• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.4
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• pp.929-935
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• 2008

As internet telephony services based on Session initiation Protocol (SIP) enter the spotlight as marketable technology, many products based on SIPs have been developed and utilized for home and office telephony services. The call connection of an internet phone is classified into specific call connections and group call connections. Group call connections have a forking function which delivers the message to all of the group members. This function requires excessive message control for a call connection and creates heavy traffic in the network. In the internet cail system model. most of the call-setup messages are directed to the proxy server during a short time period. This heavy message load brings an unwanted delay in message processing and. as a result, call setup can not be made. To solve the delay problem, we simplified the analysis of the call-setup message in the proxy server, and processed the forking function distributed for the group call-setup message. In this thesis, a new system model to minimize the load is proposed and the subsequent implementation of this model demonstrates the performance improvement.

• Journal of Korea Technology Innovation Society
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• v.10 no.2
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• pp.334-360
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• 2007

This paper presents an emerging concept, professional mobility in S&T innovation system, that focus on the utilization of highly qualified researchers without recruiting. In this paper we divided the utilization of external researcher into four types: (1)visiting/post-Doc/guest researcher, (2)collaborating research student, (3)part-timer or trainee and (4)foreign researcher. From 2002 to 2005 in 19 Korean government-funded research institutes, while total researchers have increased by 13.3%, external researchers have decreased from 39.2% to 35.7%. In 2005, visiting and foreign researchers were only 6.5% of total external researchers. It may indicate that the innovation capability of Korean research institutes is on the quite limited situation compared to foreign research institutes. The financial and institutional support programs for promoting the professional mobility are also insufficient in Korean S&T innovation system.

• Korean Journal of Ecology and Environment
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• v.45 no.1
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• pp.34-41
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• 2012

The variation of dissolved oxygen (DO) was monitored with high frequency by an automatic data-logging sensor in a eutrophic urban stream (the Anyang Stream) located in a metropolitan area of Seoul, South Korea. In general, DO showed the diel variation of increase in daytime and decrease at night, implying that primary production is a major mechanism of oxygen supply in this ecosystem. The fluctuation of oxygen was determined by rainfall. DO depletion was most obvious after a rainfall resulting in an anoxic condition for a day, which is thought to be caused by scouring of periphyton and organic ooze at the stream bottom. Seasonally DO was higher in winter and frequently depleted in warm seasons. DO depletion was often at a dangerous level for fish survival. Fish survey showed that little fish was living at the study site and oxygen depletion may be the major stress factor for aquatic animals. From the results it can be suggested that a high frequency monitoring of oxygen should be established for the proper assessment of aquatic habitats and better management strategy.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.23 no.1
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• pp.19-25
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• 1993

The purpose of this study was to evaluate the prevalence and distribution of additonal root in the mandibular 1st molars and premolars by means of the analysis of the full mouth periapical radiographs in 6,082 patients visited the Dental Infirmary of Kyungpook National University Hospital from March 1989 to February 1993. The results were as follows: 1. The incidence of additional root in the mandibular 1st molars was revealed to be 9.32% in total examined patients, and there was a higher prevalence in males(I1.35%) than in females(7.46%). And bilateral occurrence was revealed to be 4.26%. 2. The incidence of additional root in the mandibular premolars was to be 3.57% in total examined patients, and there was a higher prevalence in males(4.28%) than in females(2.91%). And bilateral occurrence in the 1st premolars was revealed to be 1.53%.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.23 no.1
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• pp.71-85
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• 1993

The purpose of the study was to investigate the effects of the single and fractionated irradiation on the microvascular structure of the submandibular gland in rats. For this study, 90 Sprague-Dawley strain rats were irradiated to their neck region with equal split doses of 9Gy for a 4 hours interval and 15Gy single dose by 6MV X-irradiation and sacrificed on the 1st, 3rd, 7th, 14th and 27th day after irradiation. The author observed histological changes at Hematoxylin and Eosin staining and PAS staining under a light microscope, and also observed distribution and structural changes of the microvasculature in rat submandibular gland using a scanning electron microscope by forming vascular resin casting. The results were as follows: 1. In the light microscopic examination, the microvasculature was slightly dilated and decreased in number on the 1st day after irradiation, and increase in number of microvasculature was observed on the 3rd day after irradiation. And then distribution of microvasculature was markedly increased on the 7th day after iradiation, but decreased on th 14th day after irradiation again. Such changes were greater in the single irradiated group than in the fractionated irradiated group. 2. The reaction to PAS staining on glandular cell was decreased on the 1st and the 3rd day after irradiation, and recovered on the 7th day after irradiation. The reaction was decreased on the 14th day after irradiation again, and recovered on the 28th day after irradiation. Changes were more apparent in the single irradiated group. 3. In the scanning electron microscopic examination, early changes of microvasculature were decreased capillary density, dilation of conduits and meandering. Increased capillary dentsity or anastomosis due to vascular reproduction and smooth curved running were observed on the 7th and 14th day after irradiation. Decreased capillary and smooth running tendency were observed on the 28th day after irradiation again. Such changes were greater in the single irradiated group than in the fractionated irradiated group.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.24 no.2
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• pp.327-333
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• 1994

The purpose of this study was to investigate the irradiation effects on the palatal mucosa. For this study, Sprague-Dawley strain rats were irradiated to their head and neck region with the dose of 5Gy and l0Gy by 6MV X -radiation and sacrificed on the experimental periods after irradiation. The authors observed the histological changes of the hard and soft palatal mucosae. The results were as follows: In the light microscopic examination, hydropic change on the basal cells, increased cell size of the epithelium, and decreased epithelial cell layers were observed on the 3hours, 6hours, and 12hours groups after irradiation. But, basal cell hyperplasia, increased epithelial cell layers, and elongated rate pegs were observed on the 3days group after irradiation. After then, these changes were recovered in the mucosa of the hard palate on the 7days and 14days groups, and in the mucosa of the soft palate on the 14days and 2&lays groups after irradiation. And such changes were greater in the mucosa of the soft palate than in that of the hard palate, and more prominent in l0Gy irradiated groups than in 5Gy irradiated groups.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.4
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• pp.1005-1009
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• 2013

Using DNA sequencing method, we analyzed mutations of rpoB (RNA polymerase beta subunit) rifampin-resistant Mycobaterium tuberculosis strains which were identified by conventional test at Masan National Hospital and The Korean Institute of Tuberculosis. Though it has been reported different mutations of rpoB region of rifampin-resistant M. tuberculosis strains in the south of Korea, it is not confirmed whether these mutations of rpoB region actually express rifampin resistance through experiment. We confirmed experimentally these mutations of rpoB region of M. tuberculosis strains induced rifampin-resistance through ampified rpoB by polymerase chain reaction (PCR) and cloning of mutant rpoB into rifampin sensitive-M. tuberculosis strain.

• Journal of KIISE:Computer Systems and Theory
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• v.33 no.9
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• pp.563-573
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• 2006

Cyber-infrastructures for scientific and engineering applications require integrating heterogeneous legacy data in different formats and from various domains. Such data integration raises challenging issues: (1) Support for multiple independently-managed schemas, (2) Ease of schema evolution, and (3) Simple schema mappings. In order to address these issues, we propose a novel approach to semantic integration of scientific data which uses XML schemas and RDF-based schema mappings. In this approach, XML schema al-lows scientists to manage data models intuitively and to use commodity XML DBMS tools. A simple RDF-based ontological representation scheme is used for only structural relations among independently-managed XML schemas from different institutes or domains We present the design and implementation of a prototype system developed for the national cyber-environments for civil engi-neering research activities in Korea (similar to the NEES project in USA) which is called KOCEDgrid (http://www.koced.net).

• Imaging Science in Dentistry
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• v.42 no.2
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• pp.77-81
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• 2012

Purpose : The purpose of the present study was to retrospectively evaluate the clinical findings and treatment results for impacted permanent teeth associated with odontomas. Materials and Methods : We retrospectively investigated 73 odontomas in 72 patients who visited Kyungpook National University Dental Hospital from April 2004 through November 2011. The study was performed using medical records, panoramic radiographs, and pathological reports. Data gathered included age, gender, location, chief complaints, effects on dentition, and treatment of odontoma and the impacted tooth associated with odontoma. Results : Most compound odontomas (46.7%) were found in the second decade and complex odontomas were not related to age. Odontomas showed no gender predilection. Fifty-five cases (75.3%) of odontomas were detected on routine dental radiographs. Sixty percent of compound odontomas occurred in the canine area and 57.1% of complex odontomas in the molar areas. Impaction of permanent teeth (61.6%) was the most common complication on the adjacent teeth. Most odontomas (84.9%) were removed surgically and impacted permanent teeth were managed by surgical removal (53.2%), orthodontic treatment (25.5%), or surgical repositioning (6.4%). There was a statistically significant relation between age and preservation of the impacted permanent teeth associated with odontomas (p<0.01). Conclusion : Early detection and treatment of odontomas increase the possibility of preservation of the impacted tooth. Therefore, it would be suggested that periodic panoramic examination during the first and second decade of life might be beneficial for the early detection and better prognosis of odontomas.

• Journal of Korea Technology Innovation Society
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• v.13 no.2
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• pp.282-309
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• 2010

Recently, technology acquisition through technology trade plays a critical role in obtaining national competitiveness in a global era. However, current studies mostly focus on grasping the characteristics or macro status of technology trade and analyzing the impact of technology acquisition through the technology transaction, leading to the failure of providing a theoretical and practical background of national policy-making. Therefore, this research aims at investigating the concentration rate of technology, companies and countries where Korean companies obtain technological capability on the basis of the Bank of Korea's data related to 'loyalty payment in technology licensing', additionally analyzing the types of exported technology and loyalty payment. From these analyses, the degree of concentration that pre-defined 31 technology classifications depend on specific technologies, companies and nations are examined and the characteristics of technology trade types are investigated. The results of this research can be used to make a technology policy and analyze the characteristics of technology innovation of Korea industries.