• The Korean Journal of Ecology
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• v.23 no.2
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• pp.169-173
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• 2000

Seasonal distribution of ectomycorrhizal associations in various types of forest in a boreal forest in Manitoba. Canada was investigated. Alsohe relationship between ectomycorrhizal growth and pine pollen nutrients was examined. In four different forest stands, ectomycorrhizas tended to be lower in the spring than in the summer and fall samples. In addition. a mature jack pine (Pinus banksiana) stand showed higher mycorrhizal activities than a young jack pine stand. Growth of Suillus brevipes hyphae wa ts stimulated by additions of pollen representing mean pollen deposition in Mistik Creek study area after 30 and 70 days of growth with dextrose availability. This result suggests that the peak ectomycorrhizal activity is followed by pollen deposition in the study region and therefore, addition of pine and spruce pollen in early or middle of June in the boreal forest can be an important seasonal nutrient source for ectomycorrhizal growth.

• Proceedings of the KIPE Conference
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• 2003.11a
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• pp.206-209
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• 2003

This paper deals with stand-alone PV power generation system with charge and discharge controller for the LED road sign. Main power source of PV system are generally solar cell and battery. Therefore PV system can be classified into variable types in accordance with connection type between battery and solar sell. Mainly used on of them is direct connection type which has advantage such as simple structure and simple controller. To verify the proposed PV generation system for the LED road sign, the detail simulation and experiment results indicate that operating characteristics are verified by experiment with a laboratory prototype in this paper.

• Proceedings of the KIPE Conference
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• 1998.10a
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• pp.972-977
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• 1998

This paper deals with stand-alone Photovoltaic system(SPVS) with charge and discharge controller. Main power source of SPVS are generally solar cell and battery. Therefore SPVS can be classified into variable types in accordance with connection method between battery and solar cell array. Mainly used one of them is direct connection type which has advantages such as simple structure and simple controller. However most big drawback of this system is energy loss by voltage disharmony between solar cell array and battery. Therefore SPVS with charge and discharge controller which can operate solar cell array at maximum power point is designed and experimented with a laboratory prototype.

• Proceedings of the KIPE Conference
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• 1998.07a
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• pp.103-108
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• 1998

This paper deals with stand-alone Photovoltaic system(SPVS) with charge and discharge controller. Main power source of SPVS are generally solar cell and battery. Therefore SPVS can be classified into variable types in accordance with connection type between battery and solar cell. Mainly used one of them is direct connection type which has advantages such as simple structure and simple controller. However most big drawback of this system is energy loss by voltage disharmony between solar cell and battery. Therefore SPVS with charge and discharge controller which can operate solar cell at maximum power point is designed and analyzed by simulation in this paper.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.97-98
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• 2006

This study deals with the Transmission Error of gear tooth profile by modifying a Profile and lead of a surface of Tooth. First, we experimentally confirmed that the Transmission Error is a synthesis of the sliding Velocity between both gears. Since various types of Transmission errors appear in the experiments, we introduced definition of Transmission Error and The Optimism Design by modifying a surface parameters The test stand's performance is then evaluated through a series of multiple torque transmission error tests. Comparisons are made between data recorded before and after the test stand's redesign, and subsequently repeatability studies are performed to verify the veracity of the measured data. Finally, the experimental results are compared to the analytical predictions of two different gear analysis programs.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1998.10a
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• pp.209-215
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• 1998

This paper deals with stand-alone Photovoltaic system(SPVS) with charge and discharge controller. Main power source of SPVS are generally solar cell and battery. therefore SPVS can be classified into variable types in accordance with connection type between battery and solar cell. Mainly used one of them is direct connection type which has advantages such as simple structure and simple controller. However most big drawback of this system is energy loss by voltage disharmony between solar cell and battery. Therefore SPVS with charge and discharge controller which can operate solar cell at maximum power point is designed and analyzed by simulation in this paper.

• The Korean Journal of Ecology
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• v.21 no.5_1
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• pp.419-426
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• 1998

Twenty-two forest stands and one hundred and fourteen plant species were ordinated by a reciprocal averaging(RA) method to extract the major forest patterns of the Quercus forests in Mts. Wolak, choryong, Juhul and Bohyun. The RA stand ordination on the first and second axes revealed a gradient of vegetation. It is the gradient from the Quercus mongolica-dominated forest to the Quercus serrata-dominated forest or Quercus variabilis-dominated forest. An intermediate zone between the two forest types was recognized by the RA stand ordination. Especially the zone on Mt. Bohyun was evidently higher than those of the other mountains. The gradient also showed the environmental one from mesic to xeric habitats and from higher to lower altitudes. The RA species ordination showed the distribution center of each species in the above mentioned patterns of the forest vegetation.

• Journal of Power Electronics
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• v.13 no.6
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• pp.1070-1079
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• 2013

This paper develops an enhanced harmonic voltage compensator which is implemented with the aid of two repetitive controllers (RCs) in order to improve the output voltage performance of stand-alone distributed generation (DG) systems. The proposed harmonic voltage compensator is able to maintain the DG output voltage sinusoidal regardless of the use of nonlinear and/or unbalanced loads in the load side. In addition, it can offer good steady-state performance under various types of loads and a very fast dynamic response under load variations to overcome the slow dynamic response issue of the traditional RC. The feasibility of the proposed control strategy is verified through simulations and experiments.

• Journal of the Semiconductor & Display Technology
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• v.21 no.1
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• pp.136-141
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• 2022

In this paper, we designed, implemented, and verified the SLAM system that can be used on mobile devices. Mobile SLAM is composed of a stand-alone type that directly performs SLAM operation on a mobile device, and a mapping server type that additionally configures a mapping server based on FastAPI to perform SLAM operation on the server and transmits data for map visualization to a mobile device. The mobile SLAM system proposed in this paper is to mix the two types in order to make SLAM operation and map generation more efficient. The stand-alone type SLAM system was configured as an Android app by porting the OpenVSLAM library to the Unity engine, and the map generation and performance were evaluated on desktop PCs and mobile devices. The mobile SLAM system in this paper is an open source project, so it is expected to help develop AR contents based on SLAM in a mobile environment.

• Journal of the Korean Society of Costume
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• v.58 no.5
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• pp.13-34
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• 2008

In Headgear and Ornaments for Diadem in the Period of the Three States there was Conical Cap(or Pointed Cap), Feathered Cap(Trim), and Crown[Tree-typed Diadem and Tree and Antler-typed Diadem] was excavated from the tombs. Feathered Trim is 5 types, Feathered Trim I-A, Feathered Trim I-B, Feathered Trim II-A, Feathered Trim II-B, Feathered Trim II-C in according to upper part of central insert plate style. Feathered Trim I-A, I-B, II-B type was general style that was found in most of the old tombs in ancient Silla, Gaya. Feathered Trim II-A type was excavated from the only Silla tombs and II-C type was excavated from Gaya tombs. The Ornaments for Diadem in Baekje was excavated from the tombs is adorned with a arranged leaf-stems on either sides and the flower-shaped. They were distinguished with the original mode of Goguryeo and ancient Silla at the time. Tree-typed Diadem is five part in according to the Mountain(;山)-typed piled up. Only one Mountain(;山)-typed one in three stand-up ornament(I-1 type), and three step one in three stand-up one(I-2 type), modification one (I-3 type), three step one of four and five stand-up ones(I-4 type), and four step one of four and five stand-up ones (I-5 type). Tree and Antler-typed Diadem is three part in according to the step of Mountain(; 山)-typed and cross-shaped of the upper part. Three one of three step one of Mountain(;山)-typed and two Antler- typed (II-1 type), cross-shaped one(II-2 type), four step one(II-3 type).