• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.11a
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• pp.384-387
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• 2006

Recently, the method of the apartment building design has been changed from wall type structures to moment structures. With like this reason, dry walls we used plentifully. Especially, the gypsum board was used from previously plentifully however the weak point of it is difficult to maintain because it weak strength. For the improvement of gypsum board, light weight concrete panel using cement board is used recently. As this study is the research of the series t on the development of non-bearing light weight concrete panel using bottom ash, the purpose of this study is to obtain basic data for application in the field. The results are that the structure 1 satisfies domestic standard concerned with sound insulation between households at the laboratory and field test.

• IEMEK Journal of Embedded Systems and Applications
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• v.14 no.6
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• pp.339-346
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• 2019

Multi-axis servo systems are widely used in various fields such as industiral systems for improving production efficiency, robotics and complex systems where many mechanical devices and sensor systems are connected. Such a servo system requires that the servo control technique to realize the synchronization of the drive shaft in the steady state and transient conditions and to control so as to follow the target track in order to improve product precision and production efficiency. In addition, embedded type hardware is required for smooth control of the entire multi-axis system. Therefore, this paper uses hardware based on FPGA which is widely used in digital signal processing field and various control system because hardware design change is easy and parallel processing is possible. In addition, Labview based servo motor control program was studied that can control the servo motor by ensuring the performance and flexibility of the FPGA and follow the target trajectory according to various speed processing and accurate timing synchronization.

• Journal of the Korea Safety Management & Science
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• v.8 no.6
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• pp.91-108
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• 2006

RFID/USN is important infrastructure of the ubiquitous society. And so, It is various and practical research is attempted. These two base technology have physical characteristic and complement relationship. Like this relationship is applied Following example that is system research which manages warehouse stocks and conditions. First, We adhere RFID Tag at the Pallet of the warehouse and do identification goods. And then, It grasps the environment state information of stocks with sensor module which has Zigbee wireless communication function. From like this process RFID Tag information and jop-control command of sensor node also it is exposed to air. Therefore, We control sensor node in USN/RFID environment through the mobile device. And system design for the security Apply of the process is main purpose of this paper's. We propose the condition and function of the mobile device to the secondary. And We define the relation of the sensor node with RFID to be arranged to a warehouse. Finally, This paper is designed to find a trade-off of the following viewpoints. First, We offer suitable sensor-control information to a actual manager. Second, We offer RFID tag security approach to control the action of the sensor. Third, It increases the survivability of sensor node form.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2005.06a
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• pp.388-394
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• 2005

A typical honeycomb sandwich panel consists of two thin, high-strength facings bonded to a thick, light-weight core. Each component by itself is relatively weak and flexible, but when it combind in a sandwich panel they produce a structure that is stiff, strong, and lightweight. In addition to use in honeycomb sandwich panels, honeycomb is used for energy absorption, radio frequency shielding, light diffusion, and to direct air flow.Accordingly, the usage of honeycomb sandwich structure is very widely applied to the aircraft, the automobile, and marine industry, etc., because of these advantages. Generally, this honeycomb sandwich structure is manufactured by autoclave process.In this study, the honeycomb sandwich structure was produced by prepreg. To prove the suitability the honeycomb sandwich structure with prepreg, The optimum design of the skin materials and honeycomb sandwich structure were evaluated with the theory of stress analysis.

• Journal of the Korean Geotechnical Society
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• v.37 no.5
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• pp.33-46
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• 2021

After the Gyeongju earthquake, which was the largest in the history of measuring instruments in Korea in 2016, and after the Pohang earthquake, where the pillars of pallet structures were destroyed in 2017, the seismic design standards for all domestic facilities have been revised and supplemented. In particular, during the investigation of the Pohang Earthquake damage cases, liquefaction damage that occurs mainly in countries with strong earthquakes such as the United States, Japan, and New Zealand was found, so studies are being conducted in depth to improve seismic design standards. In this study, the liquefaction potential assessment in the recently revised seismic design standard for port and harbor was reviewed, and an applicability review was conducted focusing on the newly cited liquefaction potential index (LPI). At this time, by varying the thickness and location of the sandy soil where liquefaction can occur, the LPIs for various cases were calculated and compared. Also, 22 LPI values in the practical port area were compared and reviewed along with performance of the liquefaction assessment based on the site response analysis using the boring-hole data of the actual 22 port sites.

• 한국HCI학회:학술대회논문집
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• 2007.02a
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• pp.328-333
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• 2007

RFID와 sensor network의 두 기반 기술은 독특한 물리적 특정을 가지며 상호 보완적인 관계를 가지고 있다. 이러한 관계는 창고 안 물품의 상태파악과 입출 재고를 관리하는 형태로 응용된다. 창고 내 물품 보관 단위인 파렛트(Pallet) 에 RFID 태그를 부착하여 입/출고시의 물품을 식별한다. 그리고 Zigbee 무선 통신기능을 가진 센서 모듈에 의해 물품의 환경 상태 정보를 파악한다. 이후 현장 관리자나 소비자들은 이동형 단말장치를 통해 현장에서 다양한 USN 상의 정보들과 상호작용 한다. 이 과정에서 이동형 단말장치를 통한 RFID tag 정보와 센서 노드의 접근이 공중파 상에 노출 된다. 이러한 센서 노드 접근을 보호하기 위해 추가적인 칩 설계 등의 비용 지불로 기밀 노출에 대처할 수 있다. 이에 대한 대안으로 인프라형태로 놓여진 RFID tag와 단말장치에 탑재될 RFID 리더를 활용해 더 적은 비용으로 보안 서비스를 받고자 한다. 그래서 유비쿼터스 환경에서 센서 노드에 대한 접근을 제어하기 위해 RFID tag를 지역키(local key) 처럼 사용한다. 또한 이 과정에 보안이 적용된 프로토콜을 설계 하는 것이 본 논문의 주된 목표이다.

• Bulletin of the Society of Naval Architects of Korea
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• v.30 no.2
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• pp.44-52
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• 1993

선박에 있어서 철의장품은 종류와 수량이 다양하고 형상이 불규칙하여 대부분의 사업장에서 설계 전산화가 이루어지지 못하고 있는 실정이다. 의장설계실에서는 이를 전산화하기 위하여 먼저 철의장품의 표준을 제정 및 극대화하고 설계작업절차와 물량의 흐름을 전산과 연계하여 체계화 및 표준화하였다. 또한 선박의 전구역에 설치되는 철의장품들을 관련 양식과 함께 국제표준을 근거로 BASICA CADDS, SURFACE DESING, SDDP(structural Design ＆ Detailing Package) SOFTWARE를 이용하여 2차원(2-dimension) 및 3차원(3-dimension) 데이터베이스(database)화 하였으며 이를 POP-UP MENU를 이용, 쉽게 선택함으로써 모델링(modeling) 작업시수를 대폭 감소 시켰으며, 그래픽(graphic)에서 추출한 의장품의 데이터(data)를 의장품의 표준정보 FILE과 연계하여 라벨(LABEL) 및 치수(DIMENSION)를 기입하여 배치도를 추출하고 의장품의 제작, 설치, 계산 및 관리에 소요되는 설치도, 제작도 및 관련 보고서인 BOM(bill of material), PML(pallet material list), 의장제작품 LIST, COG(center of gravity), 관리점 등을 자동추출 및 관리전산망(PC-lan)과 연계할 수 있는 DECOM(철의장 전산설계 전용 package)을 89년에 개 발하여 의장설계에 적용하여 왔으며 ORACLE사의 RDBMS(relational database management system)를 도입하여 이를 보완하므로써 정보의 일관화 및 공유화가 가능하게 되었다. 그 결과 설계 M/H절감, 생산성 향상, 자재 및 관련 정보 전달에 혁신적인 변화 향상을 가져오게 되었다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.12
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• pp.1139-1147
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• 2011

In this paper, a design and fabrication of GaN power amplifier for the S-band frequency (400 MHz bandwidth) are presented. A combining path using ${\lambda}$/4 transmission line is implemented for GaN pallet amp. Both the combiner with suspended-type transmission structure for low-loss and the suspended stripline coupler with aperture coupling for auto gain control are realized for achieving high-power high-efficiency amplifier. Proposed power amplifier demonstrated a 5 kW peak output power, 27.8 % efficiency, 67 dB gain without ALC and a 4 kW peak output power, 25.5 % efficiency, 0.1 dB droop at 200 usec pulse width and 10 % duty with ALC.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.12A
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• pp.1238-1245
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• 2006

Interest to the RTLS that is one of RFID applications is increasing in recent. The RTLS(Real Time Locating Systems) is one of applications for locating and tracking using RFID tags which are attached to something like container, pallet, or all the things. This paper presents the design and the implementation of an RTLS system using 433MHz active RFID tags and use radio frequency to provide the scalability. Our system we developed using RFID platform takes into account an RTLS standard. Also, in this paper a routing protocol is included to data delivery to server via each reader. In order to perform the evaluation, in addition, some experiments in out door are performed and results such as error metric and distance are also included. Furthermore, simulation for the routing protocol we supposed is also included.

• Journal of the Korea Society of Computer and Information
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• v.28 no.10
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• pp.171-178
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• 2023

In this paper, we propose a smart automated warehouse to maximize space utilization. Previous elevator-type automatic warehouses were designed with a maximum payload of 100kg on trays, which has the problem of extremely limiting the number of pallets that can be loaded within the space. In this paper, we design a smart warehouse that can maximize space utilization with a maximum vertical stiffness of 300kg. As a result of the performance evaluation of the implemented warehouse, the maximum payload was 500.6kg, which satisfied the original design and requirements, the lifting speed was 0.5m/s, the operating noise of the device was 67.1dB, the receiving and forwarding time of the pallet was 36.92sec, the deflection amount was 4mm, and excellent performance was confirmed in all evaluation items. In addition, the PLC control method, which designs the control UI and control panel separately, was integrated into the PC system to improve interoperability and maintainability with various process management systems. In the future, we plan to develop it into a fully automatic smart warehouse by linking IoT sensor-based logistics robots.