• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2023년도 가을학술발표대회논문집
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• pp.155-156
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• 2023

In the case of steel door frames commonly found in general buildings, there are various assembly methods such as rivets, bolts, and welding, but the welding method is generally used. However, this welding joint method has many problems, such as distortion due to heat and damage due to external shock. In particular, when used as a fire door, problems may occur in the event of a fire due to distortion caused by heat from welding and the weak welded joint area. In the case of rivet or welded joints, when moved after assembly, joint loosening due to external shock may occur. Problems may arise where the bonding strength becomes weak. In addition, with the recent increase in high-rise buildings and larger buildings, when assembly is completed and brought to the site, a place is needed to store it, and in addition, there is a problem in that it has to be transported several times in small quantities to the installation site, which is another problem of time and cost loss. This is coming to the fore. In order to fundamentally solve this problem, we have researched and developed a non-welding door frame that can be assembled on site. We have researched and developed three assembly methods: screw-type, insert-type, and protrusion-type. Non-welded door frames are small in size and easy to package, making them advantageous for domestic and overseas exports.

• 한국건설관리학회논문집
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• 제23권6호
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• pp.89-100
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• 2022

최근, OSC(Off-Site Construction)기반 PC구조의 활성화를 위한 제도적 기반 마련의 일환으로 적정공사비 산정에 필요한 품셈 개발을 요구받고 있다. PC공법의 공사비는 공장제작-운반-현장설치의 단계로 구성된다. 최근 운반과 현장 설치는 부재(subsidiary materials)별 현장실태 조사 결과를 반영한 표준품셈 체계(standard product calculation system)를 제시하는 등 관련 연구가 진행되고 있다(Lee et al., 2021). 반면, 공장 제작 공사비 산정과 관련된 연구는 전무한 실정이다. 본 연구에서는 PC 공법의 공장제작 공사비 산정기준 마련을 위해 공장 제작 환경에 활용할 수 있는 품셈 체계를 제시하였다. 이를 위해 시공절차에 따른 작업 공종을 도출하였으며, 공종별로 연계된 표준품셈을 분석하여 작업 특성에 적합한 표준 투입인력을 산출하였다. 품셈 체계는 PC부재의 현장설치와 동일하게 기둥, 보, 벽체, 슬래브 부재로 구성하였으며, 공종별 기능공을 기준으로 부재별 기본공수를 제시함으로서 직접노무비의 산출이 가능하도록 하였다. 또한, 개별 부재의 규격(m³)에 따라 생산성이 변화되는 특성을 고려하여 부재 크기를 품의 할증 요소로 제시하였다. 본 연구결과는 현재 견적에 의해 재료비료 계상되는 PC공법의 공장제작 비용을 객관적으로 검증할 수 토대 마련에 기여할 수 것이다.

• Nuclear Engineering and Technology
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• 제55권4호
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• pp.1485-1494
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• 2023

The bow of the nuclear fuel assembly is a well-known phenomenon. One of the vital criteria during the history of nuclear fuel development has been fuel assembly's mechanical stability. Once present, the fuel assembly bow can lead to safety issues like excessive water gap and power redistribution or even incomplete rod insertion (IRI). The extensive bow can result in assembly handling and loading problems. This is why the fuel assembly's bow is one of the most often controlled geometrical factors during periodic fuel inspections for VVER when compared e.g. to on-site fuel rod gap measurements or other instrumental measurements performed on-site. Our proposed screening method uses existing video records for fuel inspection. We establish video frames normalization and aggregation for the purposes of bow measurement. The whole process is done by digital image processing algorithms which analyze rotations of video frames, extract angles whose source is the fuel set torsion, and reconstruct torsion schema. This approach provides results comparable to the commonly utilized method. We tested this new approach in real operation on 19 fuel assemblies with different campaign numbers and designs, where the average deviation from other methods was less than 2 % on average. Due to the fact, that the method has not yet been validated during full scale measurements of the fuel inspection, the preliminary results stand for that we recommend this method as a complementary part of standard bow measurement procedures to increase measurement robustness, lower time consumption and preserve or increase accuracy. After completed validation it is expected that the proposed method allows standalone fuel assembly bow measurements.

• 한국건축시공학회지
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• 제12권6호
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• pp.648-663
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• 2012

With recent attempts to improve quality and productivity, the prefabrication manufacturing system has been occupying an increasing share of the construction area. To minimize site work, material is more frequently being produced and partially assembled at a plant, and then installed at a site. For this reason, the production process is being divided and the materials are being delivered to the site after passing through multiple plants. With these changes in the production process, the materials delivery plan is becoming an important management point. In particular, as road transportation using trucks has a 71 percent share of the domestic transportation market, selecting the proper transportation path is important when delivering materials and equipment to a site. But the management system at the project design phase to calculate the delivery cost by considering the production process of the pre-fab material and the $CO_2$ emission at the material delivery phase is currently lacking. This study suggests a process design model for assembly production of the pre-fab material and transportation logistics based on carbon emission. The suggested model can be helpful to optimize the location of the intermediate plant. It is expected to be utilized as a basic model at the project plan and design phase when subcontractors make decisions on items such as materials procurement, selecting the production method, and choosing the location of the assembly plant.

• 국제학술발표논문집
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• The 1th International Conference on Construction Engineering and Project Management
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• pp.1193-1198
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• 2005

The pre-assembly takes a large portion of the fabrication cost of steel bridges. In order to save the fabrication cost through the improvement of the conventional pre-assembling process, this research investigates a numerical pre-assembly simulation as an alternative to current pre-assembling process. The 3D laser scanning was utilized in site and measuring data for steel box were analyzed. The productivity of pre-assembly simulation system is compared with the conventional pre-assembling system. This paper identifies feasibility on the alternative pre-assembling process and then proposes the scheme of the pre-assembly simulation system development satisfying the current pre-assembly inspection of standards.

• 대한안전경영과학회지
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• 제6권2호
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• pp.11-21
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• 2004

Objectives: The aim of this study is to determine prevalence and related factors of musculoskeletal symptoms in electronics assembly line workers. Method: A questionnaire survey was performed on 350 workers in In-chon city. The questionnaire consisted of questions on the general characteristics, work duration, working hours, hobby activity hours, housekeeping activity hours and standardized descriptions of NOISH on musculoskeletal symptoms. Result: Complaint rates of musculoskeletal symptoms by anatomical site were as follows: shoulder, 67% : neck, 40.4% : waist, 28.7% : wrist and hand, 27.1% : foot and leg, 14.4% : arm and elbow, 11.2%. Significantly higher prevalence of shoulder musculoskeletal symptom was found women than men, married than unmarried, less than 1hours housekeeping activity than over 1hours housekeeping activity. Multiple logistic regression analysis identified gender, marital status and housekeeping activity as the main affecting factors for shoulder musculoskeletal symptoms. Conclusions: The most prevalence of musculoskeletal symptoms was shoulder site. It was higher in married women and over 1hours housekeeping activity in a day. It is recommended that married women should be reduce housekeeping activity time.

• Biotechnology and Bioprocess Engineering:BBE
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• 제3권2호
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• pp.67-70
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• 1998

In order to understand the influence of ferroxidase center on the protein assembly and solubility of tadpole ferrin, three mutant plasmids, pTH58K, pTH61G, and pTHKG were constructed with the aid of site-directed mutagenesis and mutant proteins were produced in Eshcerichia coli. Mutant ferritin H-subunits produced by the cells carrying plasmids pTH58K and pTHKG were active soluble proteins, whereas the mutant obtained from the plasmid pTH61G was soluble only under osmotic stress in the presence obtained from the plasmid pTH61G was soluble only under osmotic stress in the presence of sorbitol and betaine. Especially, the cells carrying pTH61G together with the plasmid pGroESL harboring the molecular chaperone genes produced soluble ferritin. The mutant ferritin H-subunits were all assembled into ferritin-like holoproteins. These mutant ferritns were capable of forming stable iron cores, which means the mutants are able to accumulate iron with such modified ferroxidase sites. Further functional analysis was also made on the individual amino acid residues of ferroxidase center.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
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• pp.404-405
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• 2006

Microarray-based DNA chips provide an architecture for multi-analyte sensing. In this paper, we report a new approach for DNA chip microarray fabrication. Multifunctional DNA chip microarray was made by immobilizing many kinds of biomaterials on transducers (particles). DNA chip microarray was prepared by randomly distributing a mixture of the particles on a chip pattern containing thousands of m-scale sites. The particles occupied a different sites from site to site. The particles were arranged on the chip pattern by the random fluidic self-assembly (RFSA) method, using a hydrophobic interaction for assembly.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 추계학술대회 논문집 Vol.17
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• pp.472-475
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• 2004

Microarray-based DNA chips provide an architecture for multi-analyte sensing. In this paper, we report a new approach for DNA chip microarray fabrication. Multifunctional DNA chip microarray was made by immobilizing many kinds of biomaterials on transducers (particles). DNA chip microarray was prepared by randomly distributing a mixture of the particles on a chip pattern containing thousands of m-scale sites. The particles occupied a different sites from site to site. The particles were arranged on the chip pattern by the random fluidic self-assembly (RFSA) method, using a hydrophobic interaction for assembly.

• 디지털융복합연구
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• 제10권1호
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• pp.379-384
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• 2012

조립공정의 상세한 과정을 보여주기 위해 Script 언어를 사용하여 자동차 조립공정을 3D로 시뮬레이션 하였다. 3D 가시화 기술은 산업현장에서의 학습활동을 가시화하는데 최적의 방법이 될 수 있다. 특히 시뮬레이션은 자동차 관련하여 엔진 부분과 타이어부분에 대하여 조립과정을 3D로 자동화하여 보여줄 수 있도록 구현하였다. 특히 터치스크린을 바탕으로 하여 사용자가 실제로 작업도중에 학습할 수 있도록 실험하였다.