• 한국정보통신학회논문지
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• 제11권1호
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• pp.206-215
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• 2007

Ad-Hoc 네트워크 기술이 미래의 이동 인터넷 기술로서 이동통신망(Mobile Network) 뿐만 아니라 공중무선랜망(WPAN) 그리고 유비쿼터스 망 등에 광범위하게 활용되기 위해서는 개선 및 보완되어야 할 기술적인 문제들이 많다. 특히, 최근 네트워크 보안의 허점을 이용한 보안상 공격이 급증하고 있는 상황에 반하여 Ad-Hoc 라우팅 프로토콜 연구 대부분은 보안 위협 요소를 배제하고 안전한 환경을 가정한 채 수행되고 있다. 또한 Ad-Hoc 네트워크가 무선 매체 특성상 더욱 많은 보안상 위협에 노출되기 쉽고 유선에서 사용되던 보안 메커니즘을 그대로 적용되는 것이 부적합함을 고려할 때 Ad-Hoc 보안에 관한 연구는 더욱 활발히 이루어져야 할 것이다. 따라서 본 논문에서는 Ad-Hoc 네트워크의 특성을 고려하여 중앙 집중적인 인증기관이나 키 분배센터에 의존하지 않고 클러스터를 구성하고 있는 멤버 노드들 간의 협력적이고, 분산된 인증서를 이용한 인증 서비스를 제공할 수 있는 모델을 제안한다. 아울러 시뮬레이션을 통해 제안한 모델의 확장성과, 견고성을 평가해 본다.

• 정보관리학회지
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• 제40권1호
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• pp.175-198
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• 2023

본 연구에서는 성격유형과 흥미유형에 따른 독서 감상문에 나타난 독서에 대한 반응의 차이를 탐구하였다. 이를 위해 대전의 D과학고등학교 3학년 학생 81명을 대상으로 성격유형분석 데이터, 흥미유형분석 데이터, 교과독서 활동으로 작성된 독서 감상문 데이터를 수집하였다. 수집된 독서 감상문의 토픽 분석을 수행하고, 성격유형(사고형, 감정형)과 흥미유형(탐구형, 탐구형 외)에 따른 독서 감상문의 토픽 발현 확률을 통계적으로 검증하였다. 이어서 키워드 네트워크 분석을 통해 단어들의 개념 연결 구조를 측정하고, 중심성 지표를 통해 토픽모델링의 분석 결과를 보완하였다. 연구 결과, 토픽 회귀분석을 통해 토픽2(이해와 공부)와 토픽3(읽기와 사고)에서 사고형(T)과 감정형(F) 간에 통계적으로 유의한 차이를 확인할 수 있었으며, 토픽2(이해와 공부)에서 탐구형과 탐구형 외 간에 통계적으로 유의한 차이가 확인되었다. 본 연구의 결과는 맞춤형 도서 추천이나 개인화를 고려한 독서교육의 기초자료로 활용될 수 있을 것이다.

• Advances in nano research
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• 제15권1호
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• pp.35-48
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• 2023

Nanoparticles are known for their outstanding properties such as particle size, surface area, optical and electrical properties. These properties have significantly boasted their applications in various surface phenomena. In this work, calcium oxide nanoparticles were synthesized from periwinkle shells as an approach towards waste management through resource recovery. The sol gel method was used for the synthesis. The nanoparticles were characterized using X-Ray diffractometer (XRD), Fourier Transformed Infra-Red Spectrophotometer (FTIR), Brunauer Emmett Teller (BET), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and ultra violet visible spectrophotometer (UV-visible). While DLS and SEM underestimate the particle diameter, the BET analysis reveals surface area of 138.998 m²/g, pore volume = 0.167 m³/g and pore diameter of 2.47 nm. The nanoparticles were also employed as an adsorbent for the purification of dye (methyl orange) contaminated water. The adsorbent showed excellent removal efficiency (up to 97 %) for the dye through the mechanism of physical adsorption. The adsorption of the dye fitted the Langmuir and Temkin models. Analysis of FTIR spectrum after adsorption complemented with computational chemistry modelling to reveal the imine nitrogen group as the site for the adsorption of the dye unto the nanomaterials. The synthesized nanomaterials have an average particle size of 24 nm, showed a unique XRD peak and is thermally and mechanically stable within the investigated temperature range (30 to 70 ℃).

• Korean Journal of Radiology
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• 제25권1호
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• pp.74-85
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• 2024

Objective: Idiopathic intracranial hypertension (IIH) is a condition of unknown etiology associated with venous sinus stenosis. This study aimed to develop a magnetic resonance venography (MRV)-based radiomics model for predicting a high trans-stenotic pressure gradient (TPG) in IIH patients diagnosed with venous sinus stenosis. Materials and Methods: This retrospective study included 105 IIH patients (median age [interquartile range], 35 years [27-42 years]; female:male, 82:23) who underwent MRV and catheter venography complemented by venous manometry. Contrast enhanced-MRV was conducted under 1.5 Tesla system, and the images were reconstructed using a standard algorithm. Shape features were derived from MRV images via the PyRadiomics package and selected by utilizing the least absolute shrinkage and selection operator (LASSO) method. A radiomics score for predicting high TPG (≥ 8 mmHg) in IIH patients was formulated using multivariable logistic regression; its discrimination performance was assessed using the area under the receiver operating characteristic curve (AUROC). A nomogram was constructed by incorporating the radiomics scores and clinical features. Results: Data from 105 patients were randomly divided into two distinct datasets for model training (n = 73; 50 and 23 with and without high TPG, respectively) and testing (n = 32; 22 and 10 with and without high TPG, respectively). Three informative shape features were identified in the training datasets: least axis length, sphericity, and maximum three-dimensional diameter. The radiomics score for predicting high TPG in IIH patients demonstrated an AUROC of 0.906 (95% confidence interval, 0.836-0.976) in the training dataset and 0.877 (95% confidence interval, 0.755-0.999) in the test dataset. The nomogram showed good calibration. Conclusion: Our study presents the feasibility of a novel model for predicting high TPG in IIH patients using radiomics analysis of noninvasive MRV-based shape features. This information may aid clinicians in identifying patients who may benefit from stenting.

• 동의생리병리학회지
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• 제16권5호
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• pp.989-1000
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• 2002

The purpose of this study is to examine the toxic effects caused by xanthine oxidase/hypoxanthine(XO/HX) and the effects of herbal extracts such as JHYJ and GJHYJ on the treatment of the toxic effects. For this purpose, experiments with the cultured hippocampal cells from new born mice were done. The results of these experiments were as follows. 1. XO/HX, a oxygen radical-generating system, decreased the survival rates of the cultured cells on XTT assay and INT assay, the amount of DNA syntheses, and the amount of neurofilaments, and increased the lipid peroxidation. 2. JHYJ and GJHYJ have the efficacy of increasing the survival rates of the cultured cells. 3. JHYJ and GJHYJ have the efficacy of increasing the amount of neurofilaments and of decreasing the lipid peroxidation. 4. JHYJ and GJHYJ have the efficacy of increasing the amount of DNA syntheses. From the above results, it is suggested that Jihwangyeumja and Gamijihwangyeumja have marked efficacy as a treatment for the damages caused by the XO/HX-mediated oxidative stress. And Jihwangyeumja and Gamijihwangyeumja are thought to have certain pharmacological effects. Further dinical study of this pharmacological effects of Jihwangyeumja and Gamijihwangyeumja should be complemented.

• 동아시아식생활학회지
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• 제24권2호
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• pp.275-282
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• 2014

This study developed Bucheon customized children meal hygiene central control point (CCP) to promote practical hygiene and safety management in a children meal supply organization in Bucheon. Education was administered to 54 organizations using the developed CCP, and the study evaluated kitchen hygiene management improvement effects. When the effects of hygiene education in eight categories (CCP 1~8) were examined, total scores increased by 9.31 from $22.36{\pm}5.039$ before education to $31.67{\pm}3.262$ with a statistically significant difference (p<0.001). After CCP education, personal hygiene management, food material management, cooking management, serving management, facility and equipment management improved significantly. The result demonstrates that CCP education was effective for kitchen hygiene management. Using CCP education, overall CCP education items were significantly improved, but there was almost no significant increase in the non-relevant item of CCP education. As there was an average difference in the non-relevant item of CCP education after follow-up evaluation, CCP education had an overall effect on hygiene and safety improvement. Based on the above result, the effect could be potentiated if CCP is complemented, if a systematic hygiene management manual is developed for the nationwide children meal supply organization, and if CCP education media is continually developed along with education.

• 정보교육학회논문지
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• 제11권1호
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• pp.59-66
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• 2007

본 연구는 로봇을 활용한 프로그래밍학습이 초등학생 및 초등영재들에게 창의력 향상에 도움을 주는 과학적인 학습도구라 판단되어 교육과정을 개발하였다. 이를 기초로 교재를 작성하고 현장에 직접 적용하여 그 결과를 분석하였다. 교육과정과 교재의 내용은 다양한 문제 상황에 맞는 로봇을 직접 제작하고 프로그래밍하는 과정(모두 6단계)으로 구분하고 학습수준에 맞게 편집함으로서 초등학생들이 로봇과 프로그래밍에 흥미와 관심을 가질 수 있도록 하였다. 로봇교육을 현장에 적용한 결과 창의성교육 도구로서 긍정적인 학습도구로 평가되었다. 또한, 수월성교육을 위한 학습도구로서 몇 가지 보완해야 할 결론도 함께 얻었다.

• 한국조경학회지
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• 제30권4호
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• pp.82-91
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• 2002

The site for this plan is located at the foot of Mt. Unseo at Galcheon-ri, Changsu-myon, Youngdeok-gun. On the site stands Jangyutsa Temple, built by priest Naong in 1355 (in the 4th year of King Gongmin during Koryo Kingdom). The purpose of this plan is to widely publicize and commemorate priest Naong by designing a district centering around the temple. The basic directions of design can be summarized as follows 1) A special Buddhists'pilgrimage and sight-seeing district aimed at commemorating priest Naong will be developed to preserve the historic figure of priest Naong. To this end, a facility will be built to collect, preserve and exhibit materials related with the great priest in order to preserve his legacy and enhance the image of the space. 2) Special fractions which are rare in other districts will be introduced to create an image different from the conventional memorial districts or sight-seeing zones. To this end, the district will be divided into the Jangyuksa Temple area proper and a district memorial area, each of which will have its own unique characteristics with different functions. On the other hand, the two different areas will be related with each other and complemented by each other. Such planning techniques as articulation and superimposition will be used for a synergistic effect. 3) The plan will accommodate various programs centering around historical and cultural assets, and at the same time will allow tourists to have various experiences and access to the natural environment as well as to a variety of events. 4) In order to plan such landscapes as shown in the traditional mountain temples, the traditional tectonic forms will be used for the facilities. It is expected that the district surrounding Jangyuksa Temple will become a popular sight-seeing destination, and with new historical and cultural environments will become a valuable resource to widely publicize the culture of Youngdeok-gun.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.99.1-100
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• 2003

E. intermedium Blocontrol activity of a P. chlororaphis rhizobacteium O6, depends to the synthesis of extracellular secondary metabolites and exoenzymes, thought to antagonize the pathogenicity of a variety of phytopathogenic fungi. The production of secondary metabolites and exoenzymes in O6, depends essentially on the GacS-mediated signal transduction pathway, which activates largely unknown signal transduction pathway. To exploit the GacS-mediated signal transdcution pathway involved in activation of ph genes that are necessary for biosynthesis of phenazine from P. chlororaphis O6, we cloned and sequenced the phz operon, rpoS gene encoding stationary specific sigma factor, ppx gene encoding polyphosphatase, and lon gene encoding ion protease. Expression of each gene in wild type and GacS mutant were analyzed by RT-PCR. Transcripts from rpoS, phzI enconing acylhomoserine lactone (AHL) synthase, and ph structural genes in the GacS mutant were reduced in each of these growth phases compared to the wild type. The GacS or Lon mutant was found to be deficient in the production of phenzines, exoenzymes, and the acylhomoserine lactone. These mutants were not complemented by ph operon and addition of exogenous AHL. These results indicate that the GacS global regulatory systems controls phenazine production at multiple levels. Future research will focus to identifying the GacS-mediated regulatory cascade involving in production of phenazine in P. chlororaphis.

• 한국식생활문화학회지
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• 제3권1호
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• pp.89-93
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• 1988

국내 도시락 공장을 조사 분석하여 대량생산에 적합토록 그 문제점을 보완 개선했다. 특히 식품위생법과 건축법상의 공장허가 사항을 고려해서 3가지 면적별로 모델 도시락 공장을 설계하였다. 작업장은 하나의 개방공간에 배치된 기기류를 오염지역, 준청결지역, 청결지역으로 나누어 작업중의 2차오염 문제를 배제시켰고, 기기류는 밥급속냉각기, 냉장고 겸 냉각기를 설치하여 위생안전성을 부여했으며, 청결실에 멸균(집진)기를 설치하여 완제품의 초기 미생물 농도를 줄이고 2차오염 요인을 제거함으로써 위생적인 도시락 생산유통이 가능한 도시락 생산공장을 설계하였다.