• Journal of Forest and Environmental Science
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• v.25 no.1
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• pp.75-84
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• 2009

This study was conducted to investigate the physical properties of wood chip for fuel processing with woody biomass. Seven species are selected and processed for testing physical properties by 3-type wood chippers which are commonly used in Korea. Wood chips produced by self-propelled drum chipper and fixed type wood chipper equipped with separator were uniform in size and shape. It was shown that the bulk density of produced wood chips was decreased with increasing the wood chip layer thickness, and oak chips prepared by self-propelled drum chipper and fixed type wood chipper showed the highest bulk density.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.21 no.8
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• pp.973-982
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• 1997

Effect of vortex generator on the heat transfer enhancement of electronic chips is investigated using naphthalene sublimation technique. Experiments are performed for a single chip and chip arrays, and shape of vortex generator, position of vortex generator, stream wise chip spacing and air velocity are varied. Local and average heat transfer coefficients are measured on the top surface of simulated electronic chips, and compared with those obtained without vortex generator. In case of a single chip, heat transfer augmentation is seen only on the upstream portion of chip surface, while heat transfer enhancement is found on the whole surface for chip arrays. Rectangular wing type vortex generator is found to be more effective than delta wing.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.33 no.3
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• pp.265-268
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• 2009

We present the experimental study to realize a DNA separation chip using asymmetrically-switched nonuniform electric fields. The DNA separation chip redistributes DNA molecules within a specific area based on the size- and field-dependent nonlinearity of DNA drift velocity. The present chip is composed of a width variable channel to distribute nonuniform electric field, a DNA loading slit and a pair of electrodes to apply electric field. We focus on the design of DNA separation chips with identifying the nonlinearity of DNA drift velocity using three different DNA molecules (11.1kbp, 15.6kbp, and 48.5kbp) in the chips. It is demonstrated that different size of DNA shows different net migration in different direction under the asymmetrically-switched nonuniform electric field.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.04a
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• pp.240-245
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• 2000

This paper presents the experimental study of drilling for duralumin A2024 with intermittently decelerated feed rate. It is achieved through a programmed periodic increase and decrease in the feed rate using a machining center. The following experimental result were performed with the objective of solving chip to disposal problems. In conventional drilling of aluminum, long continuous chips are produced that wind around the drill causing difficulties in eliminating chips from the cutting zone. In order to acquire the basic data necessary to regulate the chip profile, the relationship between cutting variables and chip shape was investigated. The following conclusions are established from the experimental results. At a suitable feed fluctuation ratio, intermittently decelerated feed drilling proved successful in breaking chips to appropriate lengths while maintaining stable cutting. Thus, it is an effective method for improving chip disposal. The amplitude of the dynamic component of cutting force in intermittent feed frilling is influenced by the feed fluctuation ratio.

• Preventive Nutrition and Food Science
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• v.2 no.1
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• pp.11-16
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• 1997

Alkaline cooking and processing properties of domestic maize were evaluated by comparing to those of imported control maize(Asgrow 404). Domestric maize varieties were hydrated more rapidly and had lower dry matter losses during alkaline cooking than control maize due to softer endosperm texture and incomplete removal of pericarps. Domestic maize varieties produced masas with proper handling properties when nixtamals had 50~52% moisture. However, masas produced from domestic maizes were puffed dur-ing baking and frying process due to the release of more free starch granules in the masa than control masa. Tortilla chips prepared from domestic maizes absorbed more oil during frying and had slightly higher water content with darker color than tortilla chips prepared from control maize. Among the domestic maize hybrids, KS42/Fla2BT113 had more acceptable kernel characteristics of tortilla chips than other varieties.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.43 no.3
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• pp.128-136
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• 2011

In order to investigate the relationship between the prices of wood chips and pulps, regression analysis and cointegration test were conducted. Test results indicated that pulp producers adjusted pulp price in response to the change in wood-chip price and there were a long-run relationship between these prices. This implied that by raising the selling price of pulp, pulp producers avoid profit loss incurred by the increase in the wood-chip price. The existence of cointegration between wood chips and pulp prices implied that pulp producers were competing when they set the selling price of pulp.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.18 no.4
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• pp.362-368
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• 2009

In general, circuit board assemblies experience various mechanical loadings during assembly and in actual use. The repeated cyclic bending can cause electrical failures due to circuit board cracks, solder interconnects cracks, and the component cracks. In this paper, we report on the failure characteristics of semiconductor chips under the repeated cyclic bending. We first describe a new 4-point bending tester, which is developed according to JEDEC standard No. 22B113. The performance of the tester is then estimated through actual experiments. Test results reveal that the cracks first occur on the outer balls around 20,000 cycles and gradually propagate to the inner balls where cracks are found around 70,000 cycles.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.540-540
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• 2012

Selective detection of single nucleotide polymorphism (SNP) of Cytochrome P450 2C19 (CYP2C19) was carried out by the PNA chips which were electrically-interfaced with interdigitated nanogap electrodes (INEs). The INEs whose average gap distance and effective gap length were about ~70 nm and ${\sim}140{\mu}m$, respectively, were prepared by the combination of the photo lithography and the surface-catalyzed chemical deposition, without using the e-beam lithography which is almost inevitable in the conventional lab-scale fabrication of the INEs. Four different types of target DNAs were successfully detected and discriminated by the INE-based PNA chips.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.30B no.6
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• pp.86-92
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• 1993

In this paper, we present a VLSI chip design of Multi-layer Bidirectionsl Associative Memory with good error-correction performance. The MBAM neural chip utilizes inner product implementation schems with binary storage and analog calculation.. Multi-layer can be constructed by direct cascading of these chips, and the number of neurons is expandable by parallel connection of these chips. We made proto-type chips and interface board to test the expansion. Currently the Chip has 32 input nodes, 32 output nodes, and can store up to 48 patterns, 32x48x2 SRAMs are included in the chip.

• Genomics & Informatics
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• v.9 no.2
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• pp.89-91
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• 2011

DNA chips are becoming increasingly popular as a convenient way to perform vast amounts of experiments related to genes on a single chip. And the importance of analyzing the data that is provided by such DNA chips is becoming significant. A very important analysis on DNA chip data would be clustering genes to identify gene groups which have similar properties such as cancer. Clustering data for DNA chips usually deal with a large search space and has a very fuzzy characteristic. The Particle Swarm Optimization algorithm which was recently proposed is a very good candidate to solve such problems. In this paper, we propose a clustering mechanism that is based on the Particle Swarm Optimization algorithm. Our experiments show that the PSO-based clustering algorithm developed is efficient in terms of execution time for clustering DNA chip data, and thus be used to extract valuable information such as cancer related genes from DNA chip data with high cluster accuracy and in a timely manner.