The study on the efficiency improvement of qualification procedures for low Earth orbit (LEO) satellites analyzed the differences between the European ECSS and the American NASA standards. ECSS allows flexible test tailoring to accommodate project-specific requirements, whereas NASA enforces strict standardized procedures to ensure high reliability. Additionally, ECSS prioritizes cost efficiency, while NASA emphasizes reliability. In terms of application scope, NASA focuses on private-sector collaborations, whereas ECSS is centered on cooperative projects within Europe. Based on this comparative analysis, this study proposes a qualification framework for Korean LEO satellites, categorizing 18 qualification test items into mandatory and optional groups. This approach is expected to enhance the reliability, performance, and stability of satellite systems. Therefore, the proposed Korean qualification test sequence should be implemented and incorporated into national defense standards. This will strengthen the systematic structure of the qualification process while maximizing efficiency in terms of testing time and cost.

This study explored factors affecting variability in second language (L2) learning motivation among Korean university students and how they appraised their L2 learning experience. In this study, 85 undergraduate students majoring in English or English education from three universities in Seoul, South Korea, reflected on their past English learning experience. They drew a motigraph and wrote a retrospective reflection essay covering their English learning that spanned over ten years. Researchers divided participants into two groups: a high variability (HV) group and a low variability (LV) group. Data were analyzed using open, axial, and selective coding. Findings suggest thncontextual factors such as the learning method, atmosphere, and situation were main (de)motivational factors for the HV group. In contrast, the LV group was (de)motivated by intrapersonal factors, including the learning context appraisal. These results imply that visualizing long and short-term goals and positive appraisal of the L2 learning experience can help L2 learners maintain a stable pattern in L2 learning motivation.

본 연구에서는 저온 스트레스에서 살리실산(SA, salicylic acid)의 경엽처리가 배추의 광합성, 생리활성 및 생육에 미치는 영향을 구명하고자 하였다. SA을 각각 0.25, 0.5 및 1mM 농도로 주당 100mL을 4일 간격으로 3회 엽면 살포하였고, 7일간 저온 스트레스를 처리하였다. SA 처리 시 광합성 속도, 기공전도도, 세포 내 CO2 농도 및 증산 속도는 무처리 대비 증 가하였고, 2회 처리 후 가장 높았다. MDA 함량은 무처리 대 비 유의한 차이를 보이며 감소하였다. APX, CAT, POD 및 SOD 활성은 무처리 대비 현저하게 증가하였으며, 각각 최대 62, 81, 55 및 26% 증가하였다. 배추의 생육 특성은 무처리와 유의한 차이를 보이지 않았으나, 수량 지수는 2－6% 정도 증 가하였다. 따라서 SA의 경엽처리는 배추의 생육, 광합성 특성 및 항산화 효소 활성을 증대시켜 저온 스트레스를 완화 하였 고, 적정농도는 0.5－1mM이라 판단된다.

Background: When shorter muscles are restored to normal, non-specific low back pain, which is the mechanism that causes pain along with muscle relaxation, disappears. Among the stretching methods, self-stretching is a good exercise method not only for treatment but also for preventive purposes. Objectives: To find out what is the most effective method of self-stretching, which is often used in treatment and preventive arbitration, which can reduce muscle activity and increase spinal flexibility in patients with non-specific back pain. Design: Randomized controlled trials. Methods: Three self-stretching exercise methods for erector spinae are randomly assigned to 13 people each, and three self-stretching exercise methods are performed for each study subject. Surface electromyography using, was performed to measure the erector spinae muscle activity. flexibility was measured through Trunk flexion test in a standing position. Muscle activity and flexibility were measured before and after stretching. Results: The difference in muscle activity and flexibility in the three groups, including cat stretching, seated stretching, and Reclining stretching, all showed statistically significant differences. There was no statistically significant difference in comparison between the three groups of stretch muscle activity. However, a statistically significant difference was shown in the comparison of the variability between the three groups of flexibility. In a post-mortem analysis comparing the amount of change in flexibility, the flexibility of the seated stretching in the chair increased significantly compared to the cat stretching group. Conclusion: It can be confirmed that the stretching method of the erector spinae, cat stretching, seated stretching, and Reclining stretching, all have positive effects on muscle activity and flexibility.

Background: In patients with low back pain (LBP), weakened core muscles and impaired proprioception contribute to decreased spinal stability and LBP recurrence. Objectives: To investigate the effects of abdominal bracing exercises (BE) and kinetic link training (BEKLT) on pain, balance, and proprioception in LBP patients. Design: Randomized controlled trial. Methods: Sixteen adults with LBP were randomly assigned to a BE group or a BEKLT group. Both groups completed a four-week intervention (three sessions per week). Pain was assessed using the visual analog scale (VAS), proprioception with the lumbar reposition sense test, and balance with the BT4 system. Results: Both groups showed significant reductions in VAS and proprioception error (P<.05), with no inter-group differences. In dynamic balance (limits of stability), the BE group improved in rearward, left, and right angles, while the BEKLT group improved in forward, rearward, and left angles (P<.05). A significant difference was observed in the forward leaning angle between groups (P<.05). For static balance, both groups showed significant reductions in trace length and C90 area (P<.05), with no inter-group differences. Conclusion: The findings suggest that both BE and BEKLT are effective interventions for reducing pain and improving proprioception and balance in LBP, with BEKLT providing additional benefits for dynamic balance.

The recent release of contaminated water from the Fukushima Daiichi Nuclear Power Plant highlights the need for accurate tritium measurement, particularly near the minimum detectable activity (MDA) of 5 Bq·L−1 set by South Korea’s Nuclear Safety and Security Commission. This study aims to improve low-level tritium measurement accuracy by optimizing the region of interest (ROI) for quench curve determination. These adjustments are crucial for separating tritium signals from background noise. Quench standards were prepared and measured using a liquid scintillation counter (LSC). Three ROIs were analyzed to assess the impact of channel selection on measurement precision: A 20-148 channel range optimized via figure of merit (FOM) analysis, a 20-250 channel range covering tritium’s full beta spectrum, and a broad 1-1024 channel range. Quench curves were obtained by fitting the counting efficiency of each ROI to the quench standards. Tritium samples with six different activity levels were prepared, and their radioactivity was calculated using the quench curves. Selecting appropriate ROIs for quench curve determination is critical for measuring low-concentration tritium accurately. This approach reduces uncertainty and emphasizes reliable methods to improve the precision and consistency of tritium measurements.

목적 : 본 연구는 중국 안과병원에 방문한 저도와 중등도 근시 청소년을 연구 대상으로 각막굴절교정 렌즈에 의한 단기간의 근시 진행 억제 효과가 있는지 관찰하고자 하였다. 방법 : J안과에 방문한 근시환자 중 40명의 환자 저도 근시군 20명(40안), 중등도 근시군 20명(40안)을 대상으 로 각막굴절교정 렌즈를 처방하고 6개월 동안 추적 관찰하였다. 각막굴절교정 렌즈 착용 후 1개월, 3개월, 6개월 후 각각 각막굴절교정 렌즈 교정 후 시력과 안축의 길이, 각막곡률, 안압, 각막 중앙 두께 등을 검사하여 분석 및 비교하였다. 통계분석은 SPSS 27.0 소프트웨어를 사용하였다. 결과 : 저도근시군과 중등도근시군의 교정시력이 모두 향상되었으며, 두 군 간의 차이는 통계학적 으로 유의하 였으며, 안축 길이는 중등도근시군의 안축 성장이 작았고, 두 군 간의 차이는 통계학적으로 유의하였다. 각막 곡률 은 중등도 근시 군의 각막 곡률이 더 많이 감소했으며, 두 군 간의 차이는 통계적으로 유의했다. 각막굴절교정 렌 즈를 착용한 환자는 안압과 각막 중앙 두께 측면에서 기준치와 유의한 변화가 없었다. 결론 : 각막굴절교정 렌즈는 청소년의 근시를 효과적으로 교정되었으며, 근시 진행을 억제하는 방법 중 하나로 근시 정도에 따라 차이가 있었다. 또한 청소년들의 근시 통제 효과는 중등도 근시 환자가 저도 근시 환자보다 더 효과적이었다.

본 연구는 일본의 저출산 문제에 대한 정책적 대응이 어떤 경로로 형성 되고 변화되었는가의 과정을 역사적 제도주의 관점에서 분석한 것이다. 이를 위하여 저출산 정책이 형성된 1990년대 초 엔젤플랜에서 2003년 소자화사회대책기본법의 입법화가 이루어지는 시기에 집중하여 살펴보았 다. 이를 통한 결과는 첫째, 정책형성의 경로는, 1990년 저출산율의 1.57 쇼크라는 외부적 충격에 의한 중대국면에서 과거 일본 정부의 산아 조절 정책의 연속선이라는 우려에서 분리되고자 하는 역사적 유산과의 단절의 측면에서 경로의존적 특성을 보이는 것으로 해석되었다. 둘째, 정 책변화의 경로는, 제도 내부적인 새로운 정책이념의 등장, 저출산 문제의 심각성에 대한 거부권 없는 정치적 합의와 정책 결정 구조의 체계화, 새 로운 제도 내용의 추가적 누적이라는 제도적 맥락을 통해 경로진화와 제 도의 가겹의 특성을 보이는 것으로 해석되었다. 이러한 경로 과정을 고 찰하면서 일본 저출산 정책의 특성과 한계를 살펴보았다.

2023년 발표된 해양사고 통계에 따르면 해양 사고로 인한 인명피해는 소폭 감소하였지만, 해양 사고 발생 건수는 2021 ~ 2023년 까지 꾸준히 증가하고 있다. 이러한 해양사고의 예방 및 조치를 위해 정부 기관, 지자체 등에서는 안전 사업 추진 및 CCTV 관제 시스템을 구축하고 있다. 그 중 CCTV 관제 시스템은 야간 환경에서 가시거리 감소, 객체 식별의 어려움 등의 한계를 가지고 있다. 이러한 한계를 극복하기 위해 본 연구에서는 저조도 개선 알고리즘을 활용한 야간 해양 환경 개선에 관한 연구를 진행했다. 연구 진행간 저조도 개선 성 능과 실시간 안전 모니터링을 위한 영상 데이터의 처리에 초점을 맞췄다. 총 3가지의 저조도 개선 알고리즘과 2가지의 딥러닝 모델 경량 화 기법을 활용하여 최적의 실시간 저조도 개선 알고리즘을 선정하였다. 본 연구에서는 Bread 알고리즘에 Tensor RT 기법을 적용한 경우 에서 SSIM 0.7, FPS 100을 기록하며 저조도 개선 성능 및 실시간 데이터 처리에 가장 적합한 방안인 것을 입증하였다.

To determine the differences in food quality between fish fed a low fish meal diet containing black soldier fly (Hermetia illucens) instead of fish meal and those fed a general fish meal diet, we analyzed the approximate components, mineral content, amino acid composition, fatty acid composition, color, and texture of Flounder (Paralichthys olivaceus). The analysis of approximate components showed no difference between the two samples, except for moisture content. Mineral contents were measured in the order of K, P, Na, and Mg in both samples, with no difference except for phosphorus (P). A total of 16 amino acids were detected in both samples, with no significant differences in their composition. Additionally, 17 types of free amino acids were identified, with no significant differences between the two samples. The fatty acid composition consisted of 13 fatty acids, with palmitic acid, DHA, and oleic acid being the most prominent, although slight differences in content were observed. The color and texture also showed no differences between the two samples. Overall, there were no significant differences in chemical components or physical characteristics, so it was judged to be insignificant in terms of food science.

저층 건축물의 횡-비틀림 거동은 고차모드 효과를 증폭시킬 수 있으며, 내진성능평가 시 관련 기준은 고차모드 지배 구조물에 대해 비선형정적해석과 함께 선형동적해석을 추가로 수행하도록 규정하고 있다. 선형동적절차에는 상당한 안전계수가 적용되므로, 이는 과도한 내진보강설계로 이어질 수 있다. 이를 방지하기 위해 엔지니어들은 내진보강 시 고차모드 효과를 줄이기 위해 시행착오법을 사용해 왔다. 그러나 시행착오법에는 많은 시간과 노력이 소요되며, 결정된 보강안이 최적인지 확인하기 어렵다. 본 연구는 저층 건 축물의 수학적 모델을 수립하고 응답스펙트럼해석을 통해 고차모드 효과에 비틀림이 독립적으로 미치는 영향을 파악하였다. 이를 바탕으로 효율적인 내진보강 설계를 위해 활용될 수 있는 도표와 절차를 제시하였다. 제시된 절차를 통해 최소한의 내진보강으로 횡- 비틀림 거동하는 저층 건축물의 고차모드 효과를 효율적으로 감소시킬 수 있음을 확인하였다.

This study was conducted to establish a range of sodium reduction acceptable to consumers through collaboration between food and nutrition experts and franchise restaurants to reduce sodium in franchise restaurants. This study was conducted sequentially in 2018 using focus group interview and in-depth interview with experts, development of low-sodium pizza. Sodium content of low-sodium pizza was then analyzed along with preference evaluation of low-sodium pizza. Results of expert interviews showed that gradual sodium reduction was desirable. Sodium-reduced pizzas were manufactured using sauces and toppings that gradually reduced refined salt and soy sauce. Results of physicochemical analysis showed that sodium contents of pizzas were reduced by 5.3%, 7.9%, and 12.7% in the experimental groups P1, P2, and P3, respectively, compared to the control group (487.43 mg/100g). As a result of evaluating the intensity of pizza taste, saltiness and greasiness were lower in sodium-reduced pizza group, while sweetness and spiciness were higher. The preference and willingness to recommend sodium-reduced pizza were the highest for pizza with a 12.7% reduction. A 7-12% reduction in sodium in currently commercially available pizzas had no effect on taste preference. It is viewed positively by consumers. Thus, such reduction can be applied at a realistic level in franchise restaurants.

To prevent and improve various metabolic-related diseases caused by modern high-energy eating habits, alternative meats using mushroom materials are being researched. In this study, high-moisture (HMMA) and low-moisture meat analog (LMMA) were prepared using Pleurotus ostreatus fruiting body (oyster mushroom) powder and isolated soy protein as the raw materials in a co-rotating twin-screw extruder. Textural characteristics tended to decrease as the oyster mushroom content increased. HMMA exhibited a fibrous structure similar to that of chicken, whereas LMMA did not show a characteristic fibrous structure. The water absorption capacity of substitute meat decreased with increasing mushroom powder content. Radical scavenging activity, a measure of antioxidant activity, increased with increasing mushroom content in the substitute meat because of the influence of antioxidant components such as polyphenols in mushrooms. In terms of the prepared substitute meat's color, it was less vibrant and lacked intensity, which is thought to make it less appealing to customers. To address this issue, more ingredients need to be investigated.

Purpose: This study aimed to evaluate the effectiveness of low-fidelity simulation and actual human practice on the learning outcomes of a peripheral intravenous injection program for nursing students. Methods: Seventy-two third-year nursing students from a university in Seoul were included and divided into two groups; 38 and 34 in the low-fidelity simulation and human practice groups, respectively. The program was conducted from June 19–20, 2024. Data were analyzed using frequency, percentage, mean, standard deviation, χ²-test, independent t-test, and ANCOVA. Results: Both groups showed significant improvements in venipuncture performance, communication skills, empathy, academic performance, and self-efficacy. However, there were no statistically significant differences in these outcomes between both groups. Additionally, post-program learning satisfaction was similarly high in both groups. Conclusion: Low-fidelity simulation is as effective as actual human practice in achieving comparable learning outcomes in a peripheral intravenous injection program for nursing students. With appropriate instructional design, low-fidelity simulation can be a viable alternative to human practice, providing flexibility and accessibility in nursing education. This study underscores the importance of incorporating additional educational modules that enhance emotional and social skills, such as communication and empathy, tailored to the characteristics of individual learners.

This study aimed to evaluate the performance criteria of low-noise asphalt pavements under laboratory conditions. Laboratory tests were performed on eight porous and three non-porous asphalt mixtures. Draindown, Cantabro, tensile strength ratio (TSR), and dynamic stability tests were conducted to evaluate durability. The functionality was assessed using sound-absorption and indoorpermeability- coefficient tests. The laboratory results showed that all mixtures satisfied the quality standards for the draindown and TSR tests. In the dynamic stability test, all the mixtures demonstrated adequate rutting resistance. For porous mixtures, the Cantabro test results indicated sufficient shatter resistance and the indoor-permeability-coefficient test confirmed proper drainage performance. All mixtures exhibited satisfactory sound absorption, with the porous mixtures exhibiting slightly better sound absorption than the non-porous mixtures. Both porous and non-porous mixtures are durable and functional and are used in Korea. Future field tests are required to evaluate the noise reduction performance under different conditions and to compare the in-situ performance results with those from laboratory tests.

In this study, ester co-solvents and fluoroethylene carbonate (FEC) were used as low-temperature electrolyte additives to improve the formation of the solid electrolyte interface (SEI) on graphite anodes in lithium-ion batteries (LIBs). Four ester co-solvents, namely methyl acetate (MA), ethyl acetate, methyl propionate, and ethyl propionate, were mixed with 1.0 M LiPF6 ethylene carbonate:diethyl carbonate:dimethyl carbonate (1:1:1 by vol%) as the base electrolyte (BE). Different concentrations were used to compare the electrochemical performance of the LiCoO2/ graphite full cells. Among various ester co-solvents, the cell employing BE mixed with 30 vol% MA (BE/MA30) achieved the highest discharge capacity at − 20 °C. In contrast, mixing esters with low-molecular-weight degraded the cell performance owing to the unstable SEI formation on the graphite anodes. Therefore, FEC was added to BE/MA30 (BE/MA30-FEC5) to form a stable SEI layer on the graphite anode surface. The LiCoO2/ graphite cell using BE/MA30-FEC5 exhibited an excellent capacity of 127.3 mAh g− 1 at − 20 °C with a capacity retention of 80.6% after 100 cycles owing to the synergistic effect of MA and formation of a stable and uniform inorganic SEI layer by FEC decomposition reaction. The low-temperature electrolyte designed in this study may provide new guidelines for resolving low-temperature issues related to LIBs, graphite anodes, and SEI layers.

This paper studied a new shape unit model based on Gibson and Ashby's theory. As a result of theoretical research, the relative density equation is correlated with relative elasticity, and through this study, the theoretical relationship between the relative elasticity equation was defined. The relative elasticity equation was defined based on the model for which the analysis was performed. According to the analysis results, the diameter of the model was set to 3 mm, and the maximum stress values were confirmed by reflecting the same boundary conditions. The maximum stress for each model is 5668.9MPa for Type 1, 5136.7MPa for Type 2, 5642MPa for Type 3, and 6032.9MPa for Type 4 when the truss diameter is 3mm. The relative elasticity equation was defined based on this condition. In the future, compression analysis will have to be performed in the same way, reflecting the diameter of the truss at 5 mm and 7 mm, to find and define the coefficients of the relative elasticity equation, and verification through experiments will have to be carried out based on the theoretical equation. In addition, in order to be applied in each field, proof through prototype production and installation must be carried out.

The performance of various types of silencers used to reduce the micropressure waves radiated from ventilation holes and inclined shafts, which are being studied as measures to reduce micropressure waves in railway tunnels, was evaluated to find an effective silencer. In order to find the optimal silencer, the magnitude and frequency characteristics of the pressure waves emitted from the inclined shaft were analyzed to find an excellent silencer. The evaluation showed that the model with a porous cylinder and a small diameter outer tube was the simplest but performed the best.