• Journal of the Korean Wood Science and Technology
• /
• v.18 no.2
• /
• pp.49-66
• /
• 1990

In order to identify an unknown wood sample native to Korea. the softwood databases(KSWCHUN; Korean SoftWood CHUN) and the hardwood databases(KHWCHUN; Korean HardWood CHUN) had been built. and the new computer searching programs(IDINEX; IDentification INformation EXpress) has been written in Turbo Pascal(V.5.0) and in Macro Assembly(V.5.0). The characters of the data were based on the 74 features of softwood and on the 148 features of hardwood which are a part of new "IAWA list of microscopic features for hardwood identification" published in 1989. For the purpose of this investigation the wood anatomical nature of 25 species of softwood(13 genera of 5 families) and of 112 species of hardwood(57 genera of 31 families) were observed under a scanning electron microscope and light microscope. and a lot of literature used. The IDINEX programs are based on edge-punched card keys. with several improvements. The maximum number of features in the IDINEX is 229. but that is fixed for a given database. Large numbers of taxa are handled efficiently and new taxa easily added. A search may be based on sequence numbers of features. Comparisons are made sequentially by feature and taxon using the entire suite of features specified to produce the list of possible matching taxa. The results are followings. (1) The databases of Korean wood and the searching programs(IDINEX) had been built. (2) The databases of Korean wood could be an information to search an unknown wood. (3) The databases would be valuable. for the new features, which were not mentioned in Korean wood up to the present. were observed in details. (4) The ultrastructures of the cell walls(warty layer) and crystals observed under a scanning electron microscope will be helpful to search an unknown wood in particular. (5) The searching process is more quick and accurate than the others. 6) We can obtain the information on the differences of a species from the other and search an unknown wood using probability. in IDINEX, (7) The IDINEX will be utilized to identify and classify an animal life, vegetable world, mineral kingdom, and so on.

• Fashion & Textile Research Journal
• /
• v.13 no.2
• /
• pp.269-278
• /
• 2011

This study aims at setting up productive capacity which can be usefully utilized for work management of apparel manufacturers. So as to achieve this goal, an apparel manufacturing company which has been operated by miniline system in Seoul was selected. Standard time and man-hour were calculated to create the accurate productive capacity by observing and measuring a work flow included cutting, sewing and finishing processes. And the result is as following. The standard time for each process was presented as cutting process 47004.5s, sewing process 671050.5s and finishing process 22426.3s. And 15284.4ms was computed as total procession man-hour per day of the manufacturer which is organized of 16 people. Also, the procession man-hour for each process was revealed as cutting process 396.7ms(2.6%), sewing process 14509.3ms(94.9%) and finishing process 378.5ms(2.5%). +Surplus was found in the productivity for each process included the cutting process(outshell, lining and seam process), the sewing process(preparation and arrangement process) and the finishing process. But, additional man-hour 52436.18ms was required because the productive capacity was calculated as -surplus(-13.9%) in the sewing process(part and assembly process). Therefore, a work schedule was planned based on the previous result. However, loading can be ideal when a capacity and a load become '0'. The object company should find the way to reduce allowance(26.25%) of the sewing process through reconstruction of consciousness and improvement in functions with analyzing works of operators. Also, they need to consider an additional supplement of the personnel.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.40 no.2
• /
• pp.199-206
• /
• 2016

Linear motion (LM) ball guides with rolling contact are core units of feed-drive systems. They are widely applied for precision machinery such as machine tools, semiconductor fabrication machines and robots. However, the friction force induced from LM ball guides generates heat, which deteriorates positioning accuracy and incurs changes of stiffness and preload. To accurately analyze the effects and apply the results to precision machine design, mathematical modeling of the friction force is required. In this paper, accurate formulation of the friction force due to rolling, viscous, and slip frictions is conducted for LM ball guides. To verify the reliability of the developed friction model, experiments are performed under various assembly, load and velocity conditions. Effects of frictional components are analyzed through the formulated friction model.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.42 no.8
• /
• pp.674-682
• /
• 2014

Radio Frequency Test Set (RFTS) is essential to verify Telemetry, Command & Ranging (TC&R) RF subsystem of both Low Earth Orbit (LEO) and Geostationary Earth Orbit (GEO) satellite during Assembly Integration & Test (AI&T). The existing RFTS was specialized for each project and needed to be modified for each new satellite. The new design enables RFTS to be used in various projects. The hardware and software was designed considering this and therefore it could be directly used in other projects within a similar test period without modification or inconvenience. It will be also easily controlled, modified, and managed through the extension in modularization according to each function and the use of COTS (commercial on-the-self) and this will improve system reliability. A more reliable RF test measurement is also provided in this new RFTS by using an accurate reference clock signal.

• Journal of Mechanical Science and Technology
• /
• v.17 no.7
• /
• pp.999-1010
• /
• 2003

Uninterrupted power supply has become indispensable during the maintenance task of active electric power lines as a result of today's highly information-oriented society and increasing demand of electric utilities. This maintenance task has the risk of electric shock and the danger of falling from high place. Therefore it is necessary to realize an autonomous robot system using electro-hydraulic manipulators because hydraulic manipulators have the advantage of electric insulation and power/mass density. Meanwhile an electro-hydraulic manipulator using hydraulic actuators has many nonlinear elements, and its parameter fluctuations are greater than those of an electrically driven manipulator. So it is relatively difficult to realize not only stable contact work but also accurate force control for the autonomous assembly tasks using hydraulic manipulators. In this paper, the robust force control of a 6-link electro-hydraulic manipulator system used in the real maintenance task of active electric lines is examined in detail. A nominal model for the system is obtained from experimental frequency responses of the system, and the deviation of the manipulator system from the nominal model is derived by a multiplicative uncertainty. Robust disturbance observers for force control are designed using this information in an H$\_$$\infty$/ framework, and implemented on the two different setups. Experimental results show that highly robust force tracking by a 6-link electro-hydraulic manipulator could be achieved even if the stiffness of environment and the shape of wall change.

• The Bulletin of The Korean Astronomical Society
• /
• v.42 no.1
• /
• pp.58.3-58.3
• /
• 2017

In a ${\Lambda}CDM$ universe, galaxies are believed to evolve by mergers and accretions. The debris resulting from such processes remains as diffuse, low-surface brightness structures, such as outer disks, stellar halos, and faint companions. These structures will give us fruitful insight into the recent mass assembly history of galaxies, but it is challenging to observe them due to their low surface brightness. In order to explore the structural properties of outskirts of nearby galaxies, we conduct deep wide-field imaging survey with KMTNet. Here we present a progress report of data reduction for the images of NGC 1291, a lenticular barred galaxy with outer rings. To achieve accurate flat fielding, we use dark sky flat and remove the sky gradient of each exposure with a polynomial fit. As a result, we are able to reach 1 sigma depth of ${\mu}_R{\sim}29.6\;mag\;arcsec^{-2}$. We expect to investigate the surface brightness profile of NGC 1291 in 1-D profile, and color-gradient in the outer part of the galaxy using the B- and R-band images.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.39 no.2
• /
• pp.78-84
• /
• 2006

A high performance liquid chromatography assay method for spiramycin in fish muscle was developed. The developed method was evaluated and validated by monitoring spiramycin in olive flounder (Paralichthys olivaceus), black rock fish (Sebastes schlegeli) and in live conger eel (Anguilla japonica) in fish farms and distribution centers. Using the developed method, the recovery rate was up to 82.4-88.8%, which was higher than that of conventional methods (77.6-87.1%). In particular, the proposed sample treatment protocol was suitable for use with fish samples to remove low molecular weight materials and pigments that could interfere an accurate analysis. The prepared stock solution was very stable, and it remained chemically stable for 5 weeks at $4^{\circ}C$. The performance limit of the developed method for spiramycin acid in fish muscle was 0.05 ppm. One hundred thirty-four fish samples including olive flounder, black rock fish and live conger eel were analyzed to evaluate the overall efficiency of the modified method and to monitor the actual condition of spiramycin usage in fish farms. Olive flounder and black rock fish were collected from fish farms in coastal areas of Korea, and live conger eels were purchased from a fish market in the Busan area from September 2001 to March 2002. According to the overall performance of the developed method, it was considered suitable for the monitoring of spiramycin in fish muscle. The suggested method of analysis for spiramycin in fish muscle is registered in the Korean Official Methods of Food Analysis and is currently tieing utilized for fishery products inspection by the Korea Food and Drug Administration and the National Fisheries Products Quality Inspection Service.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.38 no.6
• /
• pp.372-378
• /
• 2005

An analysis method of tetracyclines far fish and shellfish products containing large amount of low molecular materials and pigments was established. The recovery of the established analysis method for four tetracycline samples was $72-100\%$ and higher than other methods reported. Especially, proposed sample treatment protocol was shown to be effective for the removal of low molecular materials and pigments that tend to interfere with accurate analysis. The detection limit of oxytetracycline (OTC) and tetracycline (TC) from the sample was 0.02 ppm, and the detection limit of chlortetracycline (CTC) and doxycycline (DC) from the sample was 0.1ppm, To examine the efficiency of the established method and identify tetracycline usage in fish farms, tetracycline group antibiotics in the flounder being cultured was monitored. The improved method can be used for fish and shellfish products effectively and all surveyed fish farms have used tetracycline all the year round. The proposed method was adopted as official method for fishery products by Korean Food and Drug Administration in 2003 and it is being used by regulatory authority as National Fishery Products Quality Inspection Service.

• Journal of the Korean Society of Hazard Mitigation
• /
• v.6 no.4 s.23
• /
• pp.1-6
• /
• 2006

In terms of the speed-up of the conventional line, the research for a improved turnout was carried out continually around world. A turnout is known that it is the most unstable equipment structurally in the rail system. So, the turnout is needed more stable structure. An accurate assembly of turnout affects traveling qualify of turnout area and running safety. Therefore, a turnout which is pre-assembled at a factory by using the split PC sleeper is transported to construction site recently in advanced countries. In this paper, the performance measurements which estimate the safety of the split PC sleepers which are adopted for the first time to improve performance of turnout are implemented indoors. The split PC sleeper is one of components of the improved turnout. The test is considered of the worst ballast condition under the maintenance work as like STT(Swithc Tie Tamper) or MTT(Multiple Tie Tamper). These experiments results indicate that structural safety for the expansion joint of the split PC sleepers.

• The KIPS Transactions:PartB
• /
• v.16B no.2
• /
• pp.157-161
• /
• 2009

Minimum Letter Flips(MLF) and Weighted Minimum Letter Flips(WMLF) can perform the haplotype reconstruction more accurately from SNP fragments when they have many errors and gaps by introducing the related genotype information. And it is known that WMLF is more accurate in haplotype reconstruction than those based on the MLF. In the paper, we analyze two models under the conditions that the different rates of homozygous site in the genotype information and the different confidence levels according to the sequencing quality. We compare the performance of the two models using neural network and genetic algorithm. If the rate of homozygous site is high and sequencing quality is good, the results of experiments indicate that WMLF/GI has higher accuracy of haplotype reconstruction than that of the MCIH especially when the error rate and gap rate of SNP fragments are high.