• Journal of the Korean Society of Safety
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• v.14 no.3
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• pp.101-109
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• 1999

This study attempts to analyse the solid mixing in the feeder and the packing effect for pressure fluctuations in the fluidized bed. To study the mixing characteristics of solid in vibrating feeder for the stable operations of fluidized combustion, the system consisted of two groups of particles such that fine particles were located on the top of the coarse particles before vibratory mixing had started. The effects of packing materials on the pressure fluctuations in a fluidized bed were analysed by using a statistical method to interpret the behavior of fluidized bed. The experiments were carried out in a fluidized bed of 6.7cm-ID, and the experimental variables were particle sizes, of 115 to 1,015$\mu\textrm{m}$ in diameter and the multi-sized particles haying Rosin-Rammler and Gaussian distributions. The settled bed heights of particles to diameter ratios (L/D) were ranged from 0.5 to 2.0. And fluidizing of particles was carried out by air. The packing materials used were screen packing, and the properties of the pressure fluctuations in the fluidized bed were measured by a differential pressure transducer. The properties of the pressure fluctuations calculated were the mean, the standard deviation, and the major frequency of the power spectral density functions. From the characteristics of fluidizing, it was found that the standard deviation of pressure fluctuations could be effectively used to explain the fluidized phenomena, and the packing materials affected severely the properties of the pressure fluctuations. As a result, from the interpretation by spectral analysis, the effects of measuring radius of pressure fluctuations on standard deviation were constant in the case of the fluidized bed with and without packing materials. However, the effects of measuring the height of pressure fluctuations on standard deviations were linear increasing for the fluidized bed with packing materials, but were constant for the fluidized bed without packing materials at 4.5cm above the gas distributor. The major frequency of pressure fluctuations was found to be nearly independent of fluidized system. Also, the major frequency of pressure fluctuations decreased with increasing packing size, and it had maximum value at 10% of the packing amount.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.05a
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• pp.226-230
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• 2003

In this thesis I analyzed that V5.2 protocol function is effective to fulfill all of the services that are provided at the existing local exchange. I analyzed this in five methods that refer to ETSI inside patronage. I experimented turnaround time by Start-up method and verified V5.2 protocol function when Start-up. Also I confirmed stability of system by the reconstruction-ability experiment related E1 switch over. I verified V5.2 protocol function through PSTN call process that uses a special service test and local call simulator. As a result of experiment, I confirmed the best method when simultaneous Start-up. V5.2 protocol function was excellent and It becomes switch over at 1/1000 seconds when E1 is out of service. V5.2 protocol function was effective to fulfill all of the special services that are provided at local exchange and its long call process ability was superior to KT standard with 4 fails in 20000 calls. Through the experiment, it was proved that V5.2 interface will become a significant element of communication network when after LE side expanse of v5 interface ID with TDX-100 exchanger and the AN occurrences OOS by message transmission limit and call disconnect when E1 switch over are improved.

• The KIPS Transactions:PartD
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• v.8D no.4
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• pp.361-366
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• 2001

As growing the number of Webs, the total amount of accessible information has been greater than ever. To storage and retrieve the vast information on the Webs effectively, many researchers have been made utilizing XML (extensible Markup Language). In this paper, we propose an effective method of representation and retrieval mechanism for the structured retrieval of the XML documents : (1) the fixed sized LETID (Leveled Element Type ID) that contains the information of elements such as parent node, sibling nodes, and identical sibling nodes, and the hierachical information of current node, and (2) content index, structure index, attribute index model, and the information retrieval algorithm for the structured information retrieval. With our methods, we can effectively represent the structured information of XML documents, and can directly access the specific elements by simple operations to process various queries.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.307-307
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• 2013

초고집적 회로에 적용되는 반도체 소자의critical dimension (CD)이 수 nano 사이즈로 줄어들고 있기 때문에, 다양한 물질의 식각을 할 때, 건식식각의 중요성이 더 강조되고 있다. 특히 $SiO_2$와 같은 유전체 물질을 식각할 때, plasma process induced damages (P2IDs)가 관찰되어 왔고, 이러한 P2IDs를 줄이기 위해, pulsed-time modulation plasma가 광범위하게 연구되어 왔다. Pulsed plasma는 정기적으로 radio frequency (RF) power on과 off를 반복하여 rf power가 off된 동안, 평균전자 온도를 낮춤으로써, 웨이퍼로 입사되는 전하 축적을 효과적으로 줄일 수 있다. 또한 fluorocarbon plasmas를 사용하여 $SiO_2$를 식각하기 위해 Dual-Frequency Capacitive coupled plasma (DF-CCP)도 널리 연구되어 왔는데, 이것은 기존의 방법과는 다르게 plasma 밀도와 ion bombardment energy를 독립적으로 조절 가능하다는 장점이 있어서 미세 패턴을 식각할 때 효과적이다. 본 연구에서는 Source power에는 60 MHz pulsed radio frequency (RF)를, bias power에는 2 MHz continuous wave (CW) rf power가 사용된 system에서 Ar/$C_4$ F8/$O_2$ 가스 조합으로, amorphous carbon layer (ACL)가 hard mask로 사용된 $SiO_2$를 식각했다. 그리고 source pulse의 duty ratio와 pulse frequency의 효과에 따른 $SiO_2$의 식각특성을 연구하였다. 그 결과, duty ratio의 감소에 따라 $SiO_2$, ACL의 etch rate이 감소했지만, $SiO_2$/ACL의 etch selectivity는 증가하였다. 반면에 pulse frequency의 변화에 따른 두 물질의 etch selectivity는 크게 변화가 없었다. 그 이유는 pulse 조건인 duty ratio의 감소가 전자 온도 및 전자 에너지를 낮춰 $C_2F8$가스의 분해를 감소시켰으며, 이로 인해 식각된 $SiO_2$의 surface와 sidewall에 fluorocarbon polymer의 형성이 증가하였기 때문이다. 또한 duty ratio의 감소에 따라 etch selectivity뿐만 아니라 etch profile까지 향상되는 것을 확인할 수 있었다.

• Korean Journal of Clinical Laboratory Science
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• v.42 no.2
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• pp.63-70
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• 2010

Antibody screening and identification tests before blood transfusion are important because unexpected red antibodies can cause acute or delayed hemolytic transfusion reactions. Although a tube method was used for detecting unexpected antibodies, a column agglutination method has recently been used because of its simple procedure and a high detection of warm antibodies. This study investigated the frequency and distribution of unexpected antibodies in transfusion candidates during the recent 5 years, and transfusion characteristics in the identified cases. From January 2005 to December 2009, 46,923 sera of the cases from E hospital were screened and 98 sera were identified by the DiaMed-ID System. 272 cases (0.58%) showed positive results out of all 46,923 cases that underwent unexpected antibodies screening. Among them, unexpected antibodies were identified in 98 cases. The anti-Rh antibodies included in warm antibodies were the most frequently detected in 47 cases (47.96%). Anti-Lewis and anti-MNSs antibodies were detected in 11 cases (11.22%) and 6 cases (6.12%), respectively. Unidentified antibodies were detected in 6 cases (6.12%). Among the patients with unexpected antibodies, 43 cases (43.88%) had a history of previous transfusion. Anti-E was the most frequently detected antibody (4/14 cases, 30.77%) in the cases who had a previous history of transfusion and showed different screening results from negative to positive, This study may provide the basic data for the frequency and characteristics of red cell antibodies.

• Journal of Nutrition and Health
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• v.31 no.4
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• pp.739-746
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• 1998

This study was designed to investigated the antitumor effect and change chemosensitivity of chitosan in 2 kinds of humen lung cancer cell lines(NCI-H522, NCI-H596). To evaluate the antitumor effect and synergistic effectof chomosensitivity, MTT assay was used in vitro. then anticancer drugs used were 챤-platin , ectoposide, and adrimycin. The results of this study were as follows; Chitosan shwoed in antitumor effect on both NCI-H522 and NCI-H596. The lung cancer viability percent for NCI-H522 and NCL-H596 showed at the lowest levels of 5.31 and 5.33% when the concentration of chitosan was 25mg/$m\ell$ media and the exposure time of chitosan was 72 hours. ID50 value of chitosan on both NCI-H522 and NCI-H596 showed at the lowest levels of 14.07, 11.68 mg/$m\ell$ media when the exposure time of chitosan was 72 hours. the synergistic effect of chomosensitivity was better in NCI-H596 than in NCI0H522 . When the synergistic effect of chomosensitivity was shown according to the kind of the anticancer drugs, in case of NCI-H522 , in the concentration of 100$\mu\textrm{g}$/$m\ell$, ectoposide showed the highest synergistic effect of chomosensitivity and then was adrimycin In case of NCI-H596, in the concentration of 100$\mu\textrm{g}$/$m\ell$,, the order of the synergistic effect of chomosensitivity was ectoposide>adrimycin>cis-platin and in the concentration of 10$\mu\textrm{g}$/$m\ell$, ectoposide>cis-platin >adrimycin. It is concluded that chitosan is an active antitumor agent and is increased chomosensitivity though there is difference according to the kind and the concentration of anticancer drugs. But to be sued to lung cancer theraphy, further studies on toxicity, the mechanism of action, animal experiment are wanted.

• Journal of Korea Technology Innovation Society
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• v.14 no.4
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• pp.1050-1072
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• 2011

It is well known that international cooperation is considerably more difficult because of the difference of interests, level of technology of the partners, social and culture as well as various macro-environmental conditions. This case study aims to investigate the success factors of international R&D collaboration between two firms. For it, an in-dept interview was conducted to the Etri-Microsoft Information Security Lab. A comprehensive research on theories, such as resource-based theory, network theory, relationship marketing theory and market power perspective was done as well. The results show clear objectives, communications based on trust, core competence on which the counterpart can rely on, consideration on the government decision process as well as the environment are important for success.

• Journal of the Korea Computer Industry Society
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• v.8 no.4
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• pp.253-262
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• 2007

As the internet environment is applied in the various service field, the recognition on security is increasing. Because the authentication methods for web service user do not confirm person oneself, the serious problems of reliability, safety and security can be caused. In order to solve this problems, the authentication methods of user id and password or authentication key is used. Because the password and authentication key using the existent authentication methods for security is composed of a string, authentication information can easily hacked or leaked by hackers, and the serious problems of security can be caused. In this paper, in order to improve the web security, an authentication module using the fingerprint that have the unique properties of person is proposed. As the proposed module makes use of fingerprint authentication, the security of the web service user from hackers can be maintained. The proposed method is more excellent than the existent method in the web security.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.47 no.4
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• pp.51-62
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• 2010

This paper proposes RSA cryptosystem based anonymous electronic prescription which is issued from university and local hospitals by authorized medical professionals. Electronic prescription is now being used in domestic hospitals where sharing medical records and images are prevailing, facilitated by digitalizing medical information and building network infrastructure between the institutes. Proposed RSA based anonymous electronic prescription makes use of PKI protects the identity exposure of doctors and privacy of patients. While traditional prescription fails to protect identities to mandates party or to health insurance, the proposed RSA based prescription opens the contents of the prescription to health insurance authority only after its prescribing function is finished. The proposed approach along with soon to be deployed electronic ID card will help national health insurance corporation to increase the transparency of national prescription system.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.29 no.4
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• pp.212-218
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• 2003

Matrix metalloproteinases (MMPs) play an important role in the normal morphogenesis, maintenance, and repair of matrix and also have important functions in pathologic conditions characterized by excessive degradation of extracellular matrix, such as rheumatoid arthritis, osteoarthritis, periodontitis and in tumor invasion and metastasis. In this study, expression of MMP-1 and -2 mRNA in retrodiscal tissue of the temporomandibular joint (TMJ) was examined and compared with magnetic resonance imaging (MRI) and surgical findings. MMP mRNAs in the retrodiscal tissue samples were detected by reverse transcription - polymerase chain reaction. TMJ internal derangement (ID) was categorized as normal disc position, disc displacement with reduction, early stage of disc displacement without reduction (DDsR) and late stage of DDsR. TMJ osteoarthrosis (OA) was classified with normal, mild and advanced OA. The amount of synovial fluid collection was divided into not detected, small, large and extremely large amount on MR T2-weighted imaging. Perforation and adhesion were examined during open surgery of the TMJ. Six out of 37 samples were excluded because of little amount of extracted total mRNA. MMP-2 mRNA was detected whole joints, and so the MMP-2 mRNA seems to be expressed normally in retrodiscal tissue. However, MMP-1 mRNA was expressed in 8 of 31 joints. Frequencies of MMP-1 mRNA expression according to the TMJ IDs, amount of synovial fluid and surgical findings made no significant difference. MMP-1 mRNA was detected more frequently in OA groups (7/16 joints, 43.8%) than in normal bony structure group (1/15 joints, 6.7%). Expression of MMP-1 mRNA in retrodiscal tissue might be related with OA of the TMJ.