A seismic intensity map, which describes ground motion distribution due to an earthquake, is crucial for disaster evaluation after the event. The ShakeMap system, developed and disseminated by the USGS, is widely used to generate intensity maps in many countries. The system utilizes a semi-variogram model to interpolate the measured intensities at seismic stations spatially. However, the default semi-variogram model embedded in ShakeMap is based on data from high seismic regions, which may not be suitable for the Korean Peninsula, categorized as a low-to-moderate seismic region. To address this discrepancy, this study aims to develop the region-specific semi-variogram model using local records and a region-specific ground motion model (GMM). To achieve this, we followed these steps: 1) collected records from significant earthquake events in South Korea, 2) calculated residuals between the observed intensities and predictions by the GMM, and 3) created semi-variogram models using weighted least squares regression to better fit short separation distances for PGA, PGV, SA0.2, and SA1.0. We compared the developed semi-variogram models with conventional models embedded in ShakeMap. Validation tests showed that the region-specific semi-variogram model reduced the mean squared error of intensity predictions by approximately 3.5% compared to the conventional model.

This study aimed to identify the selectivity of catches according to mesh size of gillnets, and to collect basic data for fisheries resource management plans for gillnets. The mesh selectivity test was conducted with five different mesh sizes (60, 66, 69, 75, and 96 mm) gillnet in coastal sea of Mukho port and the selectivity was analyzed using the Kitahara method. In results of the selectivity test, a total of 143 (36,249 g) of atka mackerel were caught and the 60 mm gillnet was the highest at 83 (18,596 g), which is about 58.0% of the total catch. The relative growth equation between body length and weight showed that weight tends to increase proportional to body length. The maximum length/mesh size value was showed 0.490 by the master curve of selectivity, and the 50% selection range was showed 0.138. Therefore, it was found that the size of the caught fish increased proportional to the mesh size. The results of this study were intended to be used as data for establishing a plan for efficient management of atka mackerel resources.

Ceramic materials have become essential due to their high durability, chemical stability, and excellent thermal stability in various advanced industries such as aerospace, automotive, and semiconductor. However, high-performance ceramic materials face limitations in commercialization due to the high cost of raw materials and complex manufacturing processes. Aluminum borate (Al₁₈B₄O₃₃) has emerged as a promising alternative due to its superior mechanical strength and thermal stability, despite its simple manufacturing process and low production cost. In this study, we propose a method for producing Al₁₈B₄O₃₃ spherical powder with increased uniformity and high flowability by controlling the particle size of B₂O₃. The content ratio of the manufactured Al18B4O33 spherical powder was Al2O3: B2O3 = 87:13, and it exhibited a 17% reduction in the Hausner ratio (1.04) and a 29% decrease in the angle of repose (23.9°) compared to pre-milling conditions, demonstrating excellent flowability.

목적 : 본 연구에서는 노래의 템포(bpm) 및 데시벨(dB)에 따른 동공 크기 및 동적 조절 변화를 비교하고, 빛의 유무에 따른 차이도 비교해 보고자 한다. 방법 : 연구 대상은 안질환이나 시각 장애가 없는 성인 20명(남자 10명, 여자 10명, 평균연령 24.25±3.99세) 이었다. 완전 교정 상태에서 명소시에서 6 m 거리의 시표로, 암소시에는 무한대 거리로 측정하였다. 두 조건 모두 헤드셋을 착용하여 네 가지 음악 드럼(D), 메탈(M), 외국 팝(F), 클래식(C)을 들었을 때 동공 크기와 조절 반응의 변화를 각각 40 dB 미만, 60 dB 미만, 80 dB 이상으로 측정하여 비교하였다. 결과 : bpm 및 dB에 따른 자극이 있을 때, 유의한 차이를 보였다(p<0.010). 두 조건 모두 동일한 dB에서 bpm 이 달라졌을 때 자극량의 차이는 있었으나, bpm 변화에 따른 동공 크기와 동적 조절 변화량은 유의한 차이가 없었 다. 동공 크기와 동적 조절 변화량을 조도에 따라 비교했을 때, D 장르의 40 dB(p<0.050)과 F 장르의 60 dB (p<0.050)에서 동공 크기 변화량의 차이가 있었다. 조도가 없을 때 동적 조절 변화량이 더 증가하여, bpm과 dB에 따른 모든 그룹에서 유의한 차이가 나타났다(p<0.050). 결론 : 본 연구 결과, 각 노래의 bpm과 dB에 따른 동공 크기와 동적 조절 변화는 자극의 유무에 따라 영향을 받는 것으로 확인되었다. 특히, 암소시에서는 동적 조절 변화에 더 큰 영향을 미쳤으며, 명소시에서는 동공크기 변 화가 컸다.

목적 : 누진 가입도 안경 착용자의 안경테의 크기와 얼굴 형태에 적합한 안경테를 비교하여 안경테 크기와 신체 적(역학적) 불편감 사이의 연관성을 조사하였다. 방법 : 누진 가입도 안경 착용자 중 안경의 피팅 상태가 적절한 71명(남성 37명, 여성 34명, 평균 54.52±8.78 세)이 참여하였고, 신체적 불편감을 설문지로 조사하였다. 안경테 크기를 FHD(front horizontal dimension), FTB(front to bend), LOD(length of drop) 및 TL(temple length)로 확인하였다. 얼굴 형태를 계측한 후 얼굴에 적합한 안경테 크기를 계산하였고, 착용하고 있는 안경테 크기와 비교하였다. 결과 : 신체적 불편감의 정도는 관자놀이 눌림, 흘러내림, 코 눌림, 귀 눌림 순으로 높았으며, 불편함을 경험한 비율은 흘러내림, 코 눌림, 귀 눌림, 관자놀이 눌림 순으로 높았다. 착용한 안경테의 FHD는 남녀 모두 얼굴 계측 으로 계산한 안경테 설계값보다 작았다(p=0.001). 착용한 안경테의 FTB는 남녀 모두 안경테 설계값보다 작았으 며, 착용한 안경의 LOD는 설계값보다 컸고 여성은 남성보다 길었다(all, p=0.001). 결론 : 착용한 남녀 안경의 FHD는 얼굴 형태에 비해 작아 관자놀이 눌림의 원인이 될 수 있고, 측면부 LOD는 얼굴에 비해 커서 흘러내림과 코 눌림의 원인이 될 수 있다. 얼굴 형태에 적합한 안경테 크기를 선택할 수 있도록 안경테의 FHD와 측면부 전체 길이(FTB+LOD)가 여러 사이즈로 제작되어야 할 것이다.

자기공명영상 평가 시 정확한 영상평가를 방해하는 요인에는 여러 가지가 있다. 그중 측정자로 인한 관심 영역의 크기 설정도 여러 요인 중 하나인데, 아직 다른 요인에 비해 관심 영역의 크기 설정은 연구가 부족한 실정이다. 이에 본 연구에서는 관심 영역의 크기 변화에 따른 SNR의 변화를 통계적으로 비교·분석하여 설정하는 방법을 제시하고 그 유용성을 증명하고자 하였다. 연구 방법은 팬텀의 T1, T2 강조영상을 획득한 다음 획득한 영상에 관심 영역의 크기를 변화시켜 신호강도를 측정한 후 관심 영역의 크기 변화에 따른 SNR 산출하여 비교평가 하였다. 연구 결과 T1 강조영상은 관심 영역의 크기 설정 시 20% 이하, T2 강조영상은 40% 이하로 설정할 때 기준 관심 영역 크기와 SNR이 통계적으로 차이가 없었다. 결론적으로 관심 영역의 크기 설정 시 본 연구의 통계를 이용한 설정 방법을 적절히 활용하여 측정을 시행한다면 관심 영역 크기 설정의 합리적 근거를 마련할 수 있어 유용하리라 판단된다.

This study determined the minimum size of a representative molecular structure for use in future dynamic analyses of asphalt binders. The minimum representative size, considering factors such as aging, additive types, and temperature variations, was established using density and radial distribution functions. This approach ensures that the structure reflects temperature-dependent property changes, which are critical characteristics of asphalt binders. In this study, the structure of asphalt-binder molecules was generated using the composition proposed by Li and Greenfield (2014) for AAA1. To assess the appropriateness of the molecular structure size, we generated additional structures, X2 and X3, maintaining the same composition as X1, but with two and three times the number of molecules, respectively, as suggested by Li and Greenfield (2014). Silica and lignin were considered as additives, and the aging conditions examined included unaged, short-term aging, and long-term aging. In addition, 11 temperature conditions were investigated. The density and radial distribution functions were plotted and analyzed. The variables influencing the density and radial distribution functions were set as the aging degree of the asphalt binder (unaged, short-term aging, long-term aging), 11 temperature conditions ranging from 233 to 433 K in 20 K intervals, structure size (X1, X2, and X3), and the presence of additives (no additives, silica, and lignin). For density, clear differences were observed based on the degree of aging, temperature conditions, and presence of additives, whereas the structure size did not significantly affect the density. In terms of radial distribution functions, the X1 structure reflected differences based on the degree of aging and the presence of additives but was limited in exhibiting temperature-dependent variations. In contrast, the X3 structure effectively captured temperature-dependent trends, indicating that the size of the molecular structure is crucial when evaluating energy calculations or physical tensile strength, necessitating careful assessment.

그래핀 산화물(GO), 폴리에틸렌 글리콜 다이아크릴레이트(PEGDA), 폴리에틸렌 글리콜 메틸 에터 아크릴레이트 (PEGMEA)의 나노복합체를 자외선 광중합을 통해 합성하였다. GO는 가교된 폴리에틸렌 옥사이드(XPEO) 매트릭스 내에 최 대 1.0 wt% 농도까지 균일하게 분산시켰다. 더 높은 농도에서는 GO가 응집되는 경향을 보였다. 잘 분산된 GO는 친수성 PEO 사슬과 추가적인 화학적 가교 네트워크를 형성했다. XPEO-GO 나노복합체는 GO 농도에 따라 기계적 강도 및 염과 가 스에 대한 차단 특성이 향상된 것으로 나타났다. 이 연구는 다양한 GO 농도와 플레이크 크기를 가진 XPEO-GO 하이드로겔 의 제조 및 특성화를 다루고 있다. 이러한 특성은 나노복합 하이드로겔이 강화된 XPEO 기반 바이오소재 및 고급 항균성 한 외여과(UF) 친수성 코팅에서의 잠재적 응용 가능성을 시사한다.

The Occupational Safety and Health Act (OSHA) aims to maintain and promote the safety and health of workers. Additionally, violations of the act can result in imprisonment or fines, depending on the severity of the offense. This study examines whether the severity of OSHA violations is proportional to the size of the fines imposed. There are 120 items subject to fines, with penalties ranging from a minimum of 50,000 won to a maximum of 30 million won. To assess the severity of these items, pairwise comparisons were conducted, and the results were expressed numerically. In summary, no significant correlation was found between the severity of violations and the amount of the fines. Therefore, this study proposes calculating fines based on the severity of violations. In many small companies, resources (e.g., budget and manpower) are limited. Thus, greater attentions tend to be directed toward addressing items with higher fines. Consequently, aligning the severity of legal violations with the size of the fines may contribute to improving the industrial safety.

A sirocco fan consists of a housing and an impeller with blades. There are many design parameters for improving its performance and efficiency. Thus, the objective of present study is to investigate the effect of blade size(such as blade length and height) and the number of blades on the flow characteristics of a sirocco fan using a commercial CFD software, Star CCM+. From the results of our previous and present study, it is revealed that blade inclination angle and blade height had a great effect on the flow characteristics, such as the static pressure rise and flow rate. There are important factors in improving the flow characteristics, as following order, the blade inclination angle, blade height, blade length, blade radius of curvature, the number of blades. it was obtained that maximum in static pressure rise and flow rate were, respectively, 20.8Pa and 6.41CMM under the our simulation condition.

To analyse and review the fishing performance and species composition according to the size of the entrance and mesh of the pot in the southern coastal waters (Tongyeong, Gyeongsangnam-do and Yeosu, Jeollanam-do), the experiment in this study caught one class, eight orders, 17 families, 23 species, 662 fishes, and 99,833 g. The largest number of fish species was Conger myriaster (301 fishes caught) accounting for 45.5%, followed by Octopus vulgaris (152) accounting for 23.0%, Charybdis japonica (45) accounting for 6.8%, Sebastiscus marmoratus (43) accounting for 6.5%, and Parapercis sexfasciata (42) accounting for 6.3%. Conger myriaster, Octopus vulgaris, Charybdis japonica, Sebastiscus marmoratus, and Parapercis sexfasciata accounted for 88.1% of the total catch. For other fish species, 68 fishes of 18 species were caught, accounting for 12.5% of the total. As a result of the total catch survey, the catch rate of Conger myriaster was the highest at 50.9% in B. 22 mm/280 mm. In addition, the average total length per fish increased as the entrance size increased. The weight ratios of Conger myriaster, Octopus vulgaris, and other fish species based on the total weight caught in each pots of the six species of test fishing gear are as follows. A pots 66.6%, 26.5%, 6.9%, B pots 57.2%, 24.5 %, 18.3%, C pots 43.2%, 31.5%, 25.3%, D pots 7.4%, 56.7%, 35.9%, E pots 43.6%, 0%, 56.4%, and F pots 5.0%, 79.6%, 15.4%.

WAAM(Wire Arc Additive Manufacturing) has gained attention as an innovative technology in small-batch, multi-product production due to its advantages of low production costs, rapid build rates, and design flexibility. However, challenges such as relatively low geometric accuracy, surface finish defects, residual stresses, and distortion due to high heat input persist and require improvement. This study analyzes the influence of deposition path angles on deposition performance in the WAAM process. Experiments were conducted using stainless steel (STS309MoL) wire, known for its excellent heat resistance and corrosion resistance due to its relatively high ferrite content within the austenitic structure. To mitigate residual stresses and distortion caused by high heat input, the CMT(Cold Metal Transfer) process was employed for five layers of deposition. Five different deposition path angles were selected as process variables, and the impact of deposition path angles on deposition performance was evaluated based on experimental results.

This study presents a fine scale distribution of the endangered species, Odontobutis obscura, through field surveys and literature reviews. Using the mark-recapture method, the population size in major habitats was determined. Field surveys conducted on 18 streams in Geoje Island revealed that the O. obscura was only found in the main streams and tributaries of the Sanyang, Gucheon, and Buchun Streams, which are part of the Sanyang Stream watershed. The O. obscura exhibited relative abundances ranging from 0.5% to 35.3% at different locations, with certain spots showing higher relative abundances (18.8% to 35.3%), indicating major habitat areas. A review of six literature studies confirmed the presence of the O. obscura, although there were differences in occurrence status depending on the purpose, scope, and duration of the studies. Combining the results of field and literature surveys, it was found that the O. obscura inhabits the main and tributary streams of the Sanyang, Gucheon, and Buchun Streams, from the upper to lower reaches. Currently, the O. obscura population in the Sanyang Stream watershed maintains a stable habitat, but its limited distribution range suggests potential issues such as genetic diversity deficiency in the long term. The population size of the O. obscura was confirmed at two specific locations, with densities of 0.5 to 1.5 individuals per m2. The average movement distance from the release point was 13.1 m, indicating the limited mobility characteristic of ambush predators. Understanding the distribution and population size of endangered species is the first step towards their conservation and protection. Based on this information, further research could significantly contribute to the conservation of the O. obscura.

갯까치수염은 다육성의 2년생 초본 자생식물로서, 제주도, 울릉도를 비롯하여 남해안 지역에서 자라며 자생지의 환경에 맞게 내염성이 크다는 특징이 있고, 다양한 환경에 적응하며 관상가치가 높다. 관련 문헌을 보면 발아조건과 개화조절에 대한 연구만 보고되었고 그 중간단계인 재배에 관한 연구가 부족하여 대량생산을 위한 공정육묘법 개발의 일환으로 이 실 험을 수행하였다. 실험은 플라스틱온실 내에서 발아시킨 1cm 전후의 묘를 50, 128, 200구 트레이에 이식하여 한국원시표 준액(N-P-K-Ca-Mg, 15-3-6-8-4)을 각각 권장 EC농도의 0, 0.5, 1, 2배 농도로 매일 5분간 순환식으로 저면 관수하여 6주간 재배 후 초장, 근장, 엽수, 뿌리수, SPAD, 생체중, 건물 중을 측정하였다. 갯까치수염 생육은 플러그 셀 크기 50셀에 서 생육이 가장 높았다. 양액농도에 따른 갯까치수염의 생육 은 0.5배액에서 초장과 근장의 수치가 가장 높았으며, 모든 생육지표가 양액 농도변화에 따른 차이가 발생하는 것으로 나 타났고 실질적인 총 생산량의 지표라고 할 수 있는 지상부와 지하부의 건물중에 영향을 미치지 않았다는 결과가 나온 것으 로 미뤄 육묘단계에서 양액의 농도가 셀 크기보다 갯까수치염 의 묘 생육에 더 영향이 큰 것으로 보인다. 갯까치수염의 조직 충실도 면에서 0.5, 1, 2배액의 200구에서 가장 높은 결과값 들이 나왔다. 결과적으로 기존 원시표준액에 비해 생장에 유 리한 결과를 보이며 비료도 절약할 수 있는 0.5배 양액처리조 건이 갯까치수염 육묘 재배에 더 효율적이였다.