• Journal of Sensor Science and Technology
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• v.21 no.1
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• pp.75-81
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• 2012

Optimizing the tapping time of a blast furnace is important to a stable operation and life extension. To optimize the tapping time of the blast furnace, the location of Hearth Liquid Level should be recognized. There are several ways to measure the hearth liquid level in the blast furnace, such as Electromotive Force(EMF) measurement, pressure measurement by putting in nitrogen probe and manometry with strain gauge. In this paper, it will be discussed using strain gauge among the three methods. Conventional strain gauge must be revised periodically. Since, internal pressure, temperature of internal refractory material and wind pressure have effect on the strain gauge. However, static pressure value is required to compensate. To solve these problems, this paper suggests finding relationship between Hearth Liquid Level and strain gauge output, adding digital filter in strain gauge. Using the proposed method, it was possible to estimate the hearth liquid level and determine the appropriate tapping time. Usefulness of the proposed method through simulations and experimental results are confirmed.

• Journal of Biomedical Engineering Research
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• v.22 no.4
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• pp.359-368
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• 2001

A new knee-ankle-foot-orthosis(KAFO) which uses an automatically-controlled electromechanical wrap spring clutch for the knee joint was developed in the present study. It was found that the output voltage from the foot switches of the developed KAFO was proportionally increased with respect to the applied load. The output voltage from the infrared sensor also decreased as the knee flexion angle increased. The knee joint system for the new KAFO weighs only 780g lighter than any other commercially available developed system. In addition, the solenoid reduces the reaction time for the automatic control of the knee joint. The static torque of the clutch was measured for three persons, and it satisfied the normal knee extension moment during the pre-swing. Three-dimensional gait analyses for three different gait patterns (normal gait, locked-knee gait, controlled-knee gait) from five normal subjects were conducted. Controlled-knee gait showed the maximum knee flexion angle of 40.56$\pm9.55^{\circ}$ and the maximum knee flexion moment of 0.20$\pm$0.07Nm/kg at similar periods in the normal gait. Our KAFO system satisfies both stability during stance phase and free knee flexion during the swing phase at the proper period during the gait cycle. Therefore, our KAFO system would be very useful in various low extremity orthotic applications.

• Journal of the Korea Institute of Military Science and Technology
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• v.14 no.3
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• pp.380-387
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• 2011

In this paper, we considered the authoritative representation of Command and Fire Control System(CFCS) for the surface ship that was the engineering level model to develop system specifications and to analyze operational concepts on the concept design phase and to analyze military requirements, effectiveness and performance for the system. The engineering level model of CFCS can be used in simulation independently of the surface ship's type, and also it takes reuse, interoperability, and extension into consideration. The detailed sub-models, internal and external data interface, data flow among each sub-model, sensor and weapon models about the engineering level model of CFCS was defined. It was verified via engineering level simulations according to the V&V process.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.03a
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• pp.15-25
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• 2004

This paper outlines a new convergence acceleration de-signed to solve scramjet flowfields with zones of re-circulation. Named the “marching-window”, the algorithm consists of performing pseudo-time iterations on a minimal width subdomain composed of a sequence of cross-stream planes of nodes. The upstream boundary of the subdomain is positioned such that all nodes upstream exhibit a residual smaller than the user-specified convergence threshold. The advancement of the downstream boundary follows the advancement of the upstream boundary, except in zones of significant streamwise ellipticity where a streamwise ellipticity sensor ensures its continuous progress. Compared to the standard pseudo-time marching approach, the march-ing-window is here seen to decrease the work required for convergence by up to 24 times for supersonic flows with little streamwise ellipticity and by up to 8 times for supersonic flows with large streamwise separated regions. The memory requirements are observed to be reduced sixfold by not allocating memory to the nodes not included in the computational subdomain. The marching-window satisfies the same convergence criterion as the standard pseudo-time stepping methods, hence resulting in the same converged solution within the tolerance of the user-specified convergence threshold. The extension of the marching-window to the weakly-ionized Navier-Stokes equations is also discussed.

• Journal of Sensor Science and Technology
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• v.24 no.2
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• pp.124-130
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• 2015

This paper presents a high performance HIGHT processor that can be applicable for CCM mode. In fact, HIGHT algorithm is a 64-bit block cipher. However, the proposed HIGHT extends the basic block length to 128-bit. The proposed HIGHT is operated as 128-bit block cipher and it can treat 128-bit block at once. Thus, it can be applicable for the various WSN applications that need fast and ultralight 128-bit block cipher, in particular, to be operated in CCM mode. In addition, the proposed HIGHT processor shares the common logics such as 128-bit key scheduler and control logics during encryption and decryption to reduce the area overhead caused by the extension of data block length. From the simulation results, the circuit area and power consumption of the proposed HIGHT are increases as 40% and 64% compared to the conventional 64-bit counterpart. However, the throughput of the proposed HIGHT can be up to two times as fast. Consequently, the proposed HIGHT is useful for USN and handheld devices based on battery as well as RFID tag the size of circuit is less than 5,000 gates.

• Journal of Power System Engineering
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• v.18 no.6
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• pp.166-173
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• 2014

In this study, a laminated composite material with dispersing aluminum oxide powder between the CFRP laminate plies, and also CFRP composites without aluminium oxide powder were fabricated for Mode I experiments using the DCB specimen and a tensile test. The behavior of the crack and the change of the interfacial fracture toughness were evaluated. Also in order to evaluate the damage mechanism for the crack extension, the AE sensor on the surface of the DCB test specimen was attached. AE amplitude was estimated for CFRP-alumina and CFRP composite. And the fracture toughness was evaluated by the stress intensity factor and energy release rate. The results showed that an unstable crack was propagated rapidly in CFRP composite specimen along with the interface, but crack propagation in CFRP-alumina specimen was relatively stable. From results, we show that aluminium oxide powder spreaded uniformly in the interface of the CFRP laminate carried out the role for preventing the sudden crack growth.

• Proceedings of the Korea Information Processing Society Conference
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• 2019.05a
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• pp.342-345
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• 2019

드론의 동작 검증을 위한 테스트는 최종적으로 드론이 운용될 환경에서 이루어진다. 그러나 테스트 비용이 크고 테스트 비행 중 파손의 위험이 있기 때문에 시뮬레이션을 통한 사전 검증을 수행하는 것이 중요하다. 시뮬레이션은 SIL 방식이나 HIL 방식으로 이루어지는데 추가적인 외부 센서를 활용하는 경우 검증하기가 어렵다. SIL에서는 검증을 위해 가상의 외부 센서 구현이 필요하다. HIL 에서는 실제 센서를 사용하므로 가상의 외부 센서 구현은 필요 없다. 그러나 테스트 환경이기 때문에 실제 환경과 비슷한 데이터나 동작 검증에 적합한 데이터를 얻기 어렵다. 이러한 HIL에서의 문제를 해결하기 위해 외부 센서를 실제 환경에서 사용한 로그나 테스트 환경에서 센서 검증에 사용한 로그를 이용할 수 있다. 본 논문에서 제안하는 외부 센서의 로그를 활용한 HIL 시뮬레이션 기법 확장 내용은 외부 센서 데이터 입력기가 로그로부터 얻은 센서 데이터를 비행 컨트롤러로 보내 검증을 수행하기 때문에 데이터를 재사용할 수 있고 테스트 비용을 줄일 수 있다. 또 외부 센서 데이터 입력기는 로그 파서, 뷰어, 슬라이서, 데이터 전송기로 구성되어 로그로부터 검증에 적합한 데이터를 쉽게 얻어 활용할 수 있다.

• The Journal of Korea Robotics Society
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• v.14 no.4
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• pp.318-325
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• 2019

NREX, an upper limb exoskeleton robot, was developed at the National Rehabilitation Center to assist in the upper limb movements of subjects with weak muscular strength and control ability of the upper limbs, such as those with hemiplegia. For the free movement of the shoulder of the existing NREX, three passive joints were added, which improved its wearability. For the flexion/extension movement and internal/external rotation movement of the shoulder of the robot, the ball lock pin is used to fix or rotate the passive joint. The force and torque between a human and a robot were measured and analyzed in a reaching movement for four targets using a six-axis force/torque sensor for 20 able-bodied subjects. The addition of two passive joints to allow the user to rotate the shoulder can confirm that the average force of the upper limb must be 31.6% less and the torque must be 48.9% less to perform the movement related to the axis of rotation.

• Composites Research
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• v.33 no.4
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• pp.228-233
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• 2020

In this paper, a single lap shear test was performed using a glass fiber reinforced composite material (GFRC). Pencil lead drawn paper sensor (PLDPS) was applied for single lap shear test being performed. Bisphenol-A epoxy and amine hardener were used as adhesives combining with composite materials. To make a difference in adhesive properties, the adhesive was cured under different conditions. PLDPS was made of a 4B pencil on A4 paper. Because graphite in a pencil was an electrically conductive substance, electric resistance (ER) could be measured. A change in ER was observed by a position where a PLDPS was attached to single lap shear specimens. It was confirmed that the change in ER was different depending on two attached positions and was observed by lap shear strain as well. In case the lap shear strain was large, the change in ER of PLDPS was high. This was because the larger the extension of the adhesive part, the larger the degree of bending of the specimen and thus the larger the distance change between two electrodes.

• Journal of the Korean Association of Geographic Information Studies
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• v.6 no.3
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• pp.61-72
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• 2003

Recently, demands with practical applications using high resolution imagery are increasing, according to addressing new sensor data. Since late 1990s, attempts for application to transportation problems of satellite imagery data have been intensively carried out in US, and these kinds of studies are being categorized into the name of RS-T(remote sensing in transportation). Further, this study is also linked with GIS-T(GIS for transportation), being in the matured stage, and then it contributes to wide uses of remotely sensed imagery. In this study, RS-T is briefly summarized. Later, in order to apply urban transportation analysis with satellite imagery as ancillary data, implementation, as prototyped extension program, for extraction of gravity-typed accessibility indices of transportation geography is performed in the ArcView-GIS environment. It is thought that applied results by two models among implemented models in this study can be utilized to characterize transportation accessibility in a region and to apply as useful statistics related to urban transportation status for regional transportation planning, if time series data are used.