In this study, when manufacturing a rectangular plate with a pinhole, the following conclusions were obtained as a result of analyzing the shape characteristics of the unit cell that fills the interior of the plate and the effect of changes in the size of the pinhole on the stress concentration coefficient. 1. The stress value generated in the case of the completely empty model was 13.9 MPa, which is an 18.8% increase in stress compared to the stress value 11.7 MPa generated in the fully filled model. However, since the weight of the empty model is 43.6% lower than that of the filled model, it is believed to be very advantageous in terms of cost. 2. The stress concentration coefficient value is lowest for the solid model and highest for the hollow model at the same d/H value. In other words, you can see that the values are changing within the boxes of the solid model and hollow model. However, the grid matching model is closest to the solid model and the filling rate is as low as 33.4-9.1%, showing the most stable strength when filling empty space.

Wearable electronics have been the focus of considerable interest in various fields, such as human-machine interfaces, soft robotics, and medical treatments, due to their flexibility, stretchability, and light weight. To address the shortcomings of existing metal thin film-based wearable devices, stretchable conductive polymers have been developed. In particular, double networking hydrogels are being actively studied as a polymer with a three-dimensional stereoscopic structure that can be patterned. Nonetheless, they have shortcomings such as poor electrical properties and cumbersome manufacturing processes, making it difficult to apply them in electronic devices. Herein, we report 3D-printed stretchable electrodes enabled by a titanium/polyacrylamide-alginate-based hydrogel nanocomposite. This research suggests the strategy for resolving the challenges of high costs and complex fabrication processes associated with stretchable electrode, providing a solution to accelerate the commercialization of wearable electronic devices.

This study focused on optimizing the digital light processing (DLP) 3D printing process for high-precision ceramic components using alumina-based slurries. Key challenges, such as cracking during debinding and precision loss due to slurry sedimentation, were addressed by evaluating the exposure time and the nano-to-micro alumina powder ratios. The optimal conditions—exposure time of 15 seconds and a 1:9 mixing ratio—minimized cracking, improved gas flow during debinding, and increased structural precision. Microchannels with diameters above 1.2 mm were successfully fabricated, but channels below 0.8 mm faced challenges due to slurry accumulation and over-curing. These results establish a reliable process for fabricating complex ceramic components with improved precision and structural stability. The findings have significant potential for applications in high-value industries, including aerospace, energy, and healthcare, by providing a foundation for the efficient and accurate production of advanced ceramic structures.

본 연구는 꼬막 패각 잔골재와 PP 폐어망 섬유를 혼입한 자원순환 콘크리트의 역학적 성능과 계면 변화 영역에서의 미세구조 특성 을 분석하였다. 패각 잔골재와 폐어망 섬유를 적절한 방법으로 전처리하고 자원화를 고려하여 3D 프린팅 콘크리트 배합을 선정해 콘 크리트 시편을 제작하였다. 제작된 시편은 KS L ISO 679 규정에 따라 압축강도와 휨강도를 측정하였고, BSE 모드를 이용한 SEM 이 미지 촬영을 통해 미세구조를 분석하였다. SEM 이미지는 히스토그램 및 형상 기반 상 분리 방법, 그리고 계면 변화 영역의 픽셀값 차 이를 활용하여 이미지를 분리하고 미세구조를 분석하였다. 역학적 성능을 확인하기 위해 PP 섬유를 0.0%, 0.5%, 1.0vol.% 혼입한 시 편의 압축강도와 휨강도를 측정한 결과, PP 섬유 0.5vol.% 혼입 시 섬유 브릿징 효과로 인해 가장 높은 압축 및 휨강도가 나타났다. SEM 이미지 분석 결과, 일반 잔골재와 바인더 계면보다 패각 잔골재와 바인더 계면에서 더 큰 직경의 공극이 관찰되었으며, PP 섬유 와 바인더 계면에서는 상대적으로 작은 공극이 형성됨을 확인하였다. 이를 바탕으로 미세구조 분석 결과와 역학적 성능 간의 상관관 계를 규명하였다.

This study analyzes the visual image effects regarding the design changes of sleeves and shoulders on plus-size women in their 20s and 30s to propose ideas for plus-size women’s clothing production and design. Based on a plus-size women’s basic raglan sleeve shirt, six types of raglan sleeve shirts with various design elements were developed using a 3D virtual imaging program to analyze the visual image effect of each pattern’s features. The results showed that the A-shaped sleeve silhouette, exemplified by Pattern A2, makes the upper body look longer and slimmer as a whole. It also conveyed a sense of refinement and attractiveness, displaying positive effects regarding body shape and aesthetic perception. Meanwhile, O-shaped silhouettes, such as Pattern B1 and Pattern B2, showed positive effects regarding comfort and mobility, while Y-shaped silhouettes, such as Pattern C1 and Pattern C2, created a visually confident appearance. Furthermore, the research examined the effects of static images and dynamic videos on evaluation outcomes. The results showed that dynamic images enhanced immersion and vibrancy, thereby increasing focus on the apparel evaluated. The results of the visual image evaluation can be used as a basis for designing not only raglan sleeves but also overall sleeve shapes.

Women in their 50s undergo significant changes to their bodies, including weight gain and rapid increases in body mass index (BMI) due to menopause. This study aimed to develop a basic bodice pattern suitable for women with a “square” body type, which is the most common type among Korean women in their 50s. We used a body shape avatar representative of square-body-type women in their 50s, provided by 6th Size Korea (KATS, 2010) as the model. This avatar was loaded into a virtual fitting program to evaluate the fit of the research pattern. The results of the study were as follows. Using the 3D virtual fitting program, the ideal bodice pattern was found to be close-fitting, based on an analysis of the body surface of women in their 50s with a square body type. This population’s characteristic body features included a rounded back, forward-protruding waist, forward-tilted neck, and shoulder tips angled toward the center-front. Because of the protruding abdomen, the bodice’s waist dart value was lower than average. The base bodice design for this body type was adapted from the research pattern of Jun and Jang (2024). Adjustments for this study included adding 0.5 cm to the center-back length and designing the profile line from the back neckline to the armpit wall. Further, the front bodice waist dart was omitted to accommodate the protruding abdomen. After two rounds of revisions, evaluations of the virtual fitting significantly improved, with scores increasing from 2.38 out of 5 to 4.82 out of 5.

This study aimed to develop a basic bodice suitable for the body shape of women in their 50s by using the CLO 3D virtual clothing program to create an avatar with the standard body presented in KATS (2022). A pattern was designed and produced using the CLO program, and the virtual fitting was evaluated. First, it was possible to confirm the slope (profile line) from the front center line to the point in front of the neck, the sagging shape of the breast, and the change in body shape due to the increase in bust circumference using the CLO program. Second, the change in body surface and body surface length according to movement was used to identify the profile line. The bust dart was very large. and the bust circumference showed the largest changes (5.05% in the 90° side and 1.5% of the breast width). Third, the total length reference line of the basic bodice was the back length (actual measurement). The total width reference line was the bust circumference/4+2cm and the breast width+0.5cm. The armhole depth reference line was the bust circumference/4–2. A profile line was created from the front neck circumference to the neck shoulder point to the breast point. Darts were formed on the back shoulder and back armhole lines. The allowances were 8 and 6cm for the bust and waist circumferences, respectively. All virtual fitting evaluation items improved significantly over two rounds (from 3.69/5 to 4.66/5 points).

This study explored the development direction of punk fashion through 3D digital fashion design by analyzing the expressive characteristics and inherent meanings of the punk fashion expressed in Vivienne Westwood’s creations. To this end, the concept underlying punk and its expressive characteristics were examined, and the eco-friendly expressive attributes of punk fashion were scrutinized through photos of Vivienne Westwood’s collections. The analysis focused on 10 seasonal collections showcased over the past five years, from the designer’s 2018 S/S to 2022 F/W collections. The results revealed that Westwood’s punk expression was characterized by traditionality, eco-friendliness, playfulness, resistance, and deconstruction. Traditionality appeared in the form of a harmonious redesign of classics to create new works, while eco-friendliness was manifested through the use of slogans and eco-friendly materials and methods. Playfulness conveyed positive messages through comedic situations or characters, and resistance emerged as a means of delivering messages for improving social issues. Finally, the deconstruction of punk was reflected as resistance, boldly destroying fashion structures to express dissatisfaction with society. Punk design in fashion is one of the avenues in which designers effectively express the messages that they want to communicate to society. This study is significant, as it provides foundational data for exploring punk characteristic design strategies to be used in future fashion. The scope of application for 3D virtual clothing programs is expected to expand in the fashion industry, and continuous research on digital fashion design is anticipated.

3D printing using ceramic powder to produce precision ceramic parts has been studied with various additive manufacturing methods. This study analyzed problems occurring in alumina additive manufacturing that uses digital light processing (DLP) as well as methods to address such problems. For efficient analysis, we have classified alumina additive manufacturing into three types according to the driving method of the build platform - lifting type (LT), tilting type (TT) of the vat, and blade movement type (BT). LT had a problem with detachment and cracking of the alumina green body. However, this could be prevented by carefully controlling the cure depth of the suspension slurry and the bonding force between layers and improving the material used for coating the vat. TT, which resulted in non-uniform alumina additive manufacturing, could be improved by modifying the bidirectionality of the axis and the fluidity of the highly viscous alumina suspension slurry. BT resulted in detachment of the specimen as well as non-uniform results, but this could be avoided by shortening the shifting distance of the alumina suspension when it is introduced to the build platform, and enabling effective spreading.

본 논문에서는 3D 프린팅 공정을 통해 제작된 단섬유 강화 복합소재 구조물의 기계적 거동을 효과적으로 예측하기 위한 AM 공정 연계 구조 해석 기법을 제안하였다. 복합소재 3D 프린터(Mark Two, Markforged)를 활용하여 다양한 노즐 경로를 갖는 인장 시편을 출력하였으며, 출력물에 대한 인장 시험을 진행하였다. 또한, 노즐 경로에 따른 부위별 이방 물성을 도출하기 위해 실험적 데이터를 기반으로 역공학 기법을 적용하였다. 제안된 AM 공정 연계 구조 해석 방안의 타당성을 검증하기 위해 실험 결과와의 비교/분석을 병 행하였으며, 부위별 이방 물성이 반영된 FE 모델을 바탕으로 AM 공정 연계 구조 해석을 수행함으로써 복합소재 3D 프린팅 출력물의 거동 양상을 정확하게 예측할 수 있음을 확인하였다.

PURPOSES : This study aimed to compare the object detection performance based on various analysis methods using point-cloud data collected from LiDAR sensors with the goal of contributing to safer road environments. The findings of this study provide essential information that enables automated vehicles to accurately perceive their surroundings and effectively avoid potential hazards. Furthermore, they serve as a foundation for LiDAR sensor application to traffic monitoring, thereby enabling the collection and analysis of real-time traffic data in road environments. METHODS : Object detection was performed using models based on different point-cloud processing methods using the KITTI dataset, which consists of real-world driving environment data. The models included PointPillars for the voxel-based approach, PartA2-Net for the point-based approach, and PV-RCNN for the point+voxel-based approach. The performance of each model was compared using the mean average precision (mAP) metric. RESULTS : While all models exhibited a strong performance, PV-RCNN achieved the highest performance across easy, moderate, and hard difficulty levels. PV-RCNN outperformed the other models in bounding box (Bbox), bird’s eye view (BEV), and 3D object detection tasks. These results highlight PV-RCNN's ability to maintain a high performance across diverse driving environments by combining the efficiency of the voxel-based method with the precision of the point-based method. These findings provide foundational insights not only for automated vehicles but also for traffic detection, enabling the accurate detection of various objects in complex road environments. In urban settings, models such as PV-RCNN may be more suitable, whereas in situations requiring real-time processing efficiency, the voxelbased PointPillars model could be advantageous. These findings offer important insights into the model that is best suited for specific scenarios. CONCLUSIONS : The findings of this study aid enhance the safety and reliability of automated driving systems by enabling vehicles to perceive their surroundings accurately and avoid potential hazards at an early stage. Furthermore, the use of LiDAR sensors for traffic monitoring is expected to optimize traffic flow by collecting and analyzing real-time traffic data from road environments.

목적 : 본 문헌 고찰은 임상 전문가가 임상환경에서 3D 프린팅 기술을 활용한 보조도구를 적용하거나 관련 연구를 수행할 때 참고할 수 있는 기초 자료를 제공하는 것을 목적으로 한다. 연구방법 : 국내･외의 전자 데이터베이스 KCI, RISS, PubMed, Scopus와 Web of Science를 사용하여 문헌을 검색하였 다. 검색된 문헌은 문헌 선정 과정에 따라 연구자 2인의 검토를 거쳤으며, 최종 16개의 논문이 선정되었다. 선정된 논문 은 출판연도 및 근거 수준, 저자의 전공 분야, 연구대상자의 일반적 특성, 보조도구의 종류 및 활동 영역, 주요 종속변인 및 평가도구에 대하여 분석하였다. 결과 : 16개의 논문을 분석하여 동향을 살펴본 결과 6편의 논문이 2024년도에 출판되었다. 연구의 근거 수준을 살펴본 결 과, 10편의 논문이 Level 5인 사례연구로 나타났다. 저자의 전공 분야를 살펴본 결과, 보건의료학에 포함되는 전공이 34 회로 나타나 가장 많았으며 그 중에는 작업치료학 전공이 8회로 가장 많았다. 지체장애인을 대상으로 한 연구가 11편으로 가장 많았으며, 지체장애인 중에는 척수손상 장애인을 대상으로 한 연구가 7편으로 가장 많았다. 보조도구를 활동을 중심 으로 분석하였을 때, 식사, 정보접근, 쓰기 활동을 위한 보조도구가 각 6편에서 나타나 가장 많았으며, 보조도구의 종류 는 홀더, 커프형 홀더, 스플린트형 홀더, 기타 보조도구로 구분되었다. 종속변인 및 평가도구에는 보조도구의 만족도를 Quebec User Evaluation of Satisfaction with Assistive Technology(QUEST 2.0)를 이용하여 평가한 문헌이 9편으 로 가장 많았다. 결론 : 본 연구를 통해 3D 프린팅을 활용하여 제작된 보조도구 연구의 출판 연도 및 근거 수준, 저자의 전공 분야, 연구대 상자의 일반적 특성, 보조도구의 종류 및 활동 영역, 주요 종속변인 및 평가도구에 대한 분석을 수행하여 향후 연구에 대 한 방향성을 제시하고자 하였다. 본 연구 결과를 바탕으로 작업치료학을 포함한 보건의료학 분야에서 보다 높은 근거수준 의 연구가 이루어 질 것으로 기대된다.

This study investigated the optimal process conditions and mechanical properties of Cu-10Sn alloys produced by the powder bed fusion (PBF) method. The optimal PBF conditions were explored by producing samples with various laser scanning speeds and laser power. It was found that under optimized conditions, samples with a density close to the theoretical density could be fabricated using PBF without any serious defects. The microstructure and mechanical properties of samples produced under optimized conditions were investigated and compared with a commercial alloy produced by the conventional method. The hardness, maximum tensile strength, and elongation of the samples were significantly higher than those of the commercially available cast alloy with the same chemical composition. Based on these results, it is expected to be possible to use the PBF technique to manufacture Cu-10Sn products with complex 3D shapes that could not be made using the conventional manufacturing method.

국내에서는 고속도로에는 콘크리트 포장을 적용하고 있지만 도심지에서는 콘크리트의 양생기간으로 인해 장기간 교통차단이 필요없 는 아스팔트 포장을 주로 적용하고 있다. 그러나 아스팔트 포장은 공용수명이 길지 않아 잦은 유지보수 작업으로 인해 사용자들의 불 편을 초래하고 있다. 본 연구에서는 현장타설 콘크리트 포장 공법을 적용하더라도 즉시 통행이 가능한 포장 임시보호판 개발을 위하 여 임시보호판의 하부 지지보 설치 간격 최적화를 목적으로 3차원 유한요소해석 프로그램을 이용하여 차륜 하중에 대한 응력분포를 분석하였다. 해석에 사용된 임시보호판은 길이 6m, 폭 3m, 두께 0.3m의 콘크리트 슬래브로 구성하였으며, 임시보호판의 하부 지지보 간격을 0.5m, 1m, 1.5m, 3m, 6m로 구성하였다. 하중 조건은 중차량인 버스를 고려하여 타이어 접지 면적당 33,540N의 분포하중을 지지 보 사이에 적용하여 분석하였다. 해석 결과, 하부 지지보 사이의 간격이 좁아질수록 응력이 감소하는 것을 확인하였다.

국내에는 지형적인 조건 또는 그 외의 여러 제약에 따라 줄눈 콘크리트 포장(JCP)을 시공하는 경우가 많았다. JCP는 시공 이후 양생 제로 도포함에도 불구하고 시간이 지남에 따라 부등건조수축이 나타나, 운전자의 승차감과 안정성을 악화시킨다. 이를 해결하기 위해 포장설계 지침을 지속적으로 개정하고 있지만, 부등건조수축으로 인한 민원이 계속 발생하고 있는 실정이다. 본 연구에서는 JCP의 부등건조수축량에 영향을 줄 수 있는 변수를 설정하여 변수에 따른 거동 차이를 보고자 하였다. 3D 유한요소해 석 프로그램 ABAQUS를 이용하여 유한요소법을 통한 해석을 진행하였고, 모델링은 2차로 6 슬래브를 모형화하였다. JCP의 부등건조 수축량에 영향을 주는 슬래브 깊이별 온도변화가 포장설계에 따라 어떻게 변화하는지 고려하기 위하여, 그에 대한 변수로 하부층 종 류의 영향, 슬래브 두께의 영향, 주행차로 다웰바 추가 설치 유무의 영향, 줄눈 간격의 영향을 설정하였다. 기본적인 모델의 유한요소해석 부등건조수축량 결과와 위에서 설정한 변수를 적용하여 만든 모델에 대한 유한요소해석 부등건조수축 량 결과를 각각 도출하였고, 기본 모델 결과와 변수를 적용한 모델 결과를 비교하여 각각의 인자가 어느 정도의 영향을 미치는지 확 인해 보았다. 영향이 큰 인자들을 선별하여 복합적인 변수에 대한 영향을 보고자 하였고, 복합 변수를 적용한 모델의 유한요소해석 부등건조수축 량 결과와 기본 모델의 유항요소해석 부등건조수축량 결과를 비교하여 그 차이가 어느 정도인지 확인하였다. 이에 따라 앞으로 JCP구 간 부등건조수축에 대한 해결을 위해 중점을 두어야 할 인자를 파악할 수 있었으며, 결과를 현장에 적절하게 적용한다면 도로 주행성 과 안전성을 개선할 수 있을 것으로 판단된다. 유한요소해석 결과에 대한 신뢰도를 부여하기 위해 현장 데이터와도 비교 분석하였고, 계절에 따라 약간의 차이는 있었으나, 평균값 과는 유사하여 본 연구의 구조해석 모형이 다양한 조건에 따른 연직변위 발생함에 있어 비교하는데 유용하다고 판단하였다.