• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.2
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• pp.267-276
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• 2009

Nowadays, numerous of valuable internet services are available not only for personal computer but also for mobile appliances in wireless network environment. Therefore, as the amount of contents is increased for those services, the storage limitation on mobile devices has became a significant issue. In this paper, we present a new block-level storage network protocol, iATA (Internet Advanced Technology Attachment) as a solution to the above problem. iATA is designed to transport ATA block-level data and command over the ubiquitous TCP/IP network. With iATA, a mobile appliance is able to access and control the ATA storage devices natively through network from anywhere and at anytime as if the storage devices is attached locally. We describe the concepts, design and diverse consideration of iATA protocol. Based on the benchmark experiments and application exploitation, we strongly believe that iATA as a light-weight protocol is efficient and cost-effective to be used as a storage network protocol on a resource limited device that utilizes common-off-the-shelf storage hardware and existing IP infrastructure.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.10
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• pp.1858-1865
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• 2007

In this paper, we introduce the design and implementation of satellite IP modem. The designed satellite IP modem shows the performance of 0.2% overhead, BER=10-5 when Eb/No=6dB, frequency offset of 8KHz, data rate up to 1536Kbps, $F_{if}=140MHz$. The designed system is verified through software simulation and then implemented with MPC86x communication processor, TMS320C6416 DSP, and Altera FPGA. Since each hardware unit is implemented in daughter board for modularity, we can reduce the development time and easily improve the performance with using better processor. Linux is used for embedded OS because it shows better performance in IP manipulation multitask processing, and hardware control through device driver. The implemented system is tested and verified with channel simulator. Since the proposed IP modem shows small size and light weight, that can be used anywhere with easy if you need IP environment.

• FLOWER RESEARCH JOURNAL
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• v.18 no.3
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• pp.171-178
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• 2010

This work is for selecting superior media which is similar to Peat Moss that is in general use as media of Gymnocalycium mihanovichii for Export such as 'Hwang wall' but lower price. The result on growth of 7 kinds of media (Peat Moss, BM6 Culture Medium, Coco Peat, Hydro Cray, Hydro Ball, Hugato, Vermiculite) which are applied watering (overhead irrigation, sub irrigation) based on bichemical analysis including chemical, physical analysis are following. The result of bi-chemical analysis shows that Coco Peat was stabilized planting after 90 days and Hydro Ball has high water holding capacity. The experimental result of growth in grafted cactus 'Hwangwall' shows Coco Peat is similar to Peat Moss on organic matter and in case of inorganic media, Hugato, Vermiculite, Hydro Cray made satisfactory results. But, the weight of inorganic media is too light to be tied. Consequently, Coco Peat and sphagnum moss as organic media has lower price and the condition of growth is analogous to Peat Moss. On the other hands, Hydro Ball was chosen as a substitute of Peat Moss in inorganic media.

• Journal of the Korea Convergence Society
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• v.10 no.11
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• pp.297-302
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• 2019

A-pillar is closely related to safety for the purpose of protecting the bodies of passengers by mitigating the impact that may be caused by the vehicle being overturned while driving. Therefore, the A-pillar should protect these parts from a variety of dynamic loads. This study result is thought to contribute for the strength and durability of A-pillar by designing two types of parts before making this product and analyzing the product which thickness is adjusted for the light weight of vehicle. If this study result is practically applied to the parts of A-pillar in a car, it is considered that the damage can be protected by the durability verification of design. By utilizing the data of analysis and design on the strength and durability of automotive A-pillar in this study, the esthetic sense can be given by being grafted onto the real automotive part.

• Journal of the Korean Magnetics Society
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• v.8 no.6
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• pp.388-394
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• 1998

We designed and fabricated an improved null-type torque magnetometer for measuring magnetic anisotropy of magnetic materials. This torque magnetometer has a measurement range of $~{\pm}15$ dyne.cm, and the range can be controlled. Resolution is ~0.0005 dyne.cm. Noise level is less than 0.01 dyne.cm with one measurement, and less than 0.004 dyne.cm with 10 averaged measuremets. The precision is less than 0.5 %. In contrast to typical null-type torque magnetometers, we placed a small ferrite magnet in the Helmholtz coil, instead of placing coil in the permanent magnet. From this novel sturucture, we can design a geometrically isotropic and relatively light-weight sample rod. Also, we can prevent the effect of input and output lines of coil exposed in the magnetic field in torque meter. Consequently, our novel null-type torque magnetometer can have a better sensitivity, faster response time, and smaller distortion of torque curve than commercially available torque magnetometers.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.3
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• pp.609-616
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• 2019

This paper proposes a design plan of short-term temporary housing for the victims by disaster. Also construction workability and residential environment evaluated by mock-up. In particular, in the event of a disaster, victims have lived the auditorium or gymnasium of the nearby school which is an emergency shelter. However, there was a problem of livability. Therefore, it is the purpose of study to provide temporary housing that resides within 30 days. For this purpose, a composite panel with light weight and insulation select to produce mock-up. The mock-up complete in about an hour. This is because it is made only of the composite panels. The composite panels confirm to be easy to load and construct. And mock-up evaluates insulation and waterproofing performance in the laboratory. As a result, Mock-up has insulation and waterproofing performance. This suggests an alternative to short -term temporary housing.

• The Journal of the Korea Contents Association
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• v.19 no.7
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• pp.291-303
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• 2019

For cities with ancient buildings at core areas, night lighting is an effective means to demonstrate their history and culture. In this regard, night scenes of these ancient buildings are evaluated from multiple aspects, such as color rendition, brightness ratio affected by ambient light and technological realization of lighting facilities. This study builds a visual evaluation system for night scenes of ancient buildings based on three dimensions, namely ancient architecture carrier performance, visual perception and technological realization, and explains specific evaluation sub-criteria one by one. In addition, this study adopts Analytic Hierarchy Process (AHP) to analyze the impact of each sub-criteria item on the weight of the whole evaluation system, and conducts a consistency test to show that the evaluation system meets the reasonable requirements of hierarchy setting. Moreover, relative importance of each sub-criteria item may be determined based on their corresponding weights.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.3
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• pp.35-42
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• 2021

The research of amplifier have been actively conducted to replace the Traveling Wave Tube Amplifier (TWTA) in the mmWave. For Solid State Power Amplifiers (SSPA), which combine semiconductor-type devices to obtain high output, Low-loss, high-efficiency combination techniques are required to meet the required output as the output of a single relatively low device is relatively low. In this paper, we design and produce an 8-way waveguide combiner and a reflective loss of more than 20dB and a binding efficiency of 85% or more were identified. Field analysis calculates the critical power inside the combiner. It secured stable Power Ratings and built-in coupler for power monitoring to achieve miniaturization and light weight.

• Steel and Composite Structures
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• v.46 no.4
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• pp.497-512
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• 2023

Using light weight concrete as infill material in conventional cold-formed steel (CFS) shear wall systems can considerably increase their load bearing capacity, ductility, integrity and fire resistance. The compressive strength of the filler concrete is a key factor affecting the structural behaviour of the composite wall systems, and therefore, achieving maximum compressive strength in lightweight concrete while maintaining its lightweight properties is of significant importance. In this study a new type of optimum polystyrene lightweight concrete (OPLC) with high compressive strength is developed for infill material in composite CFS shear wall systems. To study the seismic behaviour of the OPLC-filled CFS shear wall systems, two full scale wall specimens are tested under cyclic loading condition. The effects of OPLC on load-bearing capacity, failure mode, ductility, energy dissipation capacity, and stiffness degradation of the walls are investigated. It is shown that the use of OPLC as infill in CFS shear walls can considerably improve their seismic performance by: (i) preventing the premature buckling of the stud members, and (ii) changing the dominant failure mode from brittle to ductile thanks to the bond-slip behaviour between OPLC and CFS studs. It is also shown that the design equations proposed by EC8 and ACI 318-14 standards overestimate the shear force capacity of OPLC-filled CFS shear wall systems by up to 80%. This shows it is necessary to propose methods with higher efficiency to predict the capacity of these systems for practical applications.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.22 no.6
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• pp.31-36
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• 2022

In this paper, we present the design, manufacture and test results of Backend unit for SAR(Synthetic Aperture Radar) that can be applied on a small satellite. The Backend unit for SAR was designed with a control/storage board, TRX(transmission and receiving) board and a power supply board as a single unit in consideration of the applying of a small satellite. The control/storage board uses RFSoC to generate wideband chirp signal, generate operating timings, and perform control and calculations for SAR operation. The TRX board is designed to convert the wideband chirp signal generated by the control/storage board to the operating frequency of X-band by up-converting the frequency. Since small size, light weight, and low cost are important consideration for small satellite, MIL/Industrial grade components were appropriately applied and the at the same time it was designed to ensure mission life through the radiation test, analysis and space environment tests.