• Korean Journal of Computational Design and Engineering
• /
• v.22 no.1
• /
• pp.59-69
• /
• 2017

Internal capacity of a refrigerator is an important indicator for design and purchasing criteria. The components facing the internal space may have holes or gaps between parts. In traditional way, design engineers manually remodeled the parts to fill the holes and the gaps for enclosed boundary of the internal space. Then they calculated internal volume by subtracting the assembly of parts from its enclosing volume. However, filling holes and gaps is not an automated process requiring a plenty of labor and time. In this research, we have developed a voxel-based method to estimate the internal volume of a refrigerator automatically. It starts transforming all components facing the interior space into voxels and fills all holes and gaps automatically by the developed hole-filling algorithm to form a completely closed boundary of the assembly. Then, it identifies the boundary voxels that are facing to the internal voxels with any part of the component. After getting the intersection points between the boundary voxels and the surfaces of components, it generates the boundary surface of triangular facets with the intersection points. Finally, it estimates the internal volume by adding volume of each tetrahedron composed of a triangle of boundary surface and an arbitrary point.

• Journal of Microbiology and Biotechnology
• /
• v.13 no.4
• /
• pp.613-619
• /
• 2003

The polyketide backbone of rifamycin B is assembled by the type I rifamycin polyketide synthase (PKS) encoded by the rifA-rifE genes. In order to produce novel analogs of rifamycin via engineering of the PKS genes, inactivation of the ${\beta}-ketoacyl:acyl$ carrier protein reductase (KR) domain in module 8 of rifD, by site-specific mutagenesis of the NADPH binding site, was attempted. Module 8 contains a nonfunctional dehydratase (DH) domain and a functional KR domain that is involved in the reduction of the ${\beta}-carbonyl$ group, resulting in the C-21 hydroxyl of rifamycin B. This mutant strain produced linear polyketides, from tetraketide to octaketide, which were also produced by a rifD-disruption mutant as a consequence of premature termination of the polyketide assembly. Another attempt to replace the DH domain of module 7, which has been considered nonfunctional, with a functional homolog derived from module 7 of rapamycin-producing PKS also resulted in the production of linear polyketides, including the heptaketide intermediate and its precursors. Premature release of the carbon chain assembly intermediates is an unusual property of the rifamycin PKS. that is not seen in other PKSs such as the erythromycin PKS.

• ALGAE
• /
• v.34 no.2
• /
• pp.99-109
• /
• 2019

Habitat-forming species increase spatial complexity and alter local environmental conditions, often facilitating the assembly of plants and animals. We conducted a trait-based approach to algal assemblages associated with the freshwater bryozoan, Pectinatella magnifica. Association with algae leads to the inner bodies of the bryozoans being colored green; this is frequently observed in the large rivers of South Korea. We collected the green-colored gelatinous matrices and phytoplankton from waterbodies of the two main rivers in South Korea. Algal assemblages within the colonies and in the waterbodies were compared using the three diversity indices (richness, diversity, and dominance), and the composition of functional groups (FGs) and morphologically based functional groups (MBFGs) between the colonies within and outside of P. magnifica colonies. The most dominant and common species within the colonies were Oscillatoria kawamurae and Pseudanabaena catenata, both of which were assigned to the same FG (codon S1). Of the algal assemblages within the colonies, the dominance was higher, while the richness and diversity were lower, than those in the waterbodies. There was variation in the compositions of FGs and MBFGs in the waterbodies outside the colonies. Total nitrogen and orthophosphate led to dominance, and were significant factors for the variation in FGs in the waterbodies, whereas there were no such significant factors within the colonies. This trait-based approach to the community structure of associated algae provides the status and habitat gradient of these communities, which are stable, isolated, and consistent with the overgrowth of shade-adapted tychoplanktonic cyanobacteria.

• Journal of Ocean Engineering and Technology
• /
• v.33 no.2
• /
• pp.153-160
• /
• 2019

Welding often results in welding distortion during the assembly process. The welding distortion of thin-plate structures such as the living quarters of ships and offshore installations is a more significant problem than in the case of thick-plate structures. Pre-stressing/heating and fairing, which are additional works to mitigate and control welding distortion, are inevitable, and the construction planning is accordingly delayed. In order to prevent welding distortion and minimize the additional work during the assembly process, increasing the plate thickness and/or the number of stiffeners may be a simple solution, but it may give rise to problems related to cost and weight. In this study, the welding distortion control effect of the type of stiffeners on the door openings of various living quarter structures was investigated using an experimental method and a finite element method. The results showed the feasibility of mitigating and controlling the welding distortion, and the optimum selection of the type of stiffeners was confirmed.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.20 no.6
• /
• pp.146-155
• /
• 2012

This study aims to analyze durability by comparing displacement on vibration at driving bicycle frame models of 1, 2, 3 and 4. Among maximum equivalent stresses at 4 kinds of models, model 1 has highest value with 410.39 MPa and becomes 30 times than model 4 with lowest value. The natural frequency number at Model 4 increases more than the other models. Among four models, the number of frequency at model 1 becomes lowest at harmonic vibration with real loading condition. In cases of four kinds of models, the maximum stress is shown near the assembly of rear wheel and the maximum displacement is shown near saddle assembly at this harmonic condition. The structural result about this study can be effectively utilized on the design of bicycle frame by investigating durability and prevention against its damage.

• Journal of the Korean Society for Precision Engineering
• /
• v.9 no.4
• /
• pp.36-43
• /
• 1992

This paper presents a hierarchical real-time operation control and monitoring scheme of the FMS/CIM center which has been implemented at the Automation and Systems Research Institute of Seoul National University. The hierarchical structure of the whole scheme consists of three lavers. The upper layer is in charge of on-line scheduling, computer network control, shop-floor monitoring and command generation for AGV dispatching, machining, assembly, inspection, set-up, etc. The middle layer has six modules, which are installed in the FMS host computer with the upper layer and run on the multi-tasking basis. Each module is connected to one of six cell controllers distributed in the FMS model plant and transfers operation command down to each cell controller through the Ethernet/TCP-IP local area network. The lower layer is comprised of six cell control software modules for machining cell, assembly cell, inspection cell, set-up stations. AS/RS and AGV. Each cell controller reports the status of the manufacturing facilites to the middle layer as well as ecxecuting the appropriate sequence control of the manufacturing processes.

• Journal of Korean Library and Information Science Society
• /
• v.25
• /
• pp.167-206
• /
• 1996

Some conclusions can be derived form the study : 1) The script of Japan author's name for 3 years(1960-1962, not published by the National Assembly Library but by Korea Library Association)and that of 1963's was arranged by their mother tongue although they had not the "author index". 2) "Periodical's Index" which the publication of National Assembly Library was not accept the principle that the person's name should be pronounce and script by one's mother tongue. It means that the Library was not accept the uniqueness of personal name. 3) Because the arrangement of the same person's name is mixed with one's mother tongue pronunciation and Korean one that they are scattered each another. 4) The same surname and the same Chinese character has different arrangement because of pronunciation rule of Korean language. 5) The same person's name was regarded as a different one because of nonaccurate name transcription. 6) A Japanese name was transcribed as Hangul with Korean pronunciation. 7) A Japanese name was transcribed as Hangul with Korean pronunciation and added Chinese Character in parenthesis. 8) A same Japanese name was regarded as a different one when it was transcribed with Chinese character and Hangul. 9) The arrangement of a same person's name was different when between the surname and forename has one space and has not. 10) "Author Index" is not playing as a role of name authority file.a role of name authority file.

• 대한공업교육학회지
• /
• v.45 no.2
• /
• pp.1-20
• /
• 2020

The purpose of this study is to develop an assembly-type liquid level control experimental equipment and a hands-on activity task that can be applied to the class so that students studying the chemical industry can easily understand the liquid level control. For this purpose, the content elements related to liquid level control in the chemical industry practice course of the 2015 revised curriculum was analyzed, a hands-on activity task with an assembly-type liquid level control experimental equipment was and developed. And then, expert verification was also performed and the hands-on activity task was applied to 19 students of S meister high school. The results obtained through this are as follows. First, the existing completion-type liquid level control experimental equipment was explored, and based on this, a new assembly-type liquid level control experimental equipment that can be assembled by students and used for practices was designed and manufactured. Second. by analyzing the contents of the NCS-based 'Chemical Process Maintenance Operation' practical course of the 2015 revised curriculum, learning contents related to level control were extracted. Among the contents related to the level control, the practice with understanding the process flow chart, manufacturing the level control experimental equipment, measuring the flow rate, and checking the level control phenomenon were conducted with the assembly-type liquid level control experimental equipment to systematically learn the level control.

• Journal of Magnetics
• /
• v.16 no.4
• /
• pp.350-362
• /
• 2011

The principal objective of this study was to develop a scanning technique that helps patients reduce their anxiety and relax their physical tension in the MRI system. The study targeted 10 healthy persons with no medical history of anxiety disorder in the past and with no current clinically diagnosed anxiety disorder, as well as 10 patients who were currently experiencing an anxiety disorder during the MRI scanning. The focusing board assembly was self-manufactured to conduct a clinical experiment via MRI scans. As a method to confirm the efficacy of the experiment, the bio meter was used to measure brainwaves from the study targets that were divided into the normal person group (A), who felt no anxiety in the MRI system and the experimental group, (B) who did experience anxiety in the MRI system. The two groups were compared between the cases in which the focusing board assembly was used and not used after measurements were conducted using the model MRI system and the bio meter. According to the comparison and analysis results, low measurements of the ${\alpha}$ wave indicate highly effective relaxation of tension. In the normal person group, the ${\alpha}$ wave measurement showed almost no difference between cases in which the focusing board assembly was used and cases in which it was not used. In the experimental group, the $\acute{a}$ wave measurements were lower in cases in which the focusing board assembly was used than in cases in which the focusing board assembly was not used; this was indicative of a profound relaxation effect.

• Proceedings of KOSOMES biannual meeting
• /
• 2018.06a
• /
• pp.137-137
• /
• 2018