic diseases and benign tumors that appear as radiolucent lesions in the jaw. From 2016 to 2020, 1,293 patients diagnosed with cystic diseases or benign tumors with radiolucent radiographic features in Pusan National University Hospital were identified. Under general anesthesia, patients were subjected to cyst enucleation or excision, and the masses were sent for pathohistological examination at the Department of Pathology, Pusan National University Hospital for definitive diagnosis. The incidence rate, location, and recurrence rate of the diseases mentioned above were analyzed. 1,293 patients were diagnosed, with dentigerous cysts being the most common, followed by radicular cysts, odontogenic keratocysts (OKC), and ameloblastomas. Most ameloblastomas, dentigerous cysts, and OKCs were located in the mandibular posterior region, whereas radicular cysts were predominantly observed in the maxillary anterior region. Recurrence was most notable in ameloblastomas and OKCs. Dentigerous cysts are the most common radiolucent jaw lesions, while ameloblastomas and OKCs show high recurrence rates, thus requiring careful management. The lesions vary in their predominant locations, with ameloblastomas, dentigerous cysts, and OKCs commonly occurring in the mandibular posterior region, and radicular cysts in the maxillary anterior region. Given the differences in recurrence rates and site predilections, it is crucial to differentiate these lesions accurately based on their characteristics and provide appropriate treatment tailored to each type.

The purpose of this study was to provide basic data for evaluating the reproductive health of bivalves using intersexuality. We analyzed purplish bifurcate mussel Mytilisepta virgata (n = 67, shell height 37.1±8.3 mm), Manila clam Ruditapes philippinarum (n = 288, shell length 28.6±4.2 mm) collected from coastal water near Yeosu, Korea. The sex ratio (female:male) of M. virgata and R. philippinarum were 1:1.5 and 1:0.8, respectively, and showed differences depending on the collection area. The total intersexuality of M. virgata was 20.9%. The intersexuality in female (33.3%) was higher than in male (12.5%), and the regional intersexuality was 72.7% in Sogyeongdo, 20.0% in Oesamdo and 5.6% in Jungsamdo with the highest in Sogyeongdo. The total intersexuality of R. philippinarum was 11.8%. The intersexuality in female (17.5%) was higher than in male (4.7%), and regional intersexuality was 20.0% in Neungchodo, 13.0% in Dokdo, 2.8% in Samdo, 5.9% in Orando, 19.6% in Oesamdo with the highest in Neungchodo. The incidence of intersexuality according to distance from cities and ports each sampling area showed no clear tendency. Intersex specimens were showed histological structure changes of digestive gland, such as digestive tubule disruption and necrosis of epithelial cells, accumulation of eosinophilic granules in lumen of tubule, necrosis of connective tissue. These results suggest that not only the histological structure of the digestive gland but also intersexuality should be used as important biomarker for toxicity assessment of pollutants.

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.

현재 국내에서 제조 및 유통되고 있는 209종의 수록 화학염색한지의 색상과 색 특성을 조사하고, 2개사로 부터 오방색과 오방간색과 유사한 화학염색한지의 색 견뢰도를 평가하였다. 현재 유통되고 있는 국내 화학염색한지는 먼셀의 10색상이 모두 있었으며, R과 YR 계열 색상이 각각 17 %로 가장 많았고, 이어 Y (15 %), RP (13 %), PB (11 %), GY (10 %), P (5 %), G (5 %), B (3 %), BG (3 %) 계열의 순으로 청색계열의 색상이 가장 적었다. R, YR, G, B, RP 계열의 화학염색한지는 각 계열의 거의 모든 색상의 한지가 제조되고 있었으나, BG, PB, P계열 화학염색한지 의 색상범위는 다른 색상의 화학염색한지 보다 좁았다. 2개사의 오방색과 오방간색 화학염색한지에 대하여 72시간 자외선 조사처리에 의한 색 견뢰도를 평가하였다. 72시간 자외선 조사에 의해 색상이 변한 것은 B사의 자색 화학염색한지의 색상이 9.9RP에서 1.1R로 변한 것 외에는 없었다. 오방색과 오방간색의 화학염색한지에 대해 72시간 자외선 조사 후의 색차는 황색(btY) >> 벽색(btB), 유황색(mY) > 녹색(myG), 홍색(vpR), 자색(dpR) > 적색(srO) > 청색(sB) > 흑색(Bk), 백색(미염색한지 : Wh)의 순이었다. 오방색과 오방간색으로 화학염색한 한지안에서의 색 견뢰도는 황색이 가장 좋지 않으며, 흑색과 백색이 우수하였다.

본고는 피터 무어가 찍은 백남준의 <필름을 위한 선> 퍼포먼스와 에릭 크롤이 찍은 <TV 부처> 전시에서의 기록사진을 살피며, 미술 아카 이브에서 작품과 함께 등장하는 작가 모습을 담은 사진이 작가가 화면과 어떠한 관계를 맺고자 하는지 발견케 한다는 점을 논한다. 이들은 작가가 자신의 작업과 마주하는 순간을 담은 단편적 기록일 수 있으나 그것은 작가 자신이 화면과 마주하는 의도된 시선과 태도를 드러낸다. 이후 본고는 이를 작품과 감상자(작가)가 연합된 객체를 구성한다는 하먼의 예술객체 개념 하에 살피며, 이런 혼성객체 내부에서 지각자와 감각객체의 '진솔한 몰입'은 예술경험을 들여다 볼 수 있는 기회를 제공한다고 본다. 이를 통해 본고는 기록사진이 제1관객이자 모범적 관객으 로서의 작가가 어떠한 태도로 작품과 함께하며 작품과 진솔한 관계를 맺는지 살필 수 있는 기회를 제공함을 주장하며, 이는 결국 사진을 보는 이들과 해당 작품의 미래 관객에게 작품을 더욱 깊이 이해하고 해석할 수 있는 일종의 형식과 틀을 제시한다고 말하고자 한다. 이러한 주장은 하먼의 예술객체를 감상자뿐 아니라 생산자이자 창작자까지 포함하여 탐색하려는 시도이기도 하다.

본 연구는 종밋 Arcuatula senhousia의 생식생태학적 기초자료와 생물자원의 관리를 위한 정보를 제공하기 위해 수행하였다. 시료는 벌교읍 여자만에서 2019년 6월부터 2020년 5월까지 채집하여 분석하였다. 생식소는 다수의 생식소형성소낭으로 구성되었다. 성비 (암:수)는 1:1.1 (n=128:140, 암컷 46.4%)였으며, 각장이 증가함에 따라 수컷의 비율이 높아지는 경향을 보였다. 생식소지수는 암, 수 모두 5월에 연중 최고값을 보인 후 급격히 감소하여 11월부터 이듬해 1월까지 1.0 이하의 낮은 값을 보였다. 육중량비는 생식소지수와 유사한 경향을 보였다. 월별 생식소발달단계의 변화는 비활성기 (1-2월), 초기활성기 (3-4월), 후기활성기 (4-5월), 완숙기 (5-6월), 방출기 (6-8월), 퇴화기 (9-1월)였다. 종밋의 생식소 활성은 암컷과 수컷 모두 하계에 높고, 동계에 낮은 뚜렷한 계절적 변화를 보였으며, 주 산란기는 6-8월로 분석되었다. 종밋 개체군의 암컷과 수컷 모두 최소 72.7% 이상이 각장 10.1 mm 이상에서 성숙하였으며, 50% 군성숙 크기는 각장 약 10.0 mm로 분석되었다.

This paper explores a convergent approach that combines advanced informatics and computational science to develop road-paving materials. It also analyzes research trends that apply artificial-intelligence technologies to propose research directions for developing new materials and optimizing them for road pavements. This paper reviews various research trends in material design and development, including studies on materials and substances, quantitative structure–activity/property relationship (QSAR/QSPR) research, molecular data, and descriptors, and their applications in the fields of biomedicine, composite materials, and road-construction materials. Data representation is crucial for applying deep learning to construction-material data. Moreover, selecting significant variables for training is important, and the importance of these variables can be evaluated using Pearson’s correlation coefficients or ensemble techniques. In selecting training data and applying appropriate prediction models, the author intends to conduct future research on property prediction and apply string-based representations and generative adversarial networks (GANs). The convergence of artificial intelligence and computational science has enabled transformative changes in the field of material development, contributing significantly to enhancing the performance of road-paving materials. The future impacts of discovering new materials and optimizing research outcomes are highly anticipated.

PURPOSES : Driving simulations are widely used for safety assessment because they can minimize the time and cost associated with collecting driving behavior data compared to real-world road environments. Simulator-based driving behavior data do not necessarily represent the actual driving behavior data. An evaluation must be performed to determine whether driving simulations accurately reflect road safety conditions. The main objective of this study was to establish a methodology for assessing whether simulation-based driving behavior data represent real-world safety characteristics. METHODS : A 500-m spatial window size and a 100-m moving size were used to aggregate and match the driving behavior indicators and crash data. A correlation analysis was performed to identify statistically significant indicators among the various evaluation metrics correlated with crash frequency on the road. A set of driving behavior evaluation indicators highly correlated with crash frequency was used as inputs for the negative binomial and decision tree models. Negative binomial model results revealed the indicators used to estimate the number of predicted crashes. The decision-tree model results prioritized the driving behavior indicators used to classify high-risk road segments. RESULTS : The indicators derived from the negative binomial model analysis were the standard deviation of the peak-to-peak jerk and the time-varying volatility of the yaw rate. Their importance was ranked first and fifth, respectively, using the proposed decision tree model. Each indicator has a significant importance among all indicators, suggesting that certain indicators can accurately reflect actual road safety. CONCLUSIONS : The proposed indicators are expected to enhance the reliability of driving-simulator-based road safety evaluations.

PURPOSES : This study aimed to develop a quantitative structure property relationships (QSPR) model to predict the density from the molecular structure information of the asphalt binder AAA1, a non-full connected structure mixed with a total of 12 molecules. METHODS : The partial least squares regression (PLSR) model, which models the relationship between predictions and responses and the structure of these variables, was applied to predict the density of a binder with molecule descriptors. The PLSR model could also analyze data with collinear, noisy, and multiple dimensional independent variables. The density and additive-free AAA1 binder’s molecule systems generated by an asphalt binder’s molecules-related study were used to fit the PLSR model with the molecular descriptors produced using alvaDesc software. In addition to developing the relationship, a systematic feature selection framework (i.e., the V-WSP- and PLSR-modelbased genetic algorithm (GA)) was applied to explore sets of predictors which contributed to predicting the physical property. RESULTS : The PLSR model accurately predicted the density for the AAA1 binder’s molecules using the condition of the temperature and aging level (R2 was 0.9537, RMSE was 0.00424, and MAP was 0.00323 for the test data) and provided a set of features which correlated well to the property. CONCLUSIONS : Through the establishment of the physical property prediction model, it was possible to evaluate the physical properties of construction materials without limited experiments or simulations, and it could be used to comprehensively design the modified material composition.

We compared the reproductive performance, non-productive performance, and milk composition performance of two groups of lactating cows that were either rice straw or tall fescue. We also compared and analyzed these parameters after the first parturition during the breeding period. The calving interval, artificial insemination, and duration from calving to conception were longer in the rice straw group than in the tall fescue group. The 305-day and peak milk yields were significantly higher in the tall fescue group than in the rice straw group (p<0.01). Milk fat content was significantly higher in the tall fescue group than in the rice straw group (p<0.001), but milk protein content was the same between the feeding groups. The difference in raw milk sales income between rice straw and tall fescue groups tended to increase as the number of lactations increased, but there was no effect of reduced feed costs. Analysis of the milk production and raw milk sales income of the surveyed farms revealed that the average milk production per head was significantly (p<0.05) higher in the tall fescue group than in the rice straw group, and raw milk sales income showed a similar tendency. Overall, these results provide important details to be considered when selecting feed as a way to reduce milk production and heifer raising costs. However, there remains a need for future follow-up studies exploring the relationship between feed choice and the management of heifers.

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.