• Proceedings of the KIEE Conference
• /
• 2002.11b
• /
• pp.234-236
• /
• 2002

The Co-Gen System which maximize energy efficiency was installed at the industrial plants at the initial stage. However Small Scale Co-Gen System was expanded even to the general end-users such as housing and building owing to ESCO business recently. For this SSC, inter-connected operation to the utility is desirable due to voltage and frequency fluctuation following to unbalance between power output and load. Then voltage unbalance with utility system, frequency, increase of short circuit capacity, reclosing, and ALTS etc. should be fully considered for the inter-connected operation. Voltage variation, protection coordination, Co-Generators single running, and short circuit capacity should also be solved. To research the method and solve the problems through the field test and application, we study individual customers Co-Gen System as a case study.

• KCI Concrete Journal
• /
• v.14 no.3
• /
• pp.111-120
• /
• 2002

This study proposes a joint model consisting of different types of members as a new structural system, and then investigates the resulting structural behavior. The joint model consists of a concrete-filled steel tube column (CFT) together with a steel reinforced concrete at the end plus reinforced concrete beam at the center. For comparison, two other joint models were designed, that are, a CPT with a reinforced concrete beam, and a CFT with a steel reinforced concrete at the end plus steel concrete beam at the center, then their joint capacity and rigidity, energy absorption capacity, etc., were all investigated. From the results, the CFT column with a steel reinforced concrete at the end plus steel concrete beam at the center was outstanding in terms of its capacity and rigidity. The results of this analysis demonstrate that an adequate connection type and reinforcement method with different materials of increasing the rigidity, thereby producing a capacity improvement along with protection from pre-fractures.

• Journal of the Korean GEO-environmental Society
• /
• v.10 no.6
• /
• pp.49-60
• /
• 2009

In order to develop a new rockfall protection fence using high carbon steel wire rod (HSWR) material instead of the conventional wire rope material, the author has conducted the laboratory strength tests of both materials and their connections, and carried out evaluation of absorbing rockfall energy through the vertical field rockfall tests. The vertical filed rockfall tests showed that the new rockfall protection fence with 12 rows of the HSWR could absorb more rockfall energy than 50 kJ which stands for the typical design criteria. In addition, when the quantity of HSWR was increased up to the 16 rows, the capacity of absorbing energy was greatly improved. The new rockfall protection fence was successfully applied to the highway rock-cut slope. As a result of the filed application, its constructability was similar to the conventional fence, but its total image was improved as simple and clean. The total construction cost was saved up to 20% in comparison with the conventional one.

• 대한방사선방어학회:학술대회논문집
• /
• 2011.04a
• /
• pp.116-117
• /
• 2011

• Applied Chemistry for Engineering
• /
• v.33 no.3
• /
• pp.296-301
• /
• 2022

Due to the fact that zirconium based metal-organic frameworks (Zr-MOFs), such as UiO-66, have a large specific surface area and excellent selective adsorption capacity, Zr-MOFs are gaining attention as materials that can provide protection from the attack of chemical warfare agents in battleground. However, most of the metal-organic frameworks have an issue of selective adsorption capacity degraded by water molecules when exposed to the atmosphere, because of the weak metal-organic ligand bonds and the presence of voids. Therefore, polydimethylsiloxane (PDMS), a representative hydrophobic polymer material, was coated on the surface of UiO-66 to enhance the sustainability of the diisopropyl methylphosphonate (DIMP) sorption capacity in the battleground condition. Through the analysis of surface structure and organic functional group distribution of PDMS coated UiO-66, silicon was confirmed to be evenly coated. The contact angle increased by over 30° for the PDMS coated UiO-66, indicating that the hydrophobicity was improved. In addition, both the UiO-66 and PDMS coated UiO-66 were used as adsorbents for DIMP, a similar chemical warfare agent, to investigate the durability of adsorption capacity in a high humidity environment. The PDMS coated UiO-66 showed higher durability of adsorption capacity for 20 days than that of pristine UiO-66.

• Journal of Communications and Networks
• /
• v.9 no.2
• /
• pp.198-209
• /
• 2007

This paper provides a thorough study on shared segment protection (SSP) for mesh communication networks in the complete routing information scenario, where the integer linear program (ILP) in [1] is extended such that the following two constraints are well addressed: (a) The restoration time constraint for each connection request, and (b) the switching/merging capacity constraint at each node. A novel approach, called SSP algorithm, is developed to reduce the extremely high computation complexity in solving the ILP formulation. Basically, our approach is to derive a good approximation on the parameters in the ILP by referring to the result of solving the corresponding shared path protection (SPP) problem. Thus, the design space can be significantly reduced by eliminating some edges in the graphs. We will show in the simulation that with our approach, the optimality can be achieved in most of the cases. To verify the proposed formulation and investigate the performance impairment in terms of average cost and success rate by the additional two constraints, extensive simulation work has been conducted on three network topologies, in which SPP and shared link protection (SLP) are implemented for comparison. We will demonstrate that the proposed SSP algorithm can effectively and efficiently solve the survivable routing problem with constraints on restoration time and switching/merging capability of each node. The comparison among the three protection types further verifies that SSP can yield significant advantages over SPP and SLP without taking much computation time.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.13 no.12
• /
• pp.6190-6213
• /
• 2019

For small-scale vector data, restrictions on watermark scheme capacity and robustness limit the use of copyright protection. A watermarking scheme based on robust geometric features and capacity maximization strategy that simultaneously improves capacity and robustness is presented in this paper. The distance ratio and angle of adjacent vertices are chosen as the watermark domain due to their resistance to vertex and geometric attacks. Regarding watermark embedding and extraction, a capacity-improved strategy based on quantization index modulation, which divides more intervals to carry sufficient watermark bits, is proposed. By considering the error tolerance of the vector map and the numerical accuracy, the optimization of the capacity-improved strategy is studied to maximize the embedded watermark bits for each vertex. The experimental results demonstrated that the map distortion caused by watermarks is small and much lower than the map tolerance. Additionally, the proposed scheme can embed a copyright image of 1024 bits into vector data of 150 vertices, which reaches capacity at approximately 14 bits/vertex, and shows prominent robustness against vertex and geometric attacks for small-scale vector data.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.21 no.3
• /
• pp.107-116
• /
• 2007

The introduction of new renewable energy is going on increase with the second plan of the Korean Government "Technology Development, Utilization and Popularization of New Renewable Energy". In general, it is connected to the power system due to the nature of it's source characteristics but it's interconnection operation impacts on the power system planning and operation. The operation schemes of the existing power distribution system are based on the unidirectional power flow, but unidirectional power flow changes to bidirectional power flow due to the interconnection operation of new renewable energy. It degrade the existing protection coordination system and power quality of the power distribution system. Thus, the technical evaluation process of the interconnection of new renewable energy are necessary. In this paper, the characteristics of the existing automatic recloser and sectionalizer are reviewed and interconnection capacity evaluation method of the DR(distributed resources) in the existing automatic recloser-sectionalizer protective coordination system are proposed.

• KIEAE Journal
• /
• v.8 no.1
• /
• pp.93-98
• /
• 2008

As high rise buildings and large span spatial structures are constructed, new composite members and construction techniques are continuously developed. Wide flange steel beam can be easily constructed but the fire proofing protection is necessary and the cost is high. Nowadays environmental pollution of structures is becoming a big issue. The material of fire proofing protection is not allowed to use for structural members in several countries because it cab be a cause of environment pollution. Composite beam is a new hybrid beam system which is not needed a fire proofing protection process. Composite beam has better construction capacity than that of RC system and has more economic advantages than that of wide flange steel beam. In this paper, structural design guide lines of composite beam were provided to apply design and construction.

• International Journal of Internet, Broadcasting and Communication
• /
• v.5 no.1
• /
• pp.18-22
• /
• 2013

We introduce, in this paper, a novel approach of protection mechanism for data which are transmitted not only between the networked devices but also between the digital media devices. As the devices are getting more powerful and more storage capacity, they can process the encoded/encrypted data autonomously. However, all devices must know the secret key that used to encrypt data, and also use secure method to distribute that key. Moreover, there are no protection mechanisms supporting end-to-end copy protection which result in the fact that the data passed through various devices can be manipulated or captured. Therefore, we propose a RFID-based key distribution and protection mechanism to resolve these problems.