• Journal of KIISE:Information Networking
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• 제36권1호
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• pp.12-23
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• 2009

Sensor networks deployed in battlefields to support military operations or deployed in natural habitats to monitor the rare wildlifes must take account of protection of the location of valuable assets(i.e., soldiers or wildlifes) from an adversary or malicious tracing as well as the security of messages in transit. In this paper we propose a routing protocol GSLP(GPSR-based Source-Location Privacy) that is capable of enhancing the location privacy of an active source node(i.e., message-originating node) in the presence of multiple dormant sources(i.e., nodes lying nearby an asset whose location needs to be secured). Extended is a simple, yet scalable, routing scheme GPSR(greedy perimeter stateless routing) to select randomly a next-hop node with a certain probability for randomizing paths and to perform perimeter routing for detouring dormant sources so that the privacy strength of the active source, defined as safety period, keeps enhanced. The simulation results obtained by increasing the number of dormant sources up to 1.0% of the total number of nodes show that GSLP yields increased and nearly invariant safety periods, while those of PR-SP(Phantom Routing, Single Path), a notable existing protocol for source-location privacy, rapidly drop off as the number of dormant sources increases. It turns out that delivery latencies of GSLP are roughly less than two-fold of the shortest path length between the active source and the destination.

• Journal of Korea Technology Innovation Society
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• 제19권4호
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• pp.799-821
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• 2016

Unmanned Aerial Vehicles (UAVs) are essential systems for Intelligence, Surveillance, and Reconnaissance (ISR) operations in current battlespace. And its importance will be getting extended because of complexity and uncertainty of battlespace. In this study, we forecast the advancement of 96 UAVs during the period of 32 years from 1982 to 2014 using TFDEA. TFDEA is a quantitative technology forecasting method which is characterized as non-parametric and non-statistical mathematical programming. Inman et al. (2006) showed that TFDEA is more accurate in forecasting compared with classical econometrics (e.g. regression). This study got 4.06% point of annual technological rate of change (RoC) for UAVs by applying TFDEA. And most UAVs in the period are inefficient according to the global SOA frontiers. That is because the countries which develop UAVs are in the middle class of technological level, so more than 60% of world UAVs markets are shared by North America and Europe which are advanced countries in terms of technological maturity level. This study could give some insights for UAVs development and its advancement. And also can be used for evaluating the adequacy of Required Operational Capability (ROC) of suggested future systems and managing the progress of Research and Development (R&D).

• The Journal of Korean Institute of Communications and Information Sciences
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• 제33권8C호
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• pp.575-582
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• 2008

In this paper we described the process and the results of real-time implementation of G.729.1 wideband speech codec which is standardized in SG15 of ITU-T. To apply the codec on ARM926EJ-S(R) processor core. we transformed some parts of the codec C program including basic operations and arithmetic functions into assembly language to operate the codec in real-time. G.729.1 is the standard wideband speech codec of ITU-T having variable bit rates of $8{\sim}32kbps$ and inputs quantized 16 bits PCM signal per sample at the rate of 8kHz or 16kHz sampling. This codec is interoperable with the G.729 and G.729A and the bandwidth extended wideband($50{\sim}7,000Hz$) version of existing narrowband($300{\sim}3,400Hz$) codec to enhance voice quality. The implemented G.729.1 wideband speech codec has the complexity of 31.2 MCPS for encoder and 22.8 MCPS for decoder and the execution time of the codec takes 11.5ms total on the target with 6.75ms and 4.76ms respectively. Also this codec was tested bit by bit exactly against all set of test vectors provided by ITU-T and passed all the test vectors. Besides the codec operated well on the Internet phone in real-time.

• Journal of Chest Surgery
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• 제29권3호
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• pp.285-291
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• 1996

We have reviewed 157 cases of coarctation of aorta in the age of infancy and children from March 1973 to december 1994. Patients were 9) males and 64 females, and their age ranged from one month to fifteen years (23.8 $\pm$ 41.6months) with 113 infant cases. In the infantile age, congestive heart failure was the most common chief complaint (781113), and above that age, asymptom was most common (15/44). Isolated coarctation was present in 31 patients, and 9 patients had additional atrial septal defect (group I), 73 patients had associated ventricular septal defect (group II), and 44 patients had associated complex intracardiac lesions(group III). Aortic arch hypoplasia was present in 17 patients. , The operations perf'ormed were subclavian flap angioplasty in 71 patients, resection and anastomosis in 32 patients, patch aortoplasty in 26 patients, resd extended end-!o-end anastomosis in 27 patients, and direct angioplasty with resection of web in 1 patient. The early mortality was 17.2% (27/157) and re-coarctation rate was 18.0% (281157). The most common complication was respiratory problem in infants and postoperative hypertension in children.

• Journal of Gastric Cancer
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• 제4권3호
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• pp.196-203
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• 2004

The Information Committee of the Korean Gastric Cancer Association sent questionnaires to 31 laparoscopic gastric surgeons about their personal experiences with laparoscopic gastric surgery from 2001 to 2003. Twenty-four surgeons responded to the questionnaires (response rate: $77.4\%$).The number of laparoscopic gastric surgeries from 2001 to 2003 was 1,130 and increased from 209 in 2001 to 593 in 2003. The number of operations for a gastric adenocarcinoma also increased from 87 cases in 2001 to 403 cases in 2003. Laparoscopic radical procedures, such as a laparoscopyassisted distal gastrectomy or total gastrectomy (LADG or LATG), have increased rapidly during this period. (55 cases in 2001, 150 cases in 2002, and 364 cases in 2003). Laparoscopic function-preserving gastrectomies were not performed until 2003, during which year one pylorus- preserving gastrectomy and six proximal gastrectomies were performed laparoscopically. A wedge resection for a gastric submucosal tumor was performed in 71 cases in 2001, 82 in 2002, and 103 in 2003. Hand-assisted laparoscopic surgery (HALS) was performed in 39 cases in 2001, 55 in 2002, and 49 in 2003. As for personal indications for a LADG, 14 surgeons performed a LADG only for a T1 lesion, and 5 surgeons extended their indications to T2N0 lesions. In the near future, laparoscopic procedures for gastric cancer will be widely adopted in Korea if the medical-insurance obstacle is overcome and the long-term survival results are verified.

• Journal of Korea Spatial Information System Society
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• 제1권1호
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• pp.5-18
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• 1999

Recently, the necessity of automatic knowledge extraction from spatial data stored in spatial databases has been increased. Spatial data mining can be defined as the extraction of implicit knowledge, spatial relationships, or other knowledge not explicitly stored in spatial databases. In order to extract useful knowledge from spatial data, an object management system that can store spatial data efficiently, provide very fast indexing & searching mechanisms, and support a distributed computing environment is needed. In this paper, we designed and implemented an open object management system for spatial data mining, that supports efficient management of spatial, aspatial, and knowledge data. In order to develop this system, we used Open OODB that is a widely used object management system. However, the lark of facilities for spatial data mining in Open OODB, we extended it to support spatial data type, dynamic class generation, object-oriented inheritance, spatial index, spatial operations, etc. In addition, for further increasement of interoperability with other spatial database management systems or data mining systems, we adopted international standards such as ODMG 2.0 for data modeling, SDTS(Spatial Data Transfer Standard) for modeling and exchanging spatial data, and OpenGIS Simple Features Specification for CORBA for connecting clients and servers efficiently.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• 제12권6호
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• pp.33-42
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• 2012

Rapid evolution of wired and wireless technologies results in various types of embedded systems, and the software to be embedded into those devices now needs the flexibility rather than the fixedness which was well-known property for the embedded software in the past. Mobile agent is one of the useful distributed technologies of reducing network load and latency because of its disconnected operations and high asynchrony. In this paper, a component-based mobile agent framework, called EmHUMAN, is designed and implemented for structural embedding into the devices showing different functions and resource constraints. It consists of 3 layers of components. Based on those components, a structural embedding, considering resource constraints of required functions, amount of storage space, computing power, network bandwidth, ${\ldots} $ etc can be performed. The components in each layer can be extended with addition of new components, removing some components and modifying components. EmHUMAN plays the role of a framework for developing mobile agent based distributed systems. It is also a mobile agent system by itself. EmHUMAN provides several utilities as built-in API's, and thus high effectiveness in programming mobile agents can be achieved.

• Journal of Integrative Natural Science
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• 제4권2호
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• pp.149-157
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• 2011

Urbanization of the world's population has given rise to more than 450 cities around the world with populations in excess of 1 million (megacity) and more than 25 so-called metacities with populations over 10 million (Brinkhoff, 2010). The United States today has a total resident population of more than 308,500,000 people, with 81 percent residing in cities and suburbs as of mid - 2005 (UN, 2008). Urban meteorology is the study of the physics, dynamics, and chemistry of the interactions of Earth's atmosphere and the urban built environment, and the provision of meteorological services to the populations and institutions of metropolitan areas. While the details of such services are dependent on the location and the synoptic climatology of each city, there are common themes, such as enhancing quality of life and responding to emergencies. Experience elsewhere (e.g., Shanghai, Helsinki, Tokyo, Seoul, etc.) shows urban meteorological support is a key part of an integrated or multi-hazard warning system that considers the full range of environmental challenges and provides a unified response from municipal leaders. Urban meteorology has come to require much more than observing and forecasting the weather of our cities and metropolitan areas. Forecast improvement as a function of more and better observations of various kinds and as a function of model resolution, larger ensembles, predicted probability distributions; Responses of emergency managers, government officials, and users to improved and probabilistic forecasts; Benefits of improved forecasts in reduction of loss of life, property damage, and other adverse effects. A national initiative to enhance urban meteorological services is a high-priority need for a wide variety of stakeholders, including the general, commerce and industry, and all levels of government. Some of the activities of such an initiative include: conducting basic research and development; prototyping and other activities to enable very--short and short range predictions; supporting and improving productivity and efficiency in commercial and industrial sectors; and urban planning for long term sustainability. In addition urban test-beds are an effective means for developing, testing, and fostering the necessary basic and applied meteorological and socioeconomic research, and transitioning research findings to operations. An extended, multi-year period of continuous effort, punctuated with intensive observing and forecasting periods, is envisioned.

• Journal of the Institute of Electronics Engineers of Korea TC
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• 제45권7호
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• pp.32-37
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• 2008

Satellite communication systems including the DVB-S2 (Digital Video Broadcasting - Satellite Version 2) system require operations under low signal-to-noise ratio (SNR) and large frequency offset values, and the initial frame synchronization process necessitates a robust correlation method. While a variety of conventional correlation structures exist for the initial synchronization, each method has different characteristics and performance in different channel environments. In this paper, we propose new correlation methods which exhibit enhanced performance in low SNR and large frequency offsets, and analyze their performance. The proposed methods use the magnitude sum and vector sum of extended differential correlation values, to maximize the correlation between the received signal and the synchronization sequence by using the spanned differential correlation result. The magnitude sum correlation method has better performance compared to conventional methods including the approximated ML (Maximum likelihood) method for SNR values below 4 dB with or without frequency offsets. The vector sum correlation method has improved performance over the magnitude sum method for channels with relatively small frequency offsets.

• The KIPS Transactions:PartD
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• 제13D권3호
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• pp.405-414
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• 2006

These days, business environments are rapidly change and companies are taking the pressure about a customer value enhance to the continuance from the market. Therefore companies propel various innovative and strategic initiatives for a customer value enhancement. Also Information Technology is rapidly becoming part of our everyday lives due to its fast development, the functions and responsibilities of CSC(Consolidated Service Center) are undergoing revolutionary change. The function of sales organization based on the manpower and human networks are gradually shrinking, and CSC is slowly establishing itself as the company's core parts as its function expands and its operations are in the spotlights. Among these, many organizations are currently introducing ITSM concept for primary processes as a means of achieving synergy in operational excellence, reducing costs and improving service quality. In this thesis, we propose an extended CSC, which is applied ITIL Process to traditional BMP. It also needs to manage more effectively business process model, to modeling rapidly changing business process, and to developing its business application programs whenever and whatever it is changed. The ITSM(IT Service Management), which is an ITIL tool, effectively managing for dynamically changing the business process.