• Journal of the Korean Institute of Telematics and Electronics A
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• v.30A no.3
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• pp.104-113
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• 1993

A new switchbox router, called CONQUEROR, is proposed in this paper. The proposed CONQUEROR efficiently routes large switchbox routing area using divide-and-conquer technique. The CONQUEROR consists of three phases` namely, partition of large routing area and assignment of optimal pins of sub-area, detailed routing of each sub-ared, reassignment of pins after rip-up. First, large switchbox routing area is partitioned into several sub-areas and each sub-area contains 4-6 detailed grids. Then pins are assigned on boundary of sub-area by the estimated weight. Secondly, when global pin assignment is completed on all sub-areas, each sub-area is routed using detailed router. Also, detailed routing consists of three pases` layerless maze routing, assignment of layer using coloring, and rip-up and reroute. Lastly, if detailed routing of any sub-area fails,reassignment of pins after rip-up is invoked. Detailed routing is performed for the failed sub-area again. Benchmark test cases have been run, and on all the benchmark data known in the literature CONQUEROR has performed as well as or better than existing switchbox routers.

• Journal of Acupuncture Research
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• v.18 no.5
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• pp.77-91
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• 2001

Backgrounds and purpose : The acupuncture of oriental medicine is very important in treatments. Until now it was been researched according to the meridian and qi xue(氣血) phenomenon of oriental medicine's theory. Acupuncture will show more objective index to observe the meridian. And then, I studied the effects on the thermal change of the Taeyon($L_9$) and Chungbu($L_1$) following acupuncture stimulation. Objective and Methods : This study was performed from December 1999 to February 2000 on 60 healthy students. The objective was divided into two groups, those are the control group A(N=30) that no acupuncture stimulation, the group B(N=30) of acupuncture stimulation on Taeyon($L_9$). First, in the control group A, I took a picture Taeyon($L_9$) Chungbu($L_1$) Taenung($P_7$) Chondol($CV_{22}$) area for 30 men without any stimulation with the Digital Infrared Thermograph Imaging(D.I.T.l.) and did same area, 10min after. Second, in the acupuncture stimulation group B, we took a picture Taeyon($L_9$) Chungbu($L_1$) Taenung($P_7$) Chondol($CV_{22}$) area for 30 men without any stimulation with the Digital Infrared Th - ermograph Imaging(D.I.T.I.), and then stimulate acupuncture on Taeyon($L_9$) and took a picture same area, 10min after. Results : 1. In healthy men, average skin temperture on Taeyon($L_9$) area was lower than Chungbu($L_1$) area about $3.0^{\circ}C$, in the Lt. Taeyon($L_9$) and Chungbu($L_1$) area was lower than Rt. Taeyon($L_9$) and Chungbu($L_1$) area. 2. In the acupuncture stimulation group B, the skin temperature of both side Taeyon($L_9$) area showed the increase or decrease significantly. But both Taenung($P_7$) area did not showed significantly. 3. In the acupuncture stimulation group B, the skin temperature of both side Chungbu($L_1$) area showed the increase or decrease significantly. But both Chondol($CV_{22}$) area did not showed significantly. 4. The thermal changes of the area which is a meridian point in the Lung Meridian of the acupuncture stimulation group on Taeyon($L_9$) different from other Meridian with significantly change. Conclusion : The acupuncture stimulation on Taeyon($L_9$) affected the thermal change of the area which is a meridian point, in the Lung Meridian. And then I could relate these results with the existence of the meridian and meridian point. Thus, continuous thermographic study will be needed for the existence of the meridian and meridian point.

• Journal of The Korean Society of Agricultural Engineers
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• v.64 no.3
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• pp.25-32
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• 2022

To understand the distribution characteristics of PM_2.5 concentration in the Saemangeum Reclamation Area and nearby areas, three points of the background area, the occurrence area, and the affected area were selected and samples were collected for each season. The chemical composition was determined. As a result of analyzing the chemical composition contained in PM_2.5, NO₃^- (7.2 ㎍/m³), SO₄^2- (4.3 ㎍/m³), NH₄+ (4.3 ㎍/m³), OC (2.5 ㎍/m³), Si (1.3 ㎍/m³) m³) and EC (0.5 ㎍/m³) seemed to be the main components, and NO₃-, SO₄^2-, NH₄⁺, which are components that form secondary particles, occupied a large proportion. The composition ratio of PM_2.5 was investigated in the order of ion component (56.8%) > Unknown (27.4%) > carbon component (11.8%) > heavy metal component (4.0%). During the PM_2.5 high concentration case days, the ionic component accounted for 90.7% during atmospheric stagnation cases, whereas the chemical composition ratio was in the order of ionic component (51.7%) > heavy metal component (41.5%) > carbon component (6.8%) during yellow dust cases. It was found that the characteristic of PM_2.5 in the Saemangeum reclaimed land and surrounding areas is mainly influenced by outside (domestic and overseas) throughout the year. Ion components accounted for the largest portion of PM_2.5 components in this area, but there were few sources of SOx and NOx emission in the Seamangeum area, which are precursors for secondary particle formation. Therefore, it is judged that most of these are generated and influenced as a secondary reaction in the atmosphere from the outside.

• 한국ITS학회:학술대회논문집
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• 2003.11a
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• pp.116-121
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• 2003

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.268-268
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• 2022

Protein is a major nutrient of food and has long been studied for nutritional and utility value. Among them, rice protein is attracting attention because of its hypoallergenic characteristics and nutritional value. Mutant DM225 with increased protein content was selected by EMS treatment on the weed rice Dharial. QTL analysis of Protein content was carried out using BC₂F₂ populations derived from a cross between "Hanareum2" as a recurrent parent and "DM225" as a donor parent. The protein content of populations was between 5~11%, with an average of 7.7%. To identify QTLs related to Protein content, 117 KASP markers(polymorphic ratio: 15%) showing polymorphisms between the parents were genotyped for the BC₂F₂ population. One QTL was detected between markers SK07 06 and SK07_10 on chromosome 7(LOD: 28.1). This QTL explained 71.4% of the phenotypic variance for Protein content. This QTL will be useful for protein-related rice breeding program.

• The Bulletin of The Korean Astronomical Society
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• v.36 no.2
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• pp.98-98
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• 2011

We have investigated solar flare probability depending on sunspot classification, its area, and its area change using solar white light data. For this we used the McIntosh sunspot groups with most flare-productive regions : DKI, DKC, EKI, EKC, FKI and FKC. For each group, we classified it into three sub-groups according to sunspot area change : increase, steady, and decrease. For sunspot data, we used the NOAA active region information for 11 years (from January 2000 to December 2010): daily sunspot class and its area corrected for the projection effect. As a result, we find that the mean flare rates and the flare probabilities for the "increase" sub-groups are noticeably higher than those for other sub-groups. In case of the (M+X)-class flares of 'kc' groups, the mean flare rates of the "increase" sub-groups are more than two times than those of the "steady" sub-groups. This is statistical evidence that magnetic flux emergence is an very important for triggering solar flares since sunspot area increase can be a good proxy of magnetic flux emergence. In addition, we have examined the relationship between sunspot area and solar flare probability. For this, we classified each sunspot group into two sub-groups: large and small. In the case of compact group, the solar flare probabilities noticeably increase with its area.

• Journal of Electrochemical Science and Technology
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• v.12 no.3
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• pp.339-345
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• 2021

Spent activated carbons (SACs) collected from a water treatment plant were regenerated and then adopted as electrochemical material in capacitors. The SACs used in this study were regenerated via two steps, namely thermal and chemical activation. However, during the activation process, the adsorbates were converted into ashes, which caused pore blockage and decreased specific surface area. The regenerated SACs were washed with acid solutions with different levels of acidity (strong: HCl, mild: H₃PO₄, and weak: H₂O₂) to remove the ashes. The regenerated SACs washed with HCl exhibited the highest specific surface area, although their capacitance was not the highest. Conversely, the specific surface area of regenerated SACs washed using H₃PO₄ was slightly lower than that of HCl, but exhibited higher capacitance and electrochemical stability. Although the strong acid removed the generated ashes in the pores efficiently, it could adversely affect their structural stability, which would lead to lower capacitance.

• Journal of the Korean Physical Society
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• v.81
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• pp.942-947
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• 2022

We report the electrical transport properties of a dual-gate graphene device placed on a CaF₂ substrate. A hexagonal boron nitride top-gate dielectric was introduced to confirm the electrical characteristics of the CaF₂/graphene transistor because it is difficult to inject sufficient carriers through the CaF₂ substrate owing to its thickness of 500 ㎛, and the typical ambipolar behavior of graphene with a slight n-doping effect was clearly observed. In addition, we used a polymethyl methacrylate (PMMA) film as a top-gate dielectric for large-scale graphene devices grown via chemical vapor deposition, which was transferred onto a CaF₂ substrate. We controlled the high gate leakage current caused by the breakdown of the polymer due to non-uniformity by applying the film-transfer process rather than the direct coating method on the graphene device. Furthermore, the transport properties of large-area graphene in contact with CaF₂ are discussed with respect to the effect of top-contacted PMMA.

• The Journal of the Korea Contents Association
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• v.21 no.12
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• pp.918-925
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• 2021

The perovskite solar cell is a next-generation solar cell that replaces the existing silicon solar cell. It is a solar cell device using an organic-inorganic hybrid material having a perovskite structure as a photoactive layer. It has advantages for the process and has shown rapid efficiency improvement over the past decade. In the process of commercialization of such perovskite solar cells, research and development for a large-area coating method should be carried out. As one of the large-area perovskite solar cell large-area coating methods, the slot-die coating method was studied. By using a meniscus to pass over the substrate and coating the solution, the 3D printer was equipped with a meniscus so that it could be coated. Variables that act during coating include bed temperature, coating speed, N₂ blowing interval, N₂ blowing height, N₂ blowing intensity, etc. By controlling these, the perovskite absorption layer was manufactured and the coating conditions for manufacturing large-area devices were optimized.

• Steel and Composite Structures
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• v.46 no.3
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• pp.403-416
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• 2023

This paper summarised and re-examined the theoretical basis of the commonly used design rule developed by Cochrane in the 1920s to consider staggered bolt holes in tension members, i.e., the s²/4g rule. The rule was derived assuming that the term two times the bolt hole diameter (2d₀) in Cochrane's original equation could be neglected, and assuming a value of 0.5 for the fractional deduction of a staggered hole in assessing the net section area. Although the s²/4g rule generally provides good predictions of the staggered net section area, the above-mentioned assumptions used in developing the rule are doubtful, in particular for a connection with a small gauge-to-bolt-hole diameter (g/d₀) ratio. It was found that the omission of 2d₀ in Cochrane's original equation appreciably overestimates the net section area of a staggered bolted connection with a small g/d₀ ratio. However, the assumed value of 0.5 for the fractional deduction of a staggered hole underestimates the staggered net section area for small g/d₀ ratios. To improve the applicability of the above two assumptions, a modified design equation, which covers a full range of g/d₀ ratio, was proposed to accurately predict the staggered net section area and was validated by the existing test data from the literature and numerical data derived from this study. Finally, a reliability analysis of the test and numerical data was conducted, and the results showed that the reliability of the modified design equation for evaluating the net section resistance of staggered bolted connections can be achieved with the partial factor of 1.25.