• Journal of the Institute of Electronics Engineers of Korea TE
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• v.37 no.2
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• pp.83-90
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• 2000

A simple low-cost and small size 1.88-198 GHz Band RF power amplifier module is developed for IMT2000 repeater. The power amplifier consists of two stage amplifiers that the first stage amplifier is drive amplifier using discrete type P-HEMT (ATF-34143, 800 micron gate width, Agilent Technologies) and the second is power amplifier with 300Bm 1dB gain compression point using GaAs FET(EFA240D-SOT89, 2400 micron gate width, Excelics Semiconductor). this power amplifier module feature a 29.5dBm 1dB gain compression point, 29.5dB gain, 42dBm 3rd order intercept point(OIP3) and -10dB/-l2dB input/output return loss over the 1880-1980 MHz. This PA module is fully integrated using MIC technology into a small size and design by full nonlinear design technologies. The dimensions of this PA module are 42(L) $\times$ 34(W) mm.

• Asian-Australasian Journal of Animal Sciences
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• v.10 no.6
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• pp.614-620
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• 1997

Pedigree data were used to predict the performance of 1,166 imported Americas Brahman breeder cattle, composed of 104 bulls and 1,062 heifers with an average age of 24.4 months (range of 17 to 40 months). A total of 13 full sib, 10 maternal half sib, and 228 paternal half sib groups were identified, each with average group size of 2.08, 2.00, and 4.49, respectively. Only 758 (64.9% of total) imported cattle were found to have at least one ancestor with expected progeny differences (EPDs) reported in the Spring 1995 Brahman Sire Summary. Moderate average accuracy values of .71, .69, .52, and .52 for birth weight, weaning weight, yearling weight, and maternal milk, respectively, were noted for EPDs of the ancestors. Prediction equations were derived by multiple regression analysis of available EPDs of sire, paternal grand sire, and maternal grand sire. Based on pedigree indexes that involve various combinations of available ancestral information, the average predicted EPDs (lbs) for imported cattle were $1.76{\pm}0.54$, $14.93{\pm}4.86$, $25.10{\pm}9.50$, and $5.86{\pm}2.08$ for birth weight, weaning weight, yearling weight, and maternal milk, respectively. Significant correlations (p < .05) were also found between sire and son EPDs (+.27) for yearling weight; and between sire and paternal grand sire EPDs for birth weight (+.34), weaning weight (+.51), yearling weight (+.49), and maternal milk (+.55).

• Geophysics and Geophysical Exploration
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• v.15 no.4
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• pp.219-226
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• 2012

This study provides an analysis on results of neutron logging for various borehole environments through numerical simulation based on a Monte Carlo N-Particle (MCNP) code developed and maintained by Los Alamos National Laboratory. MCNP is suitable for the simulation of neutron logging since the algorithm can simulate transport of nuclear particles in three-dimensional geometry. Rather than simulating a specific tool of a particular service company between many commercial neutron tools, we have constructed a generic thermal neutron tool characterizing commercial tools. This study makes calibration chart of the neutron logging tool for materials (e.g., limestone, sandstone and dolomite) with various porosities. Further, we provides correction charts for the generic neutron logging tool to analyze responses of the tool under various borehole conditions by considering brine-filled borehole fluid and void water, and presence of borehole fluid.

• Safety and Health at Work
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• v.3 no.2
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• pp.140-145
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• 2012

Objectives: To understand the personal experiences of mine workers that have experienced job relocation due to silicosis at the Andina Division of Corporaci$\acute{o}$n Nacional del Cobre (CODELCO), Chile. The purpose of the study was to provide useful information for the development of new local, business and public policies for the care of workers with silicosis. Methods: A qualitative study based on a practical case study of 5 workers. The information was collected by means of structured individual interviews. The method of analysis was phenomenology. Results: The corporal axis was the most commented upon. It included awareness of the illness, body pains, fatigue, and antagonistic mood disorders (sadness, or the difficulty in finding meaning in life). As far as personal relationships, there was evidence of strong relationships with family, coworkers and friends, as well as extended family. Over all, the experience of relocation was positive with periods of impatience and uncertainty. The job reassignment provided a new and pleasant context for the relocated workers and in the process improved their perception of their quality of life. Conclusions: A multidisciplinary team should attend mine workers relocated because of silicosis by addressing the mental and physical aspects of their disease, along with the integral participation of close family members. It is suggested that this investigation be maintain over time to record the personal experiences in the medium-term, adding new cases with the intention of shedding more light on the phenomenon being studied. As a preventive measure, continual workshops are needed on the proper use of respiratory protection in addition, a group of monitors is required.

• International Journal of Concrete Structures and Materials
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• v.11 no.1
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• pp.59-68
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• 2017

Mercury intrusion and nitrogen sorption porosimetry were employed to investigate the pore structure of calcium sulfoaluminate ($C{\bar{S}}A$) and portland cement pastes with cement-to-water ratio (w/c) of 0.40, 0.50, and 0.60. A unimodal distribution of pore size was drawn for $C{\bar{S}}A$ cement pastes, whereas a bimodal distribution was established for the portland cement pastes through analysis of mercury intrusion porosimetry. For the experimental results generated by nitrogen sorption porosimetry, the $C{\bar{S}}A$ cement pastes have a smaller and coarser pore volume than cement paste samples under the same w/c condition. The relative dynamic modulus and percentage weight loss were used for investigation of the concrete durability in freeze-thaw condition. When coarse aggregate with good freeze-thaw durability was mixed, air entrained portland cement concrete has the same durability in terms of relative dynamic modulus as $C{\bar{S}}A$ cement concrete in a freeze-thaw environment. The $C{\bar{S}}A$ cement concrete with poor performance of durability in a freeze-thaw environment demonstrates the improved durability by 300 % over portland cement concrete. The $C{\bar{S}}A$ concrete with good performance aggregate also exhibits less surface scaling in a freeze-thaw environment, losing 11 % less mass after 297 cycles.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.11 s.114
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• pp.1058-1064
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• 2006

In this paper, the channel capacity of a specified wireless indoor multiple-input multiple-output(MIMO) channel is estimated by analyzing spatial characteristics of this channel using the three-dimensional ray tracing method, and a technique for deriving an optimized separation of multi-antenna elements is proposed. At first, the ray paths, the path losses, and the time-delay profile are computed using the three-dimensional ray tracing method in an indoor corridor environment, which has the line of sight(LOS) and non-line of sight(NLOS) regions. The ray tracing method is verified by a comparison between the computation results and the measurements which are obtained with dipole antennas, an amplifier and a network analyzer. Then, an MIMO system is positioned in the indoor channel environment and the ray paths and path losses are computed for four antenna-position combinations and various values of the antenna separation to obtain the channel capacity for the MIMO system. An optimum antenna-separation is derived by averaging the channel capacities of 100 receiver positions with four different antenna combinations.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37C no.10
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• pp.965-976
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• 2012

Multi-Platform Image and Intelligence Common data link(MPI-CDL) systems are designed to transmit the imaginary and signal intelligence data at an aeronautical to ground line of sight(LOS) link. This paper proposes a method to predict a link availability and analyzes the required link margin to satisfy a given link availability for MPI-CDL systems. To estimate a link availability the proposed method applies the conditional probability so that both a rain attenuation and a multipath fading are considered simultaneously. Link margins to meet the link availability for MPI-CDL systems are calculated according to an operating environment including frequencies, flight altitudes and transmission ranges. The required link margins for actual unmanned air vehicle systems are also given by simulation results.

• Clinics in Shoulder and Elbow
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• v.19 no.1
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• pp.25-32
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• 2016

Background: The goal of this study was to evaluate whether a modified fluoroscopic technique for positioning a hook plate affected the clinical results of treating Neer type II distal clavicle fractures and Rockwood type V acromioclavicular (AC) joint separations with this device. Methods: The study was a retrospective consecutive case series with data analysis. Sixty-four patients with a Neer type II distal clavicle fracture or a Rockwood type V AC joint injury treated between March 2009 and June 2013 were divided into 2 groups: traditional fluoroscopic technique (traditional view, 31 patients) or modified fluoroscopic technique ('hook' view, 33 patients). A visual analogue scale (VAS) score, the modified University of California-Los Angeles (UCLA) shoulder scale score, and radiographic osteolysis were the main outcome measures. Results: The traditional group included a significantly larger number of patients with acromial osteolysis than the hook view group: 23 patients (74.2%) vs. 11 patients (33.3%), respectively (p=0.01). Before plate removal, the hook group reported less pain and higher UCLA shoulder scale scores than the traditional group: average VAS score, 1.55 vs. 2.26, respectively; average UCLA score, 30.88 vs. 27.06, respectively. However, there was no significant difference after plate removal. Conclusions: The hook view allows more accurate bending of the hook plate around the contour of the acromion, resulting in decreased osteolysis, decreased pain, and better function with the plate in situ.

• Journal of the Korean Society of Hazard Mitigation
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• v.8 no.1
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• pp.31-37
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• 2008

Traffic flow which is prescribed under previous traffic effect/access act is analyzed by traffic volume, V/C, mean speed on road and LOS on the intersection. These indexes based on analytical method can not consider stochastic characteristics of traffic flow. Moreover it is hard to analyze traffic flow visually in whole traffic effect area because only individual road and intersections are targeted. In this study, it is devised to show traffic flow analysis method within traffic effect area visually applying microscopic-simulation by car-following theory, and then based on this, effect analyze ways are studied according to space range plan, improvement measure establishment and etc. To execute this study, effect area is set up using V/C, and the change of traffic current around development area is analyzed using microscopic-simulation program.

• Journal of Navigation and Port Research
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• v.37 no.6
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• pp.587-595
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• 2013

Establishment and operation of Aids to Navigation in the process of port design, construction and management are crucial factor of maritime safety and collision prevention. According to the IMO SOLAS Chapter 5, regulation 13, the establishment and operation of maritime safety facilities are mandated for the competent authorities. The facilities of Aids to Navigations are moving to a concept of e-Navigation with state-of-the-art technology of radio navigation equipments such as AIS, DGPS and e-Loran from the traditional visual facilities (optics, shape), Although the autonomous maritime traffic system is a new trend, yet the traditional and conventional Aids to Navigation like lighthouses and beacons are still imperative for vessel's safe navigation. In this paper, for decision of service level of maritime traffic facilities to enhance the efficiency of visual navigation system management it was proposed the Aids to Navigation availability as an efficient management system incorporating the whole maritime traffic facilities under one management system. Comparison of foreign level of services and analysis of the theoretical background of them were analyzed and the proposed LOS was applied to Incheon area to evaluate the safety of navigation routes.