• Journal of Advanced Navigation Technology
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• v.16 no.4
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• pp.697-702
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• 2012

With an elevator supply and demand increases, It has been enlarged various requirements for the safety of the elevator. Elevator safety requirements can be the ability to respond to emergencies quickly. Recently, QR code was attached to all elevator for the elevator safety and it is established by law for the Elevator rescue work. And also the elevator system is seeking to utilize more secure elevator with mandatory installation of CCTV and direct call devices. However, CCTV and direct call service is operating on an individual method and it has not been proposed integrated model. In this paper, we propose the safety elevator integration model with CCTV, direct call service and remote control based on smart phone. Using the proposed model, we can be improved the efficiency of maintenance and ability of prompt action in the event of a disaster.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.1
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• pp.88-99
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• 1996

The explicit scheme for finite element analysis of sheet metal forming problems has been widely used for providing practical solutions since it improves the convergency problem, memory size and computational time especially for the case of complicated geometry and large element number. The explicit schemes in general use are based on the elastic-plastic modeling of material requiring large computataion time. In the present work, a basic formulation for rigid-plastic explicit finite element analysis of plain strain sheet metal forming problems has been proposed. The effect of some basic parameters involved in the dynamic analysis has been studied in detail. Thus, the effective ranges of parameters have been proposed for numerical simultion by the rigid-plastic explicit finite element method. A direct trial-and-error method is introduced to treat contact and friction. In computation, sheet material is assumed to possess normal anisotropy and rigid-plastic workhardening characteristics. In order to show the validity and effectiveness of the proposed explicit scheme, computations are carried out for cylindrical punch stretching and the computational results are compared with those by the implicit scheme as well as with a commercial code. The proposed rigid-plastic exlicit finite element method can be used as a robust and efficient computational method for analysis of sheet metal forming.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.4
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• pp.419-424
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• 2019

In this paper, we proposed an algorithm to estimate the desired target in wideband jamming signal environment. In order to suppress the jamming signal, we use the spatial time adaptive algorithm and QR decomposition to obtain the optimal weight. The spatial time adaptive algorithm of adaptive array antenna system multiplies the tap delay signal by a complex weight to obtain a weight. In order to minimize the power consumption because of the inverse matrix, optimal weight is obtained by using QR decomposition. Through simulation, we compare and analyze the performance of the proposed algorithm and the existing algorithm. In the target estimation of [-40o,0o,+40o], the proposed algorithm estimated all three targets, but the existing algorithm estimated only [0o] due to of the jamming signal. We prove that the proposed algorithm improves performance by removing the jamming signal and estimating the target accurately.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.4
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• pp.434-439
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• 2019

This paper proposed a control algorithm to compensate the delay time to improve the signal to noise, and the proposed control algorithm estimate the target information to apply the continuous wave radar equation. The proposed control algorithm improves the output signal of each array element bv multiplying the weight of the receive signal to the signal to noise ratio. Radar radiate a signal in spatial and the target information is estimated by the echoed signal from the target. But the signal in the wireless communication environment occurs the delay time due to the multipath which appear human and natural structures. It is difficult to accurately estimate the desired information because of the degradation for the system performance due to the interference signal and the signal distortion. The target information can be improved by compensating the delay signal to apply the weight to the received signal by using the uniform linear array antenna. As a simulation result, we show that the performance of the proposed control algorithm and the non-compensated delay time are compared. The proposed control algorithm proved that the target distance estimation information is improved.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.14 no.1
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• pp.7-13
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• 2021

This paper proposes a method to minimize the target's direction detection error using RADAR. The radar system cannot accurately detect the target direction due to the phase error of he received signal. The proposed method of this study obtains a phase by applying an root mean square to each antenna incident signal, and reduces the phase error by using an optimal signal to noise ratio. In the simulation result, the probability of detecting the target direction is the best when the antenna spacing is half wavelength. The conventional method of direction detection probability 10-1.7 and the proposed method is 10-3.3. The target detection direction of the existing method represents [-8°,8°] with an error of 2 degrees. The target detection direction of the proposed method is shown in [-10°,10°], and all target directions are accurately detected. In the future, There is need for a method to reduce the phase error even though the resolution decrease.

• Journal of the Korea Convergence Society
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• v.10 no.12
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• pp.293-298
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• 2019

The global market for temperature sensors for power plants is estimated at around 35 billion won, of which South Korea relies on imported products for more than 95 percent. This study is that a temperature measurement device for gas turbine rotators for power plants and can be applied to more than 800 of 100 MW gas turbine generators operating in Korea. This study has improved durability by changing the shape of the measuring part, structure of the connecting part, and material changes, and is a component technology applicable to other measuring devices such as humidity, gas and hydraulic pressure used in precision chemical process and plant export industry. As a result of this study, temperature sensors designed as three types of sensors for measuring the temperature of the gas turbine for power plants met Class 1 temperature accuracy in the range of 0℃ to 300℃, and improved durability significantly compared to similar products.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.2
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• pp.61-66
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• 2020

The purpose of this study is to identify and manage the problem of components discontinuity in the future based on the implementation of information systems to solve the problem of discontinuance of militaries parts, so as to solve the problem of discontinuance of components in the operation of the weapon systems and reduce excessive expenditure due to aging of the weapon system. The purpose is to prevent the discontinuance of components in the future by up-dating the production phenomena of parts manufactures periodically. Defense industries and R&D perood can expand users convenience by supporting selection of more efficient parts in weapon systems development and information of vast components information systems.

• Nuclear Engineering and Technology
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• v.15 no.1
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• pp.33-40
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• 1983

It is shown that the Shanks sequence $E_{k}$-transformation and the conventional extrapolation method are theoretically related. The $E_1$$^2$-transformation method is then applied for the multigroup diffusion problems. The diffusion code, CITATION, is modified for this study and the computing time is compared for each iteration tactics. The Equipose method, in which only sing1e inner iteration for each energy group is carried for an outer iteration, has been known as the fastest iteration method. However, in the case of 3-group problems, the proposed method, in which the number of inner iteration for the fast and thermal group is 2 and 1 respectively, gives better convergency than the Equipose method by about 12%. The double extrapolation method results in faster computing time than the single extrapolation method without computing storage problem. It is, however, to note that this method is verified only for a two-group treatment.t.

• Journal of the Korean Geophysical Society
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• v.10 no.1
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• pp.27-35
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• 2007

There are many risks in constructing tunnel-structure. To prevent these risks from occurring and secure safety, the precise and rapid survey of inside displacement of the tunnel is required. But nowadays the measurement of the crown settlement, convergency, and surface settlement depends on general kinds of method which use total station or level. In the way to provide data about maintaining structure according to recent improvement and progress of measuring technology, 3D laser scanning is used. It solves the problem of reliability in measuring displacement of existing structure, provides material that enables to estimate shape change of structure visually, and makes it possible to deliberate speedy countermeasure. By this three dimensioning it is possible to make efficient use of structure maintenance and field measurement.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.4
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• pp.43-50
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• 2020

The purpose of this study is to examine the case of constructing information and communication facilities in daycare centers and to propose an educational environment that can foster young talents who can lead the era of the fourth industrial revolution. In particular, after COVID19, a method was proposed to create an information and communication environment suitable for children to receive personalized education, and to create an environment for experiential education if possible, and at the same time to enable averaging of customized learning. Since there has been no research on information and communication facilities in daycare centers, we intend to place significance on starting, and in the future, to foster creative and contextual children, we will reduce the movement of teachers through smart speakers and mobile devices, and tailor the educational environment through AI data. I think that the design of the daycare center should be changed in the direction of making the product. To this end, the CM role of information and communication supervision is needed, and it is hoped that it will become a design standard for daycare centers after COVID19 by developing research on daycare centers.