• Proceedings of the KSRS Conference
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• 2007.10a
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• pp.374-377
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• 2007

Dual-channel Radiometers for Earth and Atmosphere Monitoring (DREAM) was developed as the Korean first spaceborne microwave radiometer for earth remote sensing. It is the main payload of the Science and Technology SATellite-2 (STSAT-2). STSAT-2 will be launched by Korea Space Launch Vehic1e-l (KSLV-1) at NARO Space Center in Korea in 2008. The DREAM is a two-channel, total power microwave radiometers with the center frequencies of 23.8 GHz and 37 GHz. The bandwidths of radiometer are 600 MHz at 23.8 GHz and 1000 MHz at 37 GHz. The integration time is 200 ms and the required sensitivity is less than 0.5 K. In this paper, we summarize the specification and performance of the developed DREAM firstly. And we describe system integration and performance test of DREAM mounted on spacecraft.

• Advances in aircraft and spacecraft science
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• v.7 no.6
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• pp.553-570
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• 2020

To address the problems caused by the strong coupling of an airbreathing hypersonic vehicle's airframe and propulsion to the integrated control system design, an integrated airframe-propulsion model is established, and the coupling characteristics between the aircraft and engine are analyzed. First, the airframe-propulsion integration model is established based on the typical nonlinear longitudinal dynamical model of an air-breathing hypersonic vehicle and the one-dimensional dual-mode scramjet model. Thrust, moment, angle of attack, altitude, and velocity are used as transfer variables between the aircraft model and the engine model. The one-dimensional scramjet model can accurately reflect the working state of the engine and provide data to support the coupling analysis. Second, owing to the static instability of the aircraft model, the linear quadratic regulator (LQR) controller of the aircraft is designed to ensure attitude stability and height tracking. Finally, the coupling relationship between the aircraft and the engine is revealed through simulation examples. The interaction between vehicle attitude and engine working condition is analyzed, and the influence of vehicle attitude on engine safety is considered. When the engine is in a critical working state, the attitude change of the aircraft will not affect the engine safety without considering coupling, whereas when coupling is considered, the attitude change of the aircraft may cause the engine unstart, which demonstrates the significance of considering coupling characteristics.

• Applied Microscopy
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• v.41 no.3
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• pp.147-154
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• 2011

Backscattered electrons (BSE) are generated at the impact of the primary electron beam on the specimen. BSE imaging provides the compositional contrast to resolve chemical features of sectioned block-face. A focused ion beam (FIB) column can be combined with a field emission scanning electron microscope (FESEM) to ensure a dual (or cross)-beam system (FIB-FESEM). Due to the milling of the specimen material by 10 to 100 nm with the gallium ion beam, FIB-FESEM allows the serial block-face (SBF) imaging of plastic-embedded specimens with high z-axis resolution. After contrast inversion, BSE images are similar to transmitted electron images by transmission electron microscopy. As another means of SBF imaging, a specialized ultramirotome has been incorporated into the specimen chamber of FESEM ($3View^{(R)}$). Internal structures of plastic-embedded specimens can be serially revealed and analyzed by $3View^{(R)}$ with a large field of view to facilitate three-dimensional reconstruction. These two SBF approaches by FESEM can be employed to unravel spatial association of (sub)cellular entities for a comprehensive understanding of complex biological systems.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.29 no.1
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• pp.161-173
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• 1999

This study was performed to compare the bone mineral densities measured at mandibular premolar area by copper-equivalent image and hydroxyapatite phantom with those measured at radius by dual energy absorptiometry and to evaluate the clinical usefulness of Digital system with slide scanner, copper-equivalent image, and hydroxyapatite phantom. For experiment. intraoral radiograms of 15 normal subjects ranged from 20 years old to 67 old were taken with copper-step wedge at mandibular premolar area and bone mineral densities calculated by conversion equation to bone mineral density of hydroxyapatite were compared with those measured at radius distal 1/3 area by Hologic QDR-1000. Obtained results as follows: 1) The conversion equation was Y=5.97X-0.25 and its determination coefficient was 0.9967. The coefficient of variation in the measurement of copper-equivalent value ranged from 4％ to 8％ and showed high reproducibility. 2) The coefficient of variation in the measurement of bone mineral density by the equation ranged from 7％ to 8％ and showed high reproducibility. 3) The bone mineral densities ranged from 0.35 to 0.79g/cm2 at mandibular premolararea. 4) The correlation coefficient between bone mineral densities at mandibular premolar area and those at radius distal 1/3 area was 0.8965. As summary, digital image analyzing system using copper-equivalent image and hydroxyapatite phantom appeared to be clinically useful to measure the bone mineral density at dental area.

• Korean Journal of Social Welfare
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• v.62 no.1
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• pp.391-415
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• 2010

Recently, there were some welfare embezzlement cases of public social workers. The purpose of this study is to explore public perceptions of public social workers by analysing the comments named "datgeul" in the internet media discussion rooms("toronbang") about welfare embezzlement cases of public social workers. The results show that the main discourse about public social workers to perform a dual role as the public servants and social workers on the front line of public social welfare is that they are the victims of both a public official system and welfare administration system. In addition, social workers in public sphere are still recognized as service personnels with sacrifice and commitment rather than as professionals. Finally, the implications of this study were discussed to improve public perceptions of social welfare professionals.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2001.05a
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• pp.237-246
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• 2001

In this paper we introduce a solution to improve the unfairness problem and to remove the waste of bandwidth in the distributed queue dual bus system. This solution requires only a minor modification of the current protocol and further shows no bandwidth wastes when we try to resolve the unfairness problem occurred in current DQDB protocol. There has been many problem in DQDB system in terms of fairness of sending message in each node. In order to solve this problem, Bandwidth Balancing technic and proportional assignment technic have been introduced. It is, however, to note that the waste of bandwidth problem is still existing in those technics, even though there has been significant improvement as to the fairness problem. In this paper we introduce a new solution to remove the waste of bandwidth problem while we are still obtaining the improved fairness of the network. By following this new solution, the simulation result shows higher throughput and lower message delay than previously proposed technics.

• The Journal of Korean Medicine
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• v.33 no.4
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• pp.17-25
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• 2012

Objectives: This study was conducted to explore the contemporary perception of traditional Korean medical doctors (TKMDs) on traditional Korean medicine (TKM) policies and issues. Methods: A questionnaire that included traditional medicine policy- and treatment-related issues was sent to 130 TKM medical centers and 4,300 TKM local clinical offices in Korea, and received responses from total 648 TKMDs in 122 TKM medical centers and 465 TKM local clinical offices. Results: Of the responding TKMDs, 40% believed that unification of Western and traditional medicines would benefit both modes of medical treatment, 67.6% were against allowing Chinese doctor certification to be effective in Korea through the Korea-China FTA (Free Trade Agreement), and 57.8% believed that the number of TKMDs should be reduced. We also found that 46.1% of TKMDs believed that more lectures on Western medicine would be needed in schools of TKM. Moreover, 87.5% of respondents regarded medical knowledge as necessary for treatment, and 49.4% believed National Certification Commission for Acupuncture and Traditional Medicine (NCCAOM) would be not necessary. TKMDs regarded governmental efforts as more vital than education in schools or individual efforts for enhancement of the traditional medical care market in Korea. To efficiently provide the advantages of complementary CAM, such as cost and safety, detailed research is required when policy is made. Conclusions: The TKM industry must implement policies how the relationship with Western medicine can be better defined under the current dual medical system. On the issue of human resources, more research will be needed on the current policy, which serves to maintain the status quo by blocking the importation of Chinese practitioners and by reducing the number of new practitioners.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.4
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• pp.229-237
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• 2013

As demand for IT services increase, which are based on SOA and cloud computing, service level agreements (SLAs) have received more attention in the parties concerned. An SLA is usually a paper contract written in natural language. SLA management tools which are commercially available, implement SLAs implicitly in the application with a procedural language. This makes automation of SLA management difficult. It is also laborious to maintain contract management systems because changes in a contract give rise to extensive modifications in the source code. We see the source of the trouble is the existence of documentary SLAs (paper contracts) and corresponding executable SLAs (contracts coded in the procedural language). In this paper, to resolve the current SLA management problems we propose an active SLM (Active Service Level Management) system, which is based on the active SLA (Active Service Level Agreement). In the proposed system, the separated management and processing of dual SLAs can be unified into a single process with the introduction of active SLAs (ASLAs).

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.45 no.2
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• pp.13-18
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• 2008

In this paper, we consider an amplifying-and-forward(AF) dual-hop relaying system where the source node transmits to a destination node with the help of R relay nodes. We assume that the source node equips M transmit antennas, but only one antenna is equipped at the each node of relay and destination. The outage probabilities are presented when the transmit maximum-ratio-combining(MRC) is used at the source-relay(S-R) links, and the best relay selection, which selects only one relay that contributes the most to the received signal-to-noise ratio(SNR) as active relay, is combined. Simulation results validate these analytical results.

• The Transactions of the Korea Information Processing Society
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• v.1 no.1
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• pp.105-113
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• 1994

This paper introduces the Parallel Advanced Loosely coupled Multiprocessor (PALM) architecture, which is based on HCH(m,p), where m is number of links per a communication processor (CP) and p is the number of application processors (APs) connected to the CP. communication links between a pair of CPs and/or between a CP and an AP, are made of dual-Port RAMs, which provide fast and reliable word-parallel communication between processors. Among the wide spectrum of HCH networks, HCH(m,2) is also known to be a cost optimal topology, such that HCH(m,2) consists of the largest number of APs retaining the minimal number of CPs and communication links. We also implement a testbed based on HCH(2,2). The experiment result shows that the small communication/computation ratio of the PALM system would realize fine-grain parallelism on message-passing MIMD systems.