• Journal of Satellite, Information and Communications
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• v.10 no.3
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• pp.109-113
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• 2015

This paper presents the study results on a dual band feed horn for the focused reflector. A coaxial waveguide structure is attractive to avoid blockage from the feeder. The inner conductor as a hollow waveguide is designed to excite TE11 of a circular waveguide for high frequency. For low frequency, the design of the outer coaxial waveguide that propagates coaxial TE11 and prevents fundamental TEM is presented. The horn size for generation of these modes results in the degradation of performance. The return loss is improved by a capacitive iris and an inductive iris The enhanced pattern symmetry by dual mode is presented. The horn design in this paper are verified through the test.

• Convergence Security Journal
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• v.6 no.3
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• pp.37-47
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• 2006

In this research, We connect the terrestrial magnetism sensor of the Philips to a bluetooth communication system and measured 360 degree of the azimuth change the angle with an incline of 5 degrees to an order direction. The value of the azimuth to be measured sent to the Bluetooth communication system and analyzed the measuring value in the 100m as moved. Using the bluetooth, we could send the measuring value of the azimuth without the bearing error in the plain without an electric wave obstacle within a distance in straight line 100M. We got the value of the azimuth have 98% reliability to maintain at a level with the terrestrial magnetism sensor. Based on this research. We send the measuring value of the azimuth which the accuracy is improved to a mobile intelligent robot moving a land inclined equipped with this system and can track the azimuth of it.

• The KIPS Transactions:PartC
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• v.11C no.7 s.96
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• pp.993-998
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• 2004

As Worm Virus & DDoS attack appeares, the targets and damage of infringement accidents are extending from specific system or services to paralysis of the network itself. These attacks are expending very frequently and strongly, and ISP who will be used as the path of these attacks will face serious damages. But compare to Worm Virus & DDoS attack that generally occures in many Systems at one time with it's fast propagation velocity, network dimensional opposition is slow and disable to deal with the whole appearance for it is operated manually by the network manager. Therefore, this treatise present devices how to detect Worm Virus & DDoS attack's outbreak and the attacker(attacker IP adderss) automatically.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.2
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• pp.247-252
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• 2015

Adaptive algorithms based on the criterion of zero-error probability (ZEP) have robustness to impulsive noise and their decision feedback (DF) versions are known to compensate effectively for severe multipath channel distortions. However the ZEP-DF algorithm computes several summation operations at each iteration time for each filter section and this plays an obstacle role in practical implementation. In this paper, the ZEP-DF with recursive gradient estimation (RGE) method is proposed and shown to reduce the computational burden of O(N) to a constant which is independent of the sample size N. Also the weight update of the initial state and the steady state is a continuous process without bringing about any propagation of gradient estimation error in DF structure.

• Journal of the Korea Society for Simulation
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• v.27 no.4
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• pp.27-45
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• 2018

The terrestrial communication network and the underwater acoustic communication network have very different communication characteristics each other in operational environments, communication media, propagation delay, frequency bandwidth, transmission speed, bit error rate, and so on. These different characteristics cause some different address schemes and different maximum transmission units and, as a result, these differences must form certainly obstacles to the intercommunication between a terrestrial communication network and an underwater acoustic communication network. In this paper, we presents a method to use the virtual addresses to resolve the interconnection problem caused by different address schemes between a terrestrial communication network and an underwater acoustic communication network, and, through a mathematical modeling, we analyze the performance on the message transceiving delay time in the underwater environment.

• Korean Journal of Psychosomatic Medicine
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• v.22 no.1
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• pp.31-39
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• 2014

Objectives : This study aimed to investigate the psychiatric status of HIV-infected/AIDS inpatients in a general hospital over the past 2.5 years. Methods : A retrospective chart review was conducted of psychiatric consultations performed between January 1, 2011, and July 30, 2013. The records of 97 HIV-infected/AIDS patients were analyzed. These included a total of 282 psychiatric consultations. Results : Of the 97 patients, 91(93.8%) were male, the mean age was 48 years, and mean number of consultations was 2.8. Depressed mood was reported in 102 consultations(23.8%), insomnia in 60(14.0%), and anxiety in 31(7.2%). Psychiatric disorders diagnosed on initial consultation included depressive disorder(37 patients ; 37.0%), cognitive disorder(11 ; 11.0%), and delirium(9 ; 9.0%). Recommended psychotropic medication included Lorazepam(99 ; 17.2%), Escitalopram(90 ; 15.7%), and Quetiapine(84 ; 14.6%). Conclusions : The main complaints of HIV-infected/AIDS patients were depressed mood, insomnia, and suicidal ideation(including suicide attempts). In total, 85(93.3%) patients of those consulted were diagnosed as meeting the criteria for a psychiatric condition. However, considering that only 16.9% of patients consulted received follow-up treatment, longitudinal research is needed to examine the influence of psychiatric disorders on the transmission of HIV-infection/AIDS, as well as on prognosis and treatment adherence.

• KEPCO Journal on Electric Power and Energy
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• v.5 no.3
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• pp.149-156
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• 2019

In the field of maintenance of power transmission lines, drones have been used for their patrol and inspection by KEPCO since 2017. This drone technology was originally developed by KEPCO Research Institute, and now workers from four regional offices of KEPCO have directly applied this technology to the drone patrol and inspection tasks. In the drone inspection system, a drone with an optical zooming camera and a thermal camera can fly automatically along the transmission lines by the ground control system developed by KEPCO Research Institute, but its camera gimbal has been remotely controlled by a field worker. Especially the drone patrol and inspection has been mainly applied for the transmission lines in the inaccessible areas such as regions with river-crossings, sea-crossings and mountains. There are often communication disruptions between the drone and its remote controller in such extreme fields of mountain areas with many barriers. This problem may cause the camera gimbal be out of control, even though the inspection drone flies along the flight path well. In addition, interference with the reception of real-time transmitted videos makes the field worker unable to operate it. To solve these problems, we have developed the auto-tracking camera gimbal system with deep learning method. The camera gimbal can track the transmission line automatically, even when the transmitted video on a remote controller is intermittently unavailable. To show the effectiveness of our camera gimbal system, its field test results will be presented in this paper.

• Tuberculosis and Respiratory Diseases
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• v.39 no.1
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• pp.55-61
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• 1992

Background: The lung is the most common site of metastasis and usually it manifests as a single or multiple nodules in chest X-ray. But less commonly the cancer spreads through the lymphatics and X-ray shows diffuse reticulonodular densities. Sometimes, patient is presented with respiratory symptoms only with interstitial lung infiltration before the signs of primary tumor and in that cases, the differential diagnosis with other interstitial lung disease is required. We have experienced 5 such cases, who were diagnosed as lymphangitic carcinomatosis by transbronchial lung biopsy. Methods: Clinical manifestation, pulmonary function test, modified thin section CT, bronchoalveolar lavage and transbronchial lung biopsy were done. Results: The primary tumor was gastric cancer in 3, lung cancer in 2. Pulmonary function test showed restrictive pattern with low DLco in 2 patients and obstructive pattern in one. Bronchoalveolar lavage showed lymphocytosis in 4 patients and malignant cells were found in one patient. Transbronchial lung biopsy revealed malignant cells localized to the lymphatics (peribronchial, perivascular and perialveolar). Cell type was adenocarcinoma in 4 and squamous cell carcinoma in one. Conclusion: Rarely lymphangitic carcinomatosis can be presented as diffuse interstitial lung disease and easily diagnosed by transbronchial lung biopsy.

• Journal of Advanced Navigation Technology
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• v.16 no.6
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• pp.935-943
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• 2012

In this paper a three step procedure was derived to select the GNSS network receiving site candidates for GNSS based infrastructure technology development and according to the proposed procedure the 4 site candidates was selected for final network configuration. In the first step, the site requirement was produced for GNSS based infrastructure technology development referring regulation of the international organizations related to permanent GNSS data receiving and the first candidates were selected using the proposed requirement. In the second step, the second candidates were selected among the first candidates by analyzing the visual measurement, environment test and so on. In the third step the final candidates were selected among the second candidates by analyzing sky clearance, radio frequency interference. Through above the three step procedure 16,7,4 candidates of site were selected sequentially and receiving station site could be effectively selected.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.2 no.4
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• pp.643-652
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• 1998

This paper presents the characteristics of a relay station antenna with the newly designed back-plate structure which is composed of the U-shaped metal plate for suppression of the back lobe by edge diffraction. The back lobe level of the conventional type was about -20 dB in the -z direction ( 180 ) . In order to improve the characteristics, the U-shaped mesh type metal plate is considered, where the design condition of the model antenna satisfies the wide null point angle range with the back lobe level of -30 dB below in the -z direction. The design parameters with the minimum back lobe level such as the dipole length, the distance between dipole elements and the back plate size have been found by using the released NEC Win Pro code. The calculated and measured back lobe Bevel of model antenna have been obtained 48.48 dB and -45 dB at 325 MHz, respectively.