• Journal of the Korean Institute of Telematics and Electronics
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• v.16 no.6
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• pp.16-21
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• 1979

Two dimensional kernels which reconstruct a tomographic image from a blurred one formed by simple back-projection are investigated in the frequency domain and their performances are compared. The kernels are derived from a point spread function of the tomographic system and have the form of a ramp filter modified by several window functions to suppress ringings or artifacts in the reconstruction. Computer simulation using computer-generated phantom image data with different filter functions has been carried out. In this simulation, it is found that the computation time for 2-D reconstruction is much less than that of 1-D convolution method by a factor of ten or more whereas the reconstructed image quality of the former is far poorer than the latter. In 2-D reconstruction heavy windowing results in less noisy reconstruction but details smear out in this case. The trade-offs between these points are considered.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.4
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• pp.10-17
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• 2014

This paper presents an analytical method for finding the optimum transmission range in mobile ad hoc networks(MANETs). The results are particularly useful for the operation of military networks, as the transmission range affects the traffic throughput of user & routing traffic, delay, and frequency interference. When the conditions of tactical environment are applied in our simulations and the above-mentioned performances are analyzed, we find the OLSR protocol is more excellent. Plus, we compare the results of MANETs performance when applying optimum transmission range and the default transmission range(10km), and analyze the reasonability of the calculation of optimum transmission range proposed by this paper.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.16 no.2
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• pp.23-35
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• 2017

Work zone traffic control is of keen interest because both traffic operations and safety performances are directly affected by traffic management methods. In particular, work zone traffic on two-lane roads needs to be managed in more efficient and safer manners due to its unique characteristics of alternative right-of-way assignment. This study developed a dynamic control algorithm that can be used for real-time operations of two-lane work zone traffic. The performance of the developed algorithm was evaluated by VISSIM microscopic traffic simulator. An applied programming interface (API) based program was developed to plug-in the control algorithm onto the simulator. The results demonstrated the feasibility of the proposed control algorithm for two-lane work zone.

• Journal of Hydrogen and New Energy
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• v.20 no.4
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• pp.300-308
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• 2009

In a pursuit of the development of alternative mobile power sources with a high energy density, a planar and air-breathing PEMFCs with a new type of hydrogen cartridge which uses onsite $H_2$ generated from sodium borohydride ($NaBH_4$) hydrolysis have been investigated for use in advanced power systems. Two types of $H_2$ generation through $NaBH_4$ hydrolysis are available: (1) using organic acids such as sulphuric acid, malic acid, and sodium hydrogen carbonate in aqueous solution with solid $NaBH_4$ and (2) using solid selected catalysts such as Pt, Ru, CoB into the stabilized alkaline $NaBH_4$ solution. It might therefore be relevant at this stage to evaluate the relative competitiveness of the two methods mentioned above. The effects of flow rate of stabilized $NaBH_4$ solution, MEA (Membrane Electrode Assembly) improvement, and type and flow control of the catalytic acidic solution have been studied and the cell performances of the planar, air-breathing PEMFCs using $NaBH_4$ has been measured from aspects of power density, fuel efficiency, energy density, and fast response of cell. In our experiments, planar, air-breathing PEMFCs using $NaBH_4$ achieved to maximum power density of 128mW/$cm^2$ at 0.7V and energy efficiency of 46% and has many advantages such as low operating temperature, sustained operation at a high power density, compactness, the potential for low cost and volume, long stack life, fast star-up and suitability for discontinuous operation.

• Journal of Information Display
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• v.6 no.3
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• pp.18-21
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• 2005

A new technology for reducing photolithography process from a four step to a three step process in the fabrication of TFT LCD is introduced. The core technology for 3-mask-TFT processes is the lift-off process [1], by which the PAS and PXL layers can be formed simultaneously. A different method of the lift-off process was developed in order to enhance the performance of efficiency with conventional positive and not negative PR which is the generally used in other lift-off process. In addition, the removal capacity of the ITO/PR in lift-off process was evaluated. The evaluation results showed that the new process can be run in conventional TFT production condition. In order to apply this new process in existing TFT process, several tests were conducted to ensure stability of the TFT process. It was found that the outgases from PR on the substrate in ITO sputtering chamber do not raise any problem, and the deposited ITO film beside the PR has conventional ITO qualities. Furthemore, the particles that were produced due to the ITO chips in PR strip bath could be reduced by the existing filtering system of stripper. With the development of total process and design of the structure for TFT using this technology, 3-mask-panels were achieved in TN and IPS modes, which showed the same display performances as those with the conventional 4mask process. The applicability and usefulness of the 3-mask process has already verified in the mass production line and in fact it currently being used for the production of some products.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.18 no.6
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• pp.191-201
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• 2019

A fast and accurate integrated traffic object detection framework was proposed and developed, harnessing a computer-vision based deep-learning approach performing automatic object detections, a multi object tracking technology, and video pre-processing tools. The proposed method is capable of detecting traffic object such as autos, buses, trucks and vans from video recordings taken under a various kinds of external conditions such as stability of video, weather conditions, video angles, and counting the objects by tracking them on a real-time basis. By creating plausible experimental scenarios dealing with various conditions that likely affect video quality, it is discovered that the proposed method achieves outstanding performances except for the cases of rain and snow, thereby resulting in 98% ~ 100% of accuracy.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.15 no.2
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• pp.152-159
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• 2004

Objective : The present study investigated the interpretation bias and expectation and judgemental bias of performance in socially anxious children. Method : Children with high social anxiety (n=18) and low social anxiety (n=16) were recruited through self-report and peer nomination, Participants performed three tasks to assess for cognitive bias. The first task measured interpretation of ambiguous social situations. The second task measured expectations regarding performance in a three minute impromptu speech. The third task assessed for judgemental bias via comparison between post-speech self rating and observer rating. Result : Children with high social anxiety did not differ significantly from low social anxiety children on the dependent measures assessing bias in interpretation, expectation and judgement. However, a significant difference was found in the judges' rating of children's performances on the speech task, with high social anxiety children obtaining significantly lower scores compared to low social anxiety children. Conclusion : The role of cognitive biases in the development and maintenance of social anxiety in children was discussed.

• 한국HCI학회:학술대회논문집
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• 2008.02b
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• pp.103-108
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• 2008

Art is an ongoing process of experimenting and challenging. The challenge and experiments of the artists encompass both the conceptual process and the expressive process of creating artworks. It is not mandatory to use cutting-edge technologies for interactive performances, since they can be realized by adapting pre-existing technologies. Using previous technologies reduces the difficulties in the production process and makes it easier for the audience to understand the way of participation. In this paper, propose an ARS-server-based control system in which a large audience can participate during a performance to control certain features on stage. This system was first proposed during the 'Ubiplay Workshop and Seminar' hosted by the GSCT, KAIST, and applied to the digital performance 'Syntasia' in June and July, 2007, hosted by the Goyang Culture Foundation.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.668-672
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• 2003

In order to reach the high electrical quality of organic thin film transistors (OTFTs) such as high mobility and on-off current ratio, it is strongly desirable to study the enhancement of electrical properties in OTFTs. Here, we report the novel method of hydrogen $(H_{2})$ plasma treatment to improve electrical properties in inverted staggered OTFTs based on pentacene as active layer. To certify the effect of this method, we compared the electrical properties of normal device as a reference with those of device using the novel method. In result, the normal device as a reference making no use of this method exhibited a field effect mobility of 0.055 $cm^{2}/Vs$, on/off current ratio of $10^{3}$, threshold voltage of -4.5 V, and subthreshold slope of 7.6 V/dec. While the device using the novel method exhibited a field effect mobility of 0.174 $cm^{2}/Vs$, on/off current ratio of $10^{6}$. threshold voltage of -0.5 V, and subthreshold slope of 1.49 V/dec. According to these results, we have found the electrical performances in inverted staggered pentacene TFT owing to this novel method are remarkably enhanced. So, this method plays a key role in highly improving the electric performance of OTFTs. Moreover, this method is the first time yet reported for any OTFTs

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.48 no.6
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• pp.9-16
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• 2011

Due to the development and proliferation of ubiquitous technologies and services, various sensor network applications are being appeared on the stage. The needs for algorithms requiring sensor data fusion and complex signal processing with a high-performance processor such as a digital signal processor are also increased. However, it is difficult to use such processor for the low-power sensor network operating with a battery because of power consumption. This paper proposes a hybrid-type sensor module architecture supporting wakeup/sleep software framework for the wireless sensor node and shows the implemented sensor node platform and performances focused on the energy consumption and wakeup time.