The purpose of this study is to experimentally analyze the seismic performance of column with RSB (Replaceable Steel Brace), a steel brace system with slot length as a variable. To evaluate the seismic performance of the RSB, three specimens were manufactured and subjected to cyclic loading tests. The length of the sliding slots were considered to be 5 mm and 10mm to enable the brace to resist the load from the initiation of flexural crack and shear crack. As a result of the test, the specimen reinforced with the RSB showed improved maximun load and effective stiffness, and energy dissipation capacity compared to the non-reinforced specimens. The specimens with 5mm sliding slot showed little difference in test result compared to the specimen with a 10mm sliding slot, indicating that the length of sliding slot has little influence on the effectiveness of RSB.
This study presents an analysis of bycatch data concerning Pacific white-sided dolphins (Lagenorhynchus obliquidens) along the Korean coast from 2016 to 2021. A total of 503 bycatches were examined, encompassing data on year, month, body length, sex, latitude (N), longitude (E), and fishing gear. Bycatch was the most frequent in waters with a longitude of less than 130°E, particularly in the southern coastal region at a latitude of 35.5°N, with a higher likelihood of bycatch in lower latitudes. Since 2017, a decreasing trend in bycatches has been observed. The sex distribution of bycaught dolphins showed a predominance of males (40%), followed by females (31%), with an unclassified category at 29%, though no statistically significant differences were found (p > 0.05). Seasonal analysis indicated that bycatch predominantly occurred during the winter months, with significant monthly variations (p < 0.01). Pacific white-sided dolphins were primarily ensnared in gill nets and, to a lesser extent, in stationary nets. Statistical analysis by gear type revealed a significant preference for gill nets (p < 0.001). Considering body length composition in relation to latitude, it is suggested that Pacific white-sided dolphins may utilize the southern waters of the East Sea as a potential nursery ground, though this was not confirmed at a significant level, emphasizing the need for further in-depth monitoring and ecological investigations. Given that there are approximately 27 different types of gill nets associated with the majority of bycatches, more detailed research is warranted to divide these gear types into finer subcategories for estimating bycatch relationships, ultimately leading to the development of effective conservation and management strategies.
Silkworms have been developed for food and medicinal purposes, and several silkworm products are commercially available. However, there has been no research on their shelf stability. This study investigated the shelf stability of freeze-dried silkworms during storage at various temperature and humidity conditions, using three lipid oxidation indicators: peroxide, acid, and TBA value. The higher the temperature and relative humidity are, the more significant the three lipid oxidation indicators increase. Among these indicators, the TBA and peroxide values show the highest temperature dependence and humidity dependence, respectively. This study could contribute to the standardization of the shelf life of products made from freeze-dried silkworms.
Long term variations of fish assemblage in the coastal waters of Bukchon-ri were determined using samples collected by trammel net from 2012 to 2022. Water temperature increased by 0.4℃ in 2022 that was less then 2012. During the survey period, a total of 95 species (53 families and 15 orders) of fishes were identified, Scorpaeniformes (five families and 22 species) and Perciformes (25 families and 39 species) accounted for 73% of the total number. The number of species was higher in summer than winter, showing a peak in summer at 66 species and lower in winter and autumn at 45 species. The number of individuals and the biomass peaked in summer at 1,238 individuals and 280.1 kg, and were the lowest in autumn at 597 individuals and 155.4 kg. The annual diversity index, evenness index and richness index were appeared 2.11-2.80, 0.64-0.80 and 4.70-7.34 at each years. The dominance index were appeared highest in 2014 while 2021 were appeared the lowest in 2017. The subtropical fishes were identified total of 38 species (40.0%) and the number of species was higher in 2022 at 22 (52.4%) species and lower in 2015-2017 at each 10 (31.3-37.0%) species. The dominant species of subtropical fishes were appeared rabbit fish (Siganus fuscescens), boxfish (Ostracion immaculatus), smallscale blackfish (Girella melanichthys), flag fish (Goniistius zonatus), stripey (Microcanthus strigatus), rock porgy (Oplegnathus punctatus), and bluestriped angelfish (Chaetodontoplus septentrionalis) in study sites.
Purpose: This study utilizes a phenomenological research method to understand the nature of role adaptation experience of PA nurses. Methods: This was a qualitative study that applied Colaizzi’s phenomenological research method to understand the nature of role adaptation experience of PA nurses. The study participants were thirteen PA nurses (three men and ten women) with over five years of experience. For data collection, individual in-depth interviews were conducted, each about 50 to 90 minutes long. Individual interviews were conducted once or twice. Colaizzi’s method was used to analyze data. Results: The result of this study had 11 clusters of themes and 4 major themes were derived from the analysis: “parallel lines of conflict,”“anxiety about unclear future,”“disorganization of identity,”and “my own way to learn about myself.”These four major themes are structured chronologically to the extent possible but are not mechanically segmented based on time. Conclusion: This study recognizes the seriousness of PA nurses’problems in the absence of research on PA nurses’role adaptation experience and recommends that appropriate research is necessary. Standardized work guidelines and positive awareness of the role of PA nurses are necessary and are supported by PA nurses to establish their position as professionals.
The equivalent static load for non-structural elements has a limitation in that the sloshing effect and the interaction between the fluid and the water tank cannot be considered. In this study, the equations to evaluate the impulse and convective components in the design codes and previous research were compared with the shaking table test results of a rectangular water tank with flexible wall panels. The conclusions of this study can be summarized as follows: (1) It was observed that the natural periods of the impulsive component according to ACI 350.3 were longer than system identification results. Thus, ACI 350.3 may underestimate the earthquake load in the case of water tanks with flexible walls. (2) In the case of water tanks with flexible walls, the side walls deform due to bending of the front and back walls. When such three-dimensional fluid-structure interaction was included, the natural period of the impulsive component became similar to the experimental results. (3) When a detailed finite element (FE) model of the water tank was unavailable, the assumption could be used, resulting in a reasonably conservative design earthquake load.
한국형아유르베다 성격유형과 의류 구매만족과 어떤 관계가 있는지를 분석함으로써 성격특성을 고려한 마케팅 전략에 대해 논의하는 것이다. 본 연구의 자료는 수도권 여성 20대 이상을 대상으로 다음과 같은 통계 분석을 실시하였다. 첫째, 조사대상자의 일반적 특성을 파악하기 위해 빈 도분석을 실시하였고, 둘째, 측정도구의 타당성 분석을 위해 탐색적 요인 분석을 실시하였다. 또한 Cronbach's α 계수를 이용하여 요인을 구성 하는 항목들의 신뢰도를 분석하였다. 셋째, 한국형 아유르베다 기본심리 유형에 대해 알아보고, 조사대상자의 일반적 특성에 따라 차이가 있는지 파악하기 위해 교차분석을 실시하였다. 넷째, 한국형 아유르베다 기본심 리유형에 따라 고객만족에 차이가 있는지를 알아보기 위하여 일원변량분 석(one-way ANOVA) 및 Scheffe의 사후검정을 실시하였다. 본 연구는 한국형아유르베다 기본심리유형과 고객만족의 관계에서는, 전반적인 고 객만족과 하위요인별 서비스만족에 있어서도 카파형(K)이 상대적으로 높 은 것을 알 수 있었지만, 품질만족에 있어서는 통계적으로 유의미한 차 이가 나타나지 않았다는 것을 알 수 있었다.
한반도는 주변국의 안보정세 변화, 북한의 미사일 도발, 병역자원의 급 감, 민간 생활지역 확장으로 훈련장 부족 및 민원증가, 안전사고 등 많은 도전요인에 직면해 있다. 특히 군사대비태세의 근간이라 할 수 교육훈련을 위한 여건은 매우 심각한 수준이다. 이를 극복하기 위해 국방 분야에서는 4차산업혁명 기술을 적용한 LVCG 과학화 훈련체계를 구축하여 추진하고 있다. LVCG 과학화 훈련은 Live 체계(실기동훈련, KCTC), Virtual 체계 (가상현실), Constructive 체계(전투모의), Game 체계(게임) 등을 활용하 여 언제 어디서든지 실전과 같은 훈련 경험이 가능하며, 훈련 결과에 대한 데이터를 활용하여 객관적 평가가 가능하다. 따라서 AI, AR, VR 등 과학기 술의 발달을 기회요인으로 활용하여 체계별 성능을 개량하고 LVCG 체계 를 하나의 환경에서 운용할 수 있는 합성훈련환경(STE)을 구축하여 실전 과 같은 훈련이 되도록 해야 한다.
The objective of this study was to investigate the distribution of functional compounds in perilla leaves of various genetic resources and their antioxidant activities. A comprehensive analysis of functional compounds was conducted for 90 genetic resources, focusing on total polyphenol content (TPC), total flavonoid content (TFC), individual phenolic content (IPC), and lutein. Their antioxidant activities were then analyzed based on their radical scavenging capacity using ABTS (2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) and DPPH (2,2-diphenyl-1-picrylhydrazyl). The TPC content exhibited a range of 13.19 to 35.85 mg gallic acid equivalent/g, whereas the TFC content varied from 11.74 to 46.51 mg catechin equivalent/g. Total IPC was detected in a range of 6,310.98 to 40,491.82 μg/g. Lutein was detected at levels between 70.97 and 597.97 μg/g. ABTS and DPPH radical scavenging activities of perilla leaves ranged from 30.39 to 58.58 mg trolox equivalent (TE)/g and from 7.74 to 46.56 mg TE/g, respectively. Furthermore, correlation analysis demonstrated that rosmarinic acid, a phenolic acid, exhibited a significantly positive correlation with antioxidant activity. These findings suggest that various genetic resource of perilla leaves could effectively mediate antioxidant capacity. Results of this study provide valuable information for use of perilla leaves in Korea as functional food materials.
현대의 방탄 장갑은 우수한 관통 저항성을 갖추어야할 뿐만 아니라 군인과 군용차량의 기동성이 확보되어야 하기 때문에 경량화가 중요한 개발 요소가 되었다. 이종 적층 평판 구조의 방탄 장갑의 방탄 성능은 동일 중량 대비 구성 재료의 배열에 따라 달라진다. 본 논 문에서는 케블라, 초고분자량 폴리에틸렌 그리고 에바 폼으로 구성된 방탄 장갑의 적층 배열에 따른 방탄 성능을 분석한다. 구성 재료 의 두께가 5mm와 6.5mm인 두 가지 경우에서 6가지 적층 배열에 대하여 7.62 × 51mm NATO 탄환의 M80 탄을 856m/s의 속도로 충돌 시키는 피탄 해석을 수행하였다. 방탄 성능을 평가하기 위해 이종 적층 평판을 관통한 발사체의 잔류 속도와 잔류 에너지를 측정하였 다. 시뮬레이션 결과를 통해 케블라, 초고분자량 폴리에틸렌, 에바 폼의 배열 순서를 갖는 적층 구조가 동일 중량에 대해 가장 우수한 방탄 성능을 가짐을 확인하였다.
PURPOSES : This study investigates the factors affecting extra-long tunnel accidents by integrating data on tunnel geometry, traffic flow, and traffic accidents and derives the underlying implications to mitigate the severity of accidents. METHODS : Two processes centered on three key data points (tunnel geometry, traffic flow, and traffic accidents) were used in this study. The first is to analyze the spatial characteristics of extra-long tunnel traffic accidents and categorize them from multiple perspectives. The other was to investigate the factors affecting extra-long tunnel traffic accidents using the equivalent property-damage-only (EPDO) of individual accidents and the aforementioned data as the dependent and independent variables, respectively, by employing an ordered logistic regression model. RESULTS : Gyeonggi-do, Gyeongsangnam-do, and Gangwon-do are three metropolitan municipalities that have a significant number of extra-long tunnel accidents; Busan and Seoul have the most extra-long tunnel accidents, accounting for 23.2% (422 accidents) and 18.6% (339 accidents) of the 1,821 accidents that occurred from 2007 to 2020, respectively. In addition, approximately 70% of extra-long tunnel traffic accidents occurred along tunnels with lengths of less than 2 km, and Seoul and Busan accounted for over 60% of the top 20 extra-long tunnels with accidents. Most importantly, the Hwangryeong (down) tunnel in Busan experienced the most extra-long tunnel traffic accidents, with 77 accidents occurring during the same period. As a result of the ordered logistic regression modeling with EPDO and multiple independent variables, the significant factors affecting the severity of extra-long tunnel traffic accidents were determined to be road type (freeway, local route, and metropolitan city road), traffic flow (speed), accident time (year, summer, weekend, and afternoon), accident type (rear end), traffic law violations (safe distance violation and center line violation), and offending vehicles (van, sedan, and truck). CONCLUSIONS : Based on these results, the following measures and implications for mitigating the severity of extra-long tunnel traffic accidents must be considered: upgrading the emergency response level of all road types to that of freeways and actively promoting techniques for regulating high-speed vehicles approaching and traversing within extra-long tunnels are necessary. In addition, the emergency response and preparation system should be reinforced, particularly when the damage from extra-long tunnel traffic accidents is more serious, such as during the summer, weekends, and afternoons. Finally, traffic law violations such as safe distance and centerline violations in extra-long tunnels should be prohibited.