In apartment buildings in Korea, irregular walls, such as T-, L-, and U-shaped walls, are commonly used. However, in practical design, the geometric irregularities of walls are often neglected when determining the length of the lateral confinement region. Further, although earthquake loads apply from various directions, the lateral confinement region is typically determined for the in-plane direction of the web. Thus, using finite element analysis, this study investigated the structural performance of irregular walls subjected to various loading directions. As the design parameters, wall shape, cross-sectional aspect ratio, and loading direction were addressed. According to the parametric analysis results, as the length of flange in tension increased, the lateral confinement region should be evaluated with consideration of the geometric irregularity. Further, for the L- and U-shaped walls, it is recommended to evaluate the lateral confinement region for various loading directions. Based on these results, a design method to determine the lateral confinement region of irregular walls was suggested.

본 연구는 고등학교 지구과학교육에서 ChatGPT가 제공하는 과학적 응답의 타당성을 분석하고, 그 한계 및 향 후 과제 탐색을 목적으로 한다. 이를 위해 15명의 지구과학 예비교사가 2015 개정 교육과정을 기반으로 지구과학 I과 지구과학 II의 내용을 바탕으로 총 600개의 질문-이유-확신도(Q-R-C) 프롬프트 구조의 문답을 생성하였다. 본 연구는 문서 분석(document analysis) 방법을 적용하여 ChatGPT의 응답을 과학적 타당성, 설명적 명확성, 교육적 적합성의 기 준으로 독립적으로 평가하였다. 분석 결과, ChatGPT의 응답 중 85% (N=510)는 과학적으로 타당했으며, 81.2% (N=487)는 설명적 명확성을 충족하였고, 78.7% (N=472)는 지구과학 교육과정에 부합하는 내용을 포함하고 있는 것으 로 나타났다. 반면, ChatGPT 응답의 한계로는 개념적 일관성 부족, 추론 기반 응답의 오류 가능성, 응답 수준의 불균형, 지역별 특이성 미반영이 확인되었다. 이는 ChatGPT가 개념 학습을 지원하는 교육적 도구로 활용될 가능성을 시사하지 만, 향후 효과적인 교수 전략을 통해 교사의 지도와 비판적 사고를 촉진하는 과정이 필수적임을 보여준다. 본 연구는 생성형 AI (Gen AI) 기반 도구가 지구과학교육에서 효과적으로 적용될 수 있는 방안을 탐색하며, 향후 교수·학습 설계 에서 고려해야 할 시사점을 제공한다.

본 연구에서는 단계적인 수온 상승에 따른 조피볼락 Sebastes schlegli의 연속적인 행동 패턴을 관찰하고, 혈액성상 변화를 분석하여 고수온에 노출된 생물의 아치사 행동 반응, 내성 한계 및 임계 수온을 규명하였다. 수온에 대한 조피볼락의 생태-생리 반응은 노출 수온 및 시간에 따라 유의한 차이를 보였다(p<0.05). 본 종은 25.0~30.0℃ 수온 범위에서 비정상적인 행동을 보였으며, 내성 한계에 도달하였다. 고수온에 대한 혈장 내 cortisol과 SOD 농도 변화를 고려할 때, 조피볼락은 체내 스트레스 증가로 인해 항상성 유지 효소 분비가 방해되어 25.0℃ 이상의 수온에서 정상적인 대사 활동을 수행할 수 없었다. 결론적으로 조피볼락의 행동 및 대사 활동은 cortisol과 SOD 활성이 빠르게 변하는 25.0℃ 수온에서 교란되었으며, 30.0℃에서는 아치사 행동 반응이 관찰되었다. 이와 같은 결과는 고수온기 연안 정착성 어류의 패사 원인을 예측하는 자료로 활용 가치가 높은 것으로 판단된다.

이 연구는 생성형 인공지능(Gen AI) ChatGPT를 활용한 초등과학 모의수업에서 나타나는 실천적 특성 탐색을 목적으로 한다. 비수도권 소재 교육대학교 과학교육과의 예비교사 29명을 대상으로, 태양계와 별, 날씨와 우리 생활, 지 구와 달의 운동, 계절의 변화 등 지구와 우주 영역의 대단원을 중심으로 5주간 한 차시 과학 수업을 준비하였다. 자료 는 수업 지도안, 수업 자료, 활동지, ChatGPT 대화 로그, 모의수업 영상 및 음성녹음, 반구조화된 면담 등을 통해 수집 되었다. 자료 분석은 기술 통합 평가 틀(TIAR)을 수정하여 주제 중심 분석과 반복적 비교 분석을 통해 귀납적으로 진 행되었다. 연구 결과, ChatGPT는 초등과학 수업에서 교육과정과의 연계성, 교수학습 모형, 도구적 활용 측면에서 유의 미하게 작용할 수 있음을 보였다. 특히, ChatGPT는 학습 활동을 촉진하는 도구로 긍정적인 역할 수행의 가능성을 나타냈다. 그러나 ChatGPT 활용 시 정보의 신뢰성 문제, 명령어 입력 한계, 학생들의 Gen AI 의존성, 교사의 역량 요구 증가 등 도전 과제도 확인되었다. 이 연구는 ChatGPT가 과학교육에서 학습 촉진자로 유용하게 활용될 수 있음을 시사 하며, 효과적인 활용을 위해 교사의 비판적 사고와 기술적 역량 강화를 제언하였다.

Fishways, particularly installed at the estuary, have a purpose to encourage fluent migration for migratory fishes, as well as amphidromous and even freshwater species. Not choosing the laborious traditional method of using traps, we assessed the efficiency of the two fishways installed at the west and east barrage of the Nakdong River estuarine barrage respectively, by analyzing the videos recorded through automatic monitoring system. We randomly selected 30 videos monthly at each fishways and identified what kind of fishes were using the fishways and categorised their behaviour such as size, time and whether they passed the monitoring system or not. As a result, a total 8 families 14 species were recorded by monitoring system, with the most dominance of Erythroculter erythropterus (Relative Abundance: 59.5%), followed by Micropterus salmoides (R.A: 19.9%) and Mugil cephalus (R.A: 9.9%). The monitoring system can capture passing fishes during night but the number of appearances of fish species at each hour of a day indicated significant diurnal activities (p<0.05). When fishes pass the monitoring system, approximately 70% of them passed through the monitoring device, while 17% of them showed fallback movement. Our finding indicates that species-specific characteristics of each fish are well represented through video monitoring method. In order to maximise advantages of using video monitoring, it is necessary to consider the installation point properly so that the monitoring system does not interfere with the movement of fish. Also, the utilisation of AI technology in the future is also necessary.

이 연구의 목적은 Giorigi의 현상학적 연구 방법을 토대로 지구과학 예비교사들이 ChatGPT를 활용한 과학 수업 실행 경험을 탐색하는 것이다. ChatGPT를 활용한 지구과학 모의 수업을 경험한 예비교사 4명(남2, 여2)이 이 연구에 참여하였다. 연구 참여자들을 대상으로 두 차례 걸쳐 면담을 진행하였다. 면담은 통시적인 관점에서 개인적 경험에 대 해 생애사적 이해, 실제 경험, 의미에 대한 성찰 세 단계로 구분되었다. 지구과학 예비교사들이 ChatGPT를 활용한 수 업 실행 경험 분석 결과, ‘기술에 대한 불안에서 자신감으로 Gen AI 활용에 대한 인식 변화’와 ‘Gen AI의 과학 교수 학습적 한계와 도전적 접근’으로 구분하였다. 세부적으로 ‘교수학습 과정에서 수업 설계의 주제 선정 및 탐구 활동의 구체화’, ‘ChatGPT 수업 실행의 도구적 활용 및 과학적 탐구 활동 촉진’, ‘Gen AI의 정보 제공과 그 한계’, ‘교사의 교 수학습 개입의 필요성, 유의점 그리고 향후 과제’로 구체화하였다. 이 연구는 지구과학 예비교사들이 ChatGPT를 활용한 수업을 통해 Gen AI 도구의 교육적 활용과 교사 역량 개발에 대한 기초적인 자료를 제공하는 것으로써 향후 Gen AI 기반 지구과학 학습의 이론적 토대를 마련하는 데 도움이 될 것이라 기대한다.

본 연구는 합성 아질산염 대체 천연보존료로 개발하고자 천연물 유래 복합추출물(NP-NAP, NP-NAMR)의 성분 특성 과 소시지에의 적용 시 품질 특성을 규명하였다. NP-NAP 와 NP-NAMR 0.5-1.0% (w/v)는 90.1-100%의 ABTS 라디 칼 저해능과 10 mg/mL에서 각각 811 μM 및 770 μM trolox 상당의 FRAP 활성을 보였다. NP-NAP와 NP-NAMR은 S. aureus와 L. monocytogenes, E. coli 및 S. Typhimurium에 대 해 0.1% (w/v)에서 99.99-100%의 감소율을 보였고 C. perfringens에 대해 1%와 2% (w/v)에서 각각 89.0-91.4%와 84.7-100% 이상의 감소율을 보였다. 천연 복합추출물 첨가 소시지 시제품의 냉장 중 품질 특성에서 4주 차 pH (6.43- 6.57)와 NP-NAMR 첨가 시 높은 a 값(23.54% 및 28.81)을 확인하였다. Springiness와 cohesiveness는 NP-NAP 1%가 높 았으나 다른 모든 시험구는 양성 대조구와 유의적 차이가 없었다(P<0.05). 냉장 중 평균 MDA (0.87-1.183 μM)는 양 성 대조구(0.93-0.96 μM)와 유사하였으며(P<0.05) 총 증가 균수(log CFU)는 1% 첨가(1.10-1.32) 시 nitrite pickling salt (NPS) 0.08% (1.31)과 유사하였고 2% 첨가 시(0.17-0.49)는 commercial product from Spain (CPS) 1% (0.53)보다 적었 다. 종합적 기호도는 NP-NAMR 2% 제외한 모든 시험구는 통계적 유의차가 없었다. 이상의 결과, 과채 추출물 유래 NP-NAP와 NP-NAMR은 항산화, 항균 활성과 안정적인 적 색도와 함께 식약처 고시 소시지류의 기준 및 규격을 만족 하여 합성 아질산염과 시판 수입품을 대체하는, 유효한 소 재가 될 수 있을 것으로 사료된다.

The Indoor Air Quality Control Act aims to regulate indoor air quality (IAQ) to safeguard public health and promote a comfortable living environment. This law encompasses multi-use facilities, newly constructed residential complexes, and public transportation vehicles. The law also involves mandating air quality standards, conducting periodic measurements, and transparent public reporting of results. Over time, the Indoor Air Quality Control Act has expanded to enforce stricter controls on building materials and enhance radon mitigation measures. In doing so, it embodies the principles of the Environmental Policy Basic Act and is supported by other laws, policies, and systems related to air quality management. In line with these efforts, local governments have been implementing IAQ initiatives tailored to regional needs, including consulting services and financial support. However, challenges persist in harmonizing management across diverse facilities due to overlapping responsibilities among laws and government bodies. Future recommendations emphasize integrated strategies and enhanced inter-agency coordination to address these gaps effectively, ensuring healthier indoor environments for all stakeholders.

The purpose of this study is to experimentally analyze the seismic performance of a vertical irregular beam-column specimen reinforced with RBS (Replaceable Steel Brace System), a steel brace system. To evaluate the seismic performance of RBS, three specimens were manufactured and subjected to cycle loading tests. The stiffness ratio of beam-upper column of the non-retrofitted specimen was 1.2, and those of the two retrofitted specimens were 1.2 and 0.84. The stiffness ratio of the beam-lower column of all specimens was 0.36. And the stiffness ratio were used for variable. As a result of the experiment, the specimen retrofitted with RBS showed improved maximum load, effective stiffness and energy dissipation capacity compared to the non-retrofitted specimen with the same beam-upper column stiffness ratio. The specimen with 0.84 beam-upper column stiffness ratio showed improved performance compared to the specimen with 1.2 stiffness ratio.

As the use of shared kickboards rapidly increases, personal mobility (PM)-related accidents are frequently occurring. These accidents are mainly caused by careless behavior, which is typically indicated by neglecting to wear a helmet, speeding, signal violation, or illegal driving owing to incorrect driving methods. This type of user behavior increases the risk of accidents; for this reason, there is an urgent need to prepare effective measures for the safe use of shared kickboards. To reduce PM accidents, this study proposes a charging model that promotes the safe behavior of shared kickboard users. The core aim of this model is to persuade users to comply voluntarily with safety rules through incentives and penalties. Specifically, by providing a discount rate when wearing a helmet, the user is encouraged to wear a helmet, whereas in the event of an accident, a penalty is imposed to emphasize the disadvantages that occur when the safety rules are violated. This incentive structure is expected to contribute to the development of safer driving habits among shared-kickboard users. To verify the effectiveness of this charging model, simulations and user surveys were conducted in parallel. It was found that the user’s safety behavior improved, and the incidence of accidents decreased considerably. This confirmed that the proposed charging model not only reduced accidents but also naturally formed a safe driving culture for users. The shared key proposed in this study can benefit the operating company, and policymakers can contribute in the future by sharing key issues that are expected to play an important role in presentation and punishment, and provide a new paradigm for sharing key paradigms.

Recently, high-rise residential buildings in Korea have adopted slender shear walls with irregular section shapes, such as T-shape, H-shape, and C-shape. In the seismic design of the slender shear walls, the transverse reinforcement for lateral confinement should be provided in the boundary elements to increase deformation capacity and subsequent ductility. However, in practice, the irregularity of the shear walls is not adequately considered, and the lateral confinement region is calculated for the rectangular wall segments. This study investigated the proper design method for lateral confinement regions using finite element analysis. The lateral confinement region was considered in analysis for two cases: 1) as a typical rectangular wall segment and 2) as an irregular wall. When the irregularity of the walls was considered, the compression zone depth was increased because the vertical reinforcement in the flange was addressed. The effect of lateral confinement design methods on the structural performance of the walls was directly compared under various design parameters, including the length of the flange, concrete compressive strength, vertical rebar layout, axial load ratio, and loading direction. According to the results of the parametric analysis, the peak strength and deformation capacity could be significantly increased when the lateral confinement region was calculated based on irregularly shaped walls, regardless of the design parameters. In addition, the effective compression zone was located within the lateral confinement region. Thus, it is recommended that the lateral confinement region of T-shaped walls is calculated by addressing the irregularity of the walls.

국제해사기구(IMO)의 규제강화로 인한 선박탄소집약도지수(CII)를 충족시키기 위하여 최근 친환경 기술인 로터세일(Rotor sail) 기술도입이 부각되고 있다. 1924년 첫 로터세일 장착선박이 개발된 이래로 다양한 연구개발이 진행되어져 왔고 이미 해외기업에 의 해 상용화 되어져 있다. 이러한 기존 원통형 로터(Rotor)는 로터의 속도비(Spin ratio) 증가 시 일정구간 이후부터 공기역학적 효율(CL/CD) 이 감소하는 현상이 발생된다. 이 점을 해결하기 위하여 2019년 한 차례 선행 연구된 새로운 원뿔형 로터를 이해하고 조건을 재설정하 여 최적의 공기역학적 효율 조건을 연구하였다. 원통형 로터와 원뿔형 로터에 속도비와 로터상부지름(Rotor top diameter, d) 대 끝단플레 이트지름 (End plate diameter, De) 비로 변수를 적용한 12가지 조건을 연구하였다. 그 결과 원뿔형 로터에서만 로터의 속도비 증가에 따 른 공기역학적 효율은 일정하거나 약간 증가하는 현상이 나타났으며 끝단플레이트의 지름 비율이 4배인 특정 조건에서 명확히 확인 할 수 있었다.

PURPOSES : Recently, interest in radioactive accidents has increased due to domestic and international nuclear power plant accidents. In particular, local residents' concerns are increasing due to safety issues such as radioactive leaks at the Hanbit Nuclear Power Plant in South Korea. As Gwangju Metropolitan City is not included in the emergency planning area set by the Nuclear Safety and Security Commission, there are significant limitations to establishing disaster prevention measures for nuclear power plant accidents. Considering the Fukushima and Hanbit nuclear power plant accidents, the improvement of Gwangju Metropolitan City's radioactive leak accident response manual is urgently required. This study aimed to establish disaster prevention measures to respond to nuclear power plant accidents in Gwangju Metropolitan City in the event of a Hanbit Nuclear Power Plant accident and to improve resident protection measures by estimating the arrival time of radioactive materials and radiation dosage through a nuclear power plant accident simulation. Additionally, we aimed to supplement the on-site action manual for radioactive leaks at the Hanbit Nuclear Power Plant. METHODS : This study focused on establishing disaster prevention measures centered on Gwangju Metropolitan City in the event of a major accident such as a radioactive leak at the Hanbit Nuclear Power Plant. Simulations were conducted assuming a major accident such as a radioactive leak, measures to improve resident protection were established by calculating the arrival time of radioactive materials and radiation dosage in the Gwangju area in the event of a nuclear power plant accident, and on-site response action manuals were supplemented in response to a radioactive leak. RESULTS : This study considered the concerns of local residents due to the Fukushima nuclear power plant accident and the Hanbit nuclear power plant failure, conducted a simulation to derive the impact on Gwangju Metropolitan City, and examined the effectiveness of an on-site response manual for radioactive leaks to derive improvement measures. CONCLUSIONS : In the event of an accident at the Hanbit Nuclear Power Plant in Gwangju Metropolitan City, insufficient portions of the on-site response action manual should be supplemented, and close cooperation with local governments within the emergency planning area should be ensured to respond to radioactive disasters. Therefore, based on the revised on-site response action manual for radioactive leaks, close cooperation and a clear division of roles among local governments will enable effective resident protection measures to be implemented in the event of a radioactive disaster.

This study identifies the possibility of alignment discrepancies during mortar firing when using inactive fuzes, which make it impossible to visually observe impact points. To address this issue, we studied a quality assurance method for Sight Alignment after firing. To establish a baseline, we analyzed the pre-firing Sight Alignment and the impact group status during firing for 00 mortars and 000 shells. Based on this analysis, we derived the alignment position information range after firing for 36 mortars, distinguishing between 68% and 95% confidence interval. Finally, considering data characteristics, inspection time requirements, and non-conforming data, we selected the Sight Alignment range after firing based on the 95% confidence interval. This study is expected to contribute to the development of quality assurance methods for munitions by serving as an example of quality assurance in the mass production stage of mortars.

This study is to deal with a failure phenomenon that occurred during a vibration test on an Inertial Navigation System mounted on a self-propelled howitzer. Vibration occurs naturally due to the operation characteristics of self-propelled howitzers, The study describes a case of failure that occurred during the durability verification process. It explains the function and configuration of the INS(Inertial Navigation System) and describe how the failure occurred through understanding the phenomenon. Based on the occurrence phenomenon, an in-depth cause analysis was conducted and fundamental improvement measures were presented to prevent recurrence. It is expected that this study will aid as a reference for problem solving when similar failures occur in the future.

This study evaluates the potential of various coagulants to enhance the efficiency of total phosphorus removal facilities in a sewage treatment plant. After analyzing the existing water quality conditions of the sewage treatment plant, the coagulant of poly aluminium chloride was experimentally applied to measure its effectiveness. In this process, the use of poly aluminium chloride and polymers in various ratios was explored to identify the optimal combination of coagulants. The experimental results showed that the a coagulants combination demonstrated higher treatment efficiency compared to exclusive use of large amounts of poly aluminium chloride methods. Particularly, the appropriate combination of poly aluminium chloride and polymers played a significant role. The optimal coagulant combination derived from the experiments was applied in a micro flotation method of real sewage treatment plant to evaluate its effectiveness. This study presents a new methodology that can contribute to enhancing the efficiency of sewage treatment processes and reducing environmental pollution. This research is expected to make an important contribution to improving to phosphorus remove efficiency of similar wastewater treatment plant and reducing the ecological impact from using coagulants in the future.

In this paper, the cause of mortar baseplate breakage was analyzed by diving into cross-section, material, process, and design aspects. As a result of observing the fracture surface and non-fracture suface using optical equipment, it was possible to confirm changes in the shape of disconnected line and metal surface at a specific area. In addition, a number of linear defects due to overlap were found. Flow analysis was performed using the Deform program to verify changes during the production process. According to the result, a drop test was performed on each of the lap detection baseplate, undetection baseplate, and removed product to verify the presumptive cause of the rupture of the poplite.

There are two primary sludge drying methods such as the direct heating microwave method and the indirect heating steam one. In this study, the drying treatment facility at sewage treatment plant A applied both of these drying methods. The research aimed to investigate the optimal operation approach for the drying facility, considering the input sludge and the moisture content data after the drying process. Moisture content and removal rate data were executed at the research facility from January 2016 to December 2018. First, the microwave, a direct heating drying method, performed intensive drying only on the outer surface of the sludge by directly applying heat to the sludge using far infrared rays, so effective sludge drying was not achieved. On the other hand, the steam method of the indirect heating method used steam from a gas boiler to maximize the utilization of the heat transfer area and reduce energy of the dryer, resulting in an effective sludge drying efficiency. The sludge moisture content brought into the sludge drying facility was about 80%, but the moisture content of the sludge that went through the drying facility was less than 10% of the design standard. Therefore, the steam method of the indirect heating method is more effective than the microwave method of the previous direct heating method and is more effective for maintenance It has proven that it is an efficient method of operating construction facilities.