• 한국건설관리학회논문집
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• 제10권1호
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• pp.136-145
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• 2009

'지능형 굴삭시스템 개발'은 센서기술, 로봇기술들을 융합하여 토공 작업환경을 인식하고 작업 계획을 수립하며 굴삭기를 자동 조정하여 토공작업을 자동화 하는 것을 목표로 한다. 본 연구는 지능형 굴삭시스템 개발을 위한 요소기술로서, 광대역 3D 레이저 스캐너를 이용하여 실제 토공 작업환경을 가상의 3차원 공간으로 재현할 수 있는 수학적 모델을 만드는 것이다. 이 연구에서는 광대역 3D 레이저 스캐너를 구동하기 위한 사용자 소프트웨어 및 사용자 인터페이스를 개발하였으며, 3D 레이저 스캐너의 차량 탑재 및 스캐닝 작업의 최적화를 위하여 모바일 3D 이미징 시스템을 개발하였다. 또한 실제 토공 작업환경을 대상으로 스캐닝 실험을 실시하여 스캔 데이터를 획득하였고, 이를 기반으로 각 스캔 데이터들 간의 자동 정합 알고리즘을 설계하였다. 본 연구에서 개발된 시스템은 향후 지능형 굴삭 로봇의 완전 자동화 시스템의 구현을 위하여 널리 활용될 수 있을 것으로 기대된다.

• 한국의류학회지
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• 제30권1호
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• pp.157-166
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• 2006

The human body, which is composed of concave and convex curvatures, makes it difficult to transfer into 2D patterns directly from 3D data. In previous studies. Jeong, et al.(2004) suggested the block method was fester and easier when dealing with the triangular patches of male's upper dress form. Although the block method is useful to make a pattern, the information(area, length, etc.) from a 2D pattern would be different depending on the direction of the block method. As a result horizontal and diagonal block methods were suggested as optimal methods for 2D tight-fitting patterns. These block methods were closer to the original area of the 3D scan data than the vertical block method. The total area of the 2D pattern obtained by the horizontal and diagonal block methods showed little differences. In case of the horizontal and diagonal block methods, the total error of the 2D pattern area ranged from $0.01\%\~0.25\%$. In comparing the length of the 2D pattern with that of the 3D scan data, the obtained 2D pattern was $0.1\~0.2cm$ shorter than the 3D scan data, which was within the acceptable range of errors in making clothes. 3D space distribution images between the body surface and the experimental clothing were also measured and $3\%$ enlargement of the original pattern was verified as the adequate adjustment.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2022년도 봄 학술논문 발표대회
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• pp.188-189
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• 2022

With the development of nano-reinforcement technology, TiO₂ nanomaterials have received widespread attention as one of the additives without pozzolanic reaction, which can be used to improve the mechanical properties of cement-based materials. Meanwhile, with the development of additive manufacturing technology or known as 3D printing technology, its application in the construction field has also got noticed. Therefore, in this work, the effect of three sizes of TiO₂ on the compressive strength of hardened cement-based materials fabricated by binder jetting 3d printing was evaluated. According to the results, the TiO₂ particles with larger sizes can provide better reinforcement to the hardened cement due to its more significant filling effect.

• 한국CDE학회논문집
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• 제10권2호
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• pp.77-88
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• 2005

This paper introduces a project for the development of an F-125 machine using 3D PLM systems including 3D CAD, CAM, CAE, PDM, and DMU systems. Here, the F-125 machine is a formula racing car equipped with a 125cc motorcycle engine. A development process and computer-integrated environment was established using 3D PLM systems on the conceptual basis of concurrent and virtual engineering. A DMU model for a full vehicle was built using CATIA V.5 and used to check interference between parts and to simulate assembly process. This DMU-based approach enables to find and fix manufacturing problems in the early design stage. All development activities have been done by the graduate and undergraduate students of the automotive engineering department of Kookmin University. Through the project, the students could acquire knowledge about car development process and 3D PLM systems in automotive industry.

• 한국수정란이식학회지
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• 제31권3호
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• pp.169-177
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• 2016

There is a growing interest in the application of primary hepatocytes for treatment of liver diseases in humans and for drug development. Several studies have focused on long-term survival and di-differentiation blocking of primary hepatocytes in an in vitro culture system. Therefore, the present study also aimed to optimize an in vitro culture system using primary rat hepatocytes. Primary rat hepatocytes from 6-week-old male Crl:CD rats were isolated using a modified two-step collagenase perfusion. Healthy $3.5{\times}10^6$ primary rat hepatocytes were seeded into a 2 dimensional (2D) culture in a 25T culture flask coated with collagen type I or into a 3D culture in a 125-ml spinner flask for 7 days. Production of plasma protein (ALB and TF), apoptosis (BAX and BCL2), and CYP (CYP3A1) related genes were compared between the 2D and 3D culture systems. The 3D culture system had an advantage over the 2D system because of the relatively high expression of ALB and low expression of BAX in the 3D system. However, the level of CYP3A1 did not improve in the 3D culture with and without the presence of a dexamethasone inducer. Therefore, 3D culture has an advantage for albumin production and primary rat hepatocyte survivability, but a low expression of CYP3A1 indicated that primary rat hepatocytes require a high-density culture for stress reduction by continuous flow.

• Animal cells and systems
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• 제3권4호
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• pp.369-374
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• 1999

The life history and development of Tetrastichus sp. parasitizing fallwebworm pupa in Korea were studied. The mean lifetime fecundity was 94.7 with a maximum of 125, and the portion of female progeny averaged 90.3%. A male and a female lived for an average of 19.8${\pm}$4.5 and 21.7${\pm}$4.2 days, respectively. The duration of development for each stage was as follows: egg, 2 d; the 1st instar larva, 2${\pm}$1 d; the 2nd instar larva, 2${\pm}$1 d: the 3rd instar larva, 3${\pm}$1 d; the 4th instar larva, 6${\pm}$2 d; and pupa, 8${\pm}$2 d. Total developmental duration from hatching of the larva to adult emergence required 21.1${\pm}$3.7 d, and females took 1-2 days more than males in the incubator (28$^{\circ}C$, 70% RH, and 16:8 LD).

• 한국건축시공학회지
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• 제10권3호
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• pp.71-81
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• 2010

건설R&D 사업은 1994년에 12억원으로 시작하여 2007년에는 1,648억원을 투자하였다. 그동안 연구개발자는 연구성과 실적을 한국건설교통기술평가원에 제출하였고, 이를 기반으로 건설R&D성과 관리가 이루어져 왔다. 건설R&D사업 성과실적이 연구자의 주관적인 분석결과와 보고자료에 의존함으로써 건설R&D 성과의 객관성 및 신뢰성 확보가 어려웠다. 따라서 본 연구는 건설R&D 성과 중 개발기술의 현장적용 비용절감액 분석과 객관적이고 신뢰성있는 경제적 파급효과를 분석하고, 건설R&D의 현장적용 활성화 방안을 마련하였다.

• 한국의류학회지
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• 제41권3호
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• pp.468-486
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• 2017

In this study, three kinds of wearable fashion prototypes were developed using 3D printers with the goal of developing a practical production method for daily clothes. Prototypes were modeled using Rhinoceros software and developed using FDM 3D printers and TPU filaments. The results of this study are as follows. First, it confirmed the possibility of FDM-type entry-level 3D printers as a tool to develop wearable fashion products. Second, TPU filaments that are soft and ductile are highly likely to be used as a clothing material. Third, patterns designed through the 3D modeling process can be sampled directly to a 3D printer and easily corrected and supplemented. Fourth, it was confirmed that TPU prints of about 1.00mm thickness can be sewn with fabric using sewing machines through the development of 'Prototype 1' and 'Prototype 2'; in addition, hand stitching is also possible. Fifth, as in the case of 'Prototype 3', it is possible to fabricate a garment fit enough to the body if the clothing configuration is designed to connect the basic module using TPU filaments. In the future, the development of wearable fashion prototypes using various materials and 3D printing technology will help diversify everyday clothes.

• 디지털융복합연구
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• 제14권3호
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• pp.329-335
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• 2016

본 논문의 목적은 운용자가 2D와 3D 영상을 주시할 경우 영상피로를 정량적으로 비교하는 것이다. 16명의 20대 남 여가 2D와 3D 영상을 10분간 관람을 한 후, 관람 전과 후의 Flicker Fusion Frequency(FFF)와 Cyversickness가 측정되었다. 관람 전과 후의 두 종속변수를 비교함으로써 정량적으로 3D가 2D에 비해 어느 정도 영상피로를 발생시키는지를 이론적 고찰과 함께 과학적인 기기와 방법으로 측정하였다. 주관적인 척도인 Cybersickness 증가율은 2D에 비해서 3D가 4배, FFF 감소율은 3D가 2D에 비해 2배 높은 결과를 보였다. 본 연구는 일반적으로 3D 영상이 2D 영상에 비해 영상피로를 크게 유발함을 과학적인 방법과 객관적인 데이터로 증명했다는데 의의가 있다.

• 한국콘텐츠학회논문지
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• 제7권7호
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• pp.87-95
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• 2007

본 연구에서는 미래의 영상 콘텐츠를 조작하는 사용자 인터페이스(User Interface)가 3차원 중심으로 변화할 것이라 예측하여, 지금까지의 2차원 인터페이스와 3차원 인터페이스간의 공통점과 차이점을 GUI(Graphic User Interface)의 원칙을 기준으로 연구하고 3차원 인터페이스의 특징을 가상현실의 원리를 통해 살펴보고자 하였다. 이러한 이론적 연구를 바탕으로 실재의 2차원 인터페이스를 3차원 인터페이스로 변경 제작하여 설문조사를 실시하였으며 개혁확산이론에 근거하여 작성된 설문조사의 분석을 통해 2D와 3D 인터페이스를 비교하고 3D 인터페이스가 차세대 영상 콘텐츠의 주력 인터페이스가 될 수 있는 지의 가능성의 여부를 타진해본 결과 기존의 인터페이스를 대신하여 더 많은 시장가치를 지닌 인터페이스로서의 면모를 발견할 수 있었다.