The International Maritime Organization (IMO) is promoting the transition to eco-friendly fuels such as hydrogen and ammonia, with the goal of achieving net-zero greenhouse gas emissions in the shipping sector by 2050. Hydrogen does not emit greenhouse gases, but it must be stored at an extremely low temperature of -253°C when stored as a liquid. 316L stainless steel is mainly used as a tank material to store liquid hydrogen. FCAW (Flux Cored Arc Welding) is known for its excellent weldability with 316L stainless steel, and it is particularly suited for welding thick metals efficiently, making it an ideal choice for storage tank welding. Finite Element Method (FEM) analysis can simulate the thermal and mechanical deformations occurring during welding with high precision, allowing for accurate prediction of deformation patterns and the derivation of optimal welding conditions. This ensures the stability and quality of the structure while reducing costs. In this study, FCAW butt welding was performed on 316L stainless steel, followed by cross-sectional observation and deformation measurement of the weld area. Based on the cross-sectional observation, a 3D FE model was designed, and heat transfer analysis was conducted. Subsequently, thermo-mechanical analysis was carried out to predict welding deformation.

Magnesium alloys, among various non-ferrous metals, are utilized in diverse fields from the automotive industry to aerospace due to their light weight and excellent specific strength. In the previous Part I study, fiber laser BOP experiments were conducted to derive basic welding characteristics and appropriate bu竹 welding conditions. Subsequently, in the Part II experiment, butt welding was performed, and through tensile tests, hardness tests, and cross-sectional observations, it was found that at laser power of 2.0 kW and welding speed of 50 mm/s, 93% of the base metafs tensile strength and 63.4% of its elongation could be achieved. In this Part III experiment, the microstructures of the base metal and the center of the weld were observed in butt-welded specimens. Through this, laser power and welding speed, on the mechanical behavior and microstructure of magnesium alloys were analyzed

This study aims to establish the concept of fish welfare and develop guidelines for its implementation in South Korean aquaculture. As global awareness of animal welfare grows, scientific evidence shows that fish are sentient beings capable of experiencing pain and that stress has led to increased demand for welfare standards in aquaculture. International organizations like WOAH and the EU have set welfare standards for farmed fish, emphasizing their importance for health, productivity, and food safety. However, in South Korea, fish welfare is still an emerging concept with limited research. This study systematically defines fish welfare, assesses its feasibility in domestic aquaculture, and proposes guidelines tailored to local conditions. The findings highlight the need for gradual implementation, considering the unique biological and environmental factors in fish farming.

현재 도로포장 유지보수 과정으로부터 노화된 폐 아스팔트가 발생하며, 순환 아스팔트로서 재활용하기 위해 아스팔트 오일을 첨가제 등과 함께 혼합하여 노화된 아스팔트의 성상 회복 및 유동성을 개선하여 도로포 장 재료로 활용하고 있다. 또한 아스팔트 오일의 사용은 저온영역의 성능 개선에도 영향을 미쳐 개질아스팔트 제작에도 활용하고 있으며, 개질 아스팔트는 SBS(Styrene Butadiene Styrene), SBR(Styrene Butadiene Rubber)등 고무계열의 폴리머와 오일 등을 원 아스팔트에 혼합하여 아스팔트 바인더의 공용성을 향상시키는 기술로서 폴리머는 아스팔트의 고온 영역의 물성, 오일은 저온영역의 물성을 개선하는데 사용된다. 이 중 폴 리머에 관한 연구는 활발히 이루어지고 있는 반면 아스팔트에 사용하는 오일에 관한 연구는 상대적으로 연 구가 부족한 실정이다. 따라서 오일의 사용으로 인한 아스팔트의 물성 변화에 관한 실험적인 검토가 필요 하다고 판단된다.

온실가스 배출량을 최소화하기 위하여 가열 없이 생산이 가능한 상온 아스팔트 포장 공법도 2000년 초부터 개발되어 활용되고 있으 나, 기술적 한계로 인해 성능 확보가 어려워 대부분 기층용으로 활용중에 있다. 상온 아스팔트 혼합물은 유화아스팔트를 사용하는데 양생하는 동안 혼합물 내부에 있는 물이 증가됨에 따라 혼합물 내부의 높은 공극률이 발생하게 되어 포장의 성능을 확보하는데 한계 가 있다. 따라서 본 연구에서는 유화 아스팔트 내 아스팔트 고형분 함량을 증가시켜 물 함량을 최소화함으로서, 양생시간을 단축하고 낮은 공극률 확보를 통한 상온 아스팔트 혼합물의 성능의 변화를 평가하였다. 시험결과, 고형분 함량이 변화에 따라 공극률 및 간접인 장강도, 터프니스 물성이 변화가 나타났다. 하지만 고함량 고형분의 유화 아스팔트를 상온 아스팔트 혼합물에 적용하기 위해서는 최적 함수비 결정방식 및 양생방식 등에 대한 추가적인 연구가 필요한 것으로 나타났다.

본 연구의 목적은 외국인을 위한 한국어 쓰기 수업에 챗GPT를 활용할 경우 나타나는 학습자의 반응을 관찰하고 이를 있는 그대로 기술함으로 써 생성형 인공지능의 교육적 활용 가능성을 모색하는 데에 있다. 이를 위해 연구방법론으로 질적 사례연구를 선택하였으며 자료의 삼각화를 충 실히 이행하기 위하여 한 학기 동안 학습 결과물, 챗GPT와의 대화 내용, 수업 만족도 등을 수집하였다. 수집 자료를 분석한 결과 형태적 측면에 서는 문법적인 오류를 수정하고, 잘못된 표현을 바로잡는 데 챗GPT를 유용하게 활용하였으며 어휘적 측면에서는 모르는 단어나 구어체와 문어 체 간의 변환을 이해하는 데 도움을 받았고 내용적 측면에서는 주제문을 작성하고 논리적인 단락을 구성하는 데 도움을 받았다. 본 연구는 챗 GPT가 교수자와 학습자 간의 상호작용을 보완하여 학습자들의 학습 자 율성을 높일 수 있다는 가능성을 보여준다. 이는 전통적인 교수법의 한 계를 보완하며, 다양한 학습자들의 요구에 대응할 수 있는 새로운 교육 방법을 제시할 수 있다는 점에서 의의가 있다.

In this paper, we covered the basic design process of water-cooled cabinets and studied how to determine the target performance of heat exchanger design, which is essential in water-cooled cabinet design. A theoretical method was presented to set the target efficiency of the heat exchanger, and the pressure drop of air passing through the heat exchanger was predicted analytically. A cabinet-level thermal analysis was performed using the target efficiency and pressure drop data of the heat exchanger. The accuracy of the theoretical method was judged by comparing the theoretically predicted operating environment of the internal equipment with the analytically predicted operating environment of the internal equipment.

This study attempted to solve the problem that the current safety education contents of Korean fishing vessels are not consistent with the STCW-F Convention and do not properly reflect the actual operating environment of the fishing vessels. Despite the reinforced duty of safety education for fishing vessels after the Ferry Sewol accident, the problem has been pointed out that the effectiveness is still low due to merchant-oriented education contents and uniform education methods. Therefore, this study compared and analyzed laws related to safety education for fishing vessels and the STCW-F Convention, and derived improvement measures by collecting voices from the field through a survey of fishing vessels. As a result of the study, it was confirmed that the current fishing vessel safety education does not take into account the reality of fishing such as fishing vessel type, navigation distance, and ship output, and that the core curriculum required by STCW-F Convention is omitted. In addition, it was found that education content on major accident types that frequently occur along the coast was also insufficient. In order to improve this, this study proposes to re-establish the target of safety education for fishing vessels based on STCW-F Convention related to fishing vessels, and to prepare a segmented education system by reorganizing the training contents to suit reality. In addition, the need to clearly distinguish the education of merchant and fishing vessels through the revision of the Seafarers Act and the Ship Employees Act was suggested, and to establish a safety education system for fishing vessels that meets STCW-F Convention and domestic conditions.

세계적인 환경 규제로 인해 마그네슘 합금과 같은 경량 소재에 대한 수요가 증가하고 있으며, 마그네슘 합금 소재의 다양한 산업계 적용을 위한 용접 및 접합 방식에 대한 연구도 지속적으로 수행되고 있다. 앞선 Part I 연구에서는 마그네슘 합금에 대한 파이버 레이저 Bead on Plate(BOP) 실험을 수행하여 맞대기 용접 조건의 확보를 위한 기초 연구를 수행하였으며, 본 연구에서는 Part I의 기초 BOP 실험에서 도출된 적합한 레이저 출력과 용접 속도를 바탕으로 두께 3mm의 AZ31B 마그네슘 합금에 대해 맞대기 용접을 시행하였고, 인장시험 및 경도시험을 수행한 후 기계 물성 데이터를 분석하였다. 분석 결과 레이저 출력 2.0 kW, 50 mm/s (Heat input)의 조건에서 항복강도 151.5 MPa, 인장강도 224.1 Mpa으로 우수한 인장, 항복강도를 얻을 수 있었다.

글로벌화 시대에 소수민족 주제에 관련된 문화 작품들이 더욱 관객들 의 공감을 일으키면서 서사 방식은 매우 중요해졌다. 본 연구는 픽사 애 니메이션 영화 <메이의 새빨간 비밀> 속 주인공 메이의 청춘 서사를 탐 구하고 심리적 욕구를 중심으로 주인공의 성장 과정을 분석하여 심리적 욕구의 변화가 중국계 캐나다 청소년인 메이의 정체성 발전에 어떤 영향 을 미치는지 연구하는 것을 목적으로 한다. 본 연구는 사례를 분석하기 위해 기본심리욕구이론(BPNT)을 연구방법으로 삼았다. 애니메이션 속 주 인공 메이는 청소년기에 동서양 문화를 배경으로 한 자율성, 관계성, 유 능성이라는 세 가지 기본 심리적 욕구를 형성하여 중국계 캐나다 청소년 고유의 통합적인 정체성을 갖게 된다. 이 애니메이션은 중국계 청소년의 정체성 발달에 대한 건전한 사고를 보여주어 많은 관객에게 공감을 샀었 다. 본 연구는 중국계 청소년 정체성 발달과 관련된 문화 작품을 분석하 여 관련 작품의 창작에 기여하고자 한다. 본 연구는 <메이의 새빨간 비 밀>이 서구 대중문화의 전통적인 동서양 문화 가치관 대립 모델을 깨고 소 수민족 문화에 대한 주류 문화의 고정관념을 없애는 데 노력했다고 본다.

This study attempted to experimentally confirm the change in damping force for a prototype self-leveling damper with a pump rod and a leveling port applied with a new spiral flow path for small and medium-sized electric SUVs. The faster the excitation speed of the piston rod, the higher the damping force during compression and rebound and it can be seen that the graph shape appears in a similar pattern. Based on this, it can be used as basic data for additional characteristic tests such as temperature, sliding resistance, and operating sound test, etc.

Titanium constitutes approximately 60% of the weight of steel and exhibits strength comparable to steel's but with a higher strength-to-weight ratio. Titanium alloys possess excellent corrosion resistance due to a thin oxide layer at room temperature; however, their reactivity increases above 600°C, leading to oxidation and nitridation. Welding titanium alloys presents challenges such as porosity issues. Laser welding minimizes the heat-affected zone (HAZ) by emitting high output in a localized area for a short duration. This process forms a narrow and deep HAZ, reducing the deterioration of mechanical properties and decreasing the contact area with oxygen. In this study, fiber laser welding was conducted on 8.0mm thick Ti-6Al-4V alloy using the Bead On Plate (BOP) technique. A total of 25 welding conditions were experimented with to observe bead shapes. The results demonstrated successful penetration within the 0.792mm to 8.000mm range. It was concluded that this experimental approach can predict diverse welding conditions for Ti-6Al-4V alloys of various thicknesses.

Research into lightweighting to improve vehicle fuel efficiency and reduce exhaust emissions continues as environmental regulations become increasingly stringent. Magnesium alloys, chosen for their lightweight properties, are more than 35% lighter than aluminum alloys and also exhibit excellent mechanical characteristics. While magnesium alloys are commonly utilized in arc welding processes like GTAW and GMAW, they pose challenges such as high residual stresses and welding defects. Laser welding, on the other hand, offers the advantage of precise heat input, enabling deep and high-quality welds while minimizing welding distortion. In this study, fiber laser welding was employed to weld a 4.0mm thick AZ31B-H24 using the Bead on Plate technique. A total of 10 different welding conditions were tested with fiber laser welding, and the cross-sections of the weld beads were examined. Weld bead shapes were measured based on five parameters. The results allowed for an evaluation of the weldability of AZ31B-H24 using fiber laser welding.

PURPOSES : Derive a road pavement design method using Geocells, aim to derive a road pavement design and construction method suitable for the characteristics of the Bangladesh region METHODS : To assess long-term performance during road construction in Southeast Asia using Geocells, field tests and numerical analysis are conducted to verify stability. RESULTS : A total of 12 displacement measurements were conducted during the field tests, confirming an average load of 15.75 kN and an average displacement of 0.542mm. Inverse analysis was performed to obtain the properties of Geocell combined with compacted soil. The numerical analysis results confirmed that the insertion of Geocell provides better stability compared to the case with only compacted soil. CONCLUSIONS : Based on field tests and numerical analysis, a road design plan suitable for the Southeast Asian environment was proposed. A preliminary test section was selected in the Comilla region of Bangladesh, and test construction has been completed. Subsequent evaluations of the structural performance by soil layer in the test construction area will be conducted to develop a Geocell road pavement method, taking into consideration the characteristics of the Bangladesh region.