• Journal of the Korean Society for Railway
• /
• v.2 no.2
• /
• pp.15-20
• /
• 1999

철도의 초창기부터 선로 기술자들은 다음과 같은 목적을 위하여 최적의 궤도 표준을 달성하도록 노력하여 왔다. ㆍ 레일 이음매 보수의 제거 ㆍ 궤도 수명의 증가 ㆍ 더 높은 운전 속도와 더 무거운 하중을 위한 시설의 마련 ㆍ 승차감의 개선 이들 목적을 달성함에 있어 오랜 기간을 통하여 진보가 이루어져 왔으며, 이것은 장척과 장대 레일의 생산에서 가장 중요한 용접의 기술에 크게 의지하였다. 본고에서는 장대용접레일의 생산과 관련된 플래시 버트(Flash butt) 용접 기술의 원리와 고속철도용 장대용접 레일의 생산 등을 위하여 건설된 중앙궤도기지의 시설과 설비에 관하여 간략하게 소개한다.(중략)

• 월간 기계설비
• /
• s.131
• /
• pp.22-24
• /
• 2001

• Journal of the Microelectronics and Packaging Society
• /
• v.27 no.4
• /
• pp.47-54
• /
• 2020

Integration of active and passive waveguides is an essential component of the photonic integrated circuit and its elements. Butt joint is one of the important technologies to accomplish it with significant advantages. However, it suffers from high optical loss at the butt joint junction and need of accurate process control to align both waveguides. In this study, we used beam propagation method to simulate an integrated device composed of a laser diode and spot size converter (SSC). Two SSCs with different mode properties were combined with laser waveguide and optical coupling efficiency was simulated. The SSC with larger near field mode showed lower coupling efficiency, however its far field pattern was narrower and more symmetric. Tapered passive waveguide was utilized for enhancing the coupling efficiency and tolerance of waveguide offset at the butt joint without degrading the far field pattern. With this technique, high optical coupling efficiency of 89.6% with narrow far field divergence angle of 16°×16° was obtained.

• Special Issue of the Society of Naval Architects of Korea
• /
• 2005.06a
• /
• pp.192-197
• /
• 2005

A welding bead height is closely related to the efficiency of welding work, and the height of 3mm is used in the conventional practice of butt welding. in the present paper, the modification of bead height from 3mm to 6mm is considered to increase the efficiency and work productivity of butt welding on bottom plate (of BONGA FPSO actually built in SHI shipyard). Therefore, fatigue analysis has been carried out using simplified method based on the DNV Rules. It is found that the minimum fatigue life is about 594 years and the butt welding details with 6mm bead height has sufficient strength and resistance against fatigue.

• 한국가스학회:학술대회논문집
• /
• 1998.09a
• /
• pp.323-329
• /
• 1998

• 월간 기계설비
• /
• s.140
• /
• pp.29-36
• /
• 2002

도시가스안전관리기준통합고시 중 일부가 산업자원부고시 제2002-31호가 지난 3월 9일 개정되었다. 이 고시에는 그 동안 우리 협회 가스시공위원회(위원장 이영일)가 PE관 버트 융착 시공기준에 따른 문제점을 건의한 것이 받아들여져 2002년 3월 1일부터 착공되는 공사부터 PE관은 동일한 호수의 관종류를 사용토록 개정되었다.

• Journal of the Korea Society of Computer and Information
• /
• v.27 no.11
• /
• pp.39-46
• /
• 2022

In this paper, we propose a multi-task model that can simultaneously predict general-purpose tasks such as part-of-speech tagging, lemmatization, and dependency parsing using the UD Korean Kaist v2.3 corpus. The proposed model thus applies the self-attention technique of the BERT model and the graph-based Biaffine attention technique by fine-tuning the multilingual BERT and the two Korean-specific BERTs such as KR-BERT and KoBERT. The performances of the proposed model are compared and analyzed using the multilingual version of BERT and the two Korean-specific BERT language models.

• Korean Chemical Engineering Research
• /
• v.55 no.4
• /
• pp.561-566
• /
• 2017

Butt-fusion welding process is used to join the polymeric pipes. Recently, some researchers suggest the curved surface to enhance a welding quality. We investigated how curved welding surface affects heat and flow behaviors of polymer melt during the process in 2D axisymmetric domain with finite element method, and discussed the effect to the welding quality. In this study, we considered HDPE pipes. In heat soak stage, curved phase interface between the melt and solid is shown along the shape of welding surface. In jointing stage, squeezing flow is generated between curved welding surface and phase interface. The low shear rate in fusion domain reduces the alignment of polymer to the perpendicular direction of pipes, and then this phenomenon is expected to help to enhance the welding quality.

• Journal of the Korea Society of Computer and Information
• /
• v.27 no.11
• /
• pp.131-138
• /
• 2022

Git's commit message is closely related to the project life cycle, and by this characteristic, it can greatly contribute to cost reduction and improvement of work efficiency by identifying risk factors and project status of project operation activities. Among these related fields, there are many studies that classify commit messages as types of software maintenance, and the maximum accuracy among the studies is 87%. In this paper, the purpose of using a solution using the commit classification model is to design and implement a complex classification model that combines several models to increase the accuracy of the previously published models and increase the reliability of the model. In this paper, a dataset was constructed by extracting automated labeling and source changes and trained using the DistillBERT model. As a result of verification, reliability was secured by obtaining an F1 score of 95%, which is 8% higher than the maximum of 87% reported in previous studies. Using the results of this study, it is expected that the reliability of the model will be increased and it will be possible to apply it to solutions such as software and project management.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 1995.03a
• /
• pp.203-210
• /
• 1995

The rapid progress of automobile industry has led to a demand for sheet metal products and the new forming technology for complex product is required. In Deep Drawing process of steel sheet, especially stainless steel sheet at room temperture, some intermediate annealing need to be added to lessen strain hardening effect. The present study is concerned with the wram deep drawing of stainless steel sheet. In order to reduce the number of working process. the limit drawing ration is considered as main parameter. In this study, the effect of process variables such a sblank holder force, working temperature and lubricant on limit drawing ration is investigated . Experiments are carried out for the hemisherical and sqare shape at room and warm temperature respectively. The drawing loads and thickness deviation accoring to process variables measured . As the result of apploying those experimental data to the commerical butt product, the number of process can be reduced and good quality of products can be obtained.