• 한국콘텐츠학회논문지
• /
• 제10권9호
• /
• pp.487-495
• /
• 2010

본 연구는 온라인 정보영재 교육의 질적 제고를 위해 온라인 콘텐츠 평가 준거를 제시하였다. 선행연구를 통해 나타난 정보영재의 특징과 사고양식, 학습양식의 특성을 기반으로 정보영재를 위한 온라인 콘텐츠 평가 준거를 개발하였다. 개발된 평가 준거는 정보영재 전문가를 대상으로 문항 타당성 검사를 진행하였다. 분석 결과 전체 문항의 신뢰도는 .94로 신뢰롭게 나타났다. 그리고 문항 특성 부분인 변별도는 .53~.83이었고, 난이도에서도 만족할만한 결과 값을 보여주었다. 개발된 정보영재를 위한 온라인 콘텐츠 평가 준거는 '재능개발', '상호작용' 등 5개 평가 영역, 11개 평가 요인, 40개 평가 문항으로 구성하였다. 본 연구에서 제시한 평가 준거는 정보영재 온라인 콘텐츠 개발을 위한 가이드라인 및 온라인 교재 선택에 도움을 줄 수 있을 것으로 기대된다.

• 한국진공학회지
• /
• 제15권5호
• /
• pp.506-511
• /
• 2006

$Zn(NO_3)_2{\cdot}6H_2O$, 수산화나트륨, cyclohexylamine, 에탄올, 물이 혼합된 용액을 수열합성하여 ZnO 나노로드를 합성하고, 합성한 물질의 이산화 질소$(NO_2)$와 일산화 탄소(CO)에 대한 감응특성을 조사하였다. 혼합 용액에 첨가되는 물의 양을 변화시켜 ZnO 나노로드의 형상과 응집현상을 조절할 수 있었다. 이는 물과 cyclohexylamine의 반응에 의해 발생되는 $OH^-$ 이온의 농도변화에 의한 것으로 해석된다. 물의 함량이 낮을 때에는 뭉쳐진 성게모양의 ZnO 나노로드를, 물의 함량이 많을 때에는 잘 분산된 ZnO 나노로드를 각각 합성할 수 있었다. 잘 분산된ZnO 나노로드는 공기 중에서 50 ppm 의 CO에 노출되었을 때 주목할 만한 반응을 보이지 않는 반면, 1 ppm 의 $NO_2$에 노출되었을 때에는 저항이 1.8배 증가하였다. 이러한 선택적 반응을 보이는 ZnO 나노로드는 자동차용 자동환기 시스템의 핵심부품인 매연센서의 감응물질로 사용될 수 있다.

• Environmental Analysis Health and Toxicology
• /
• 제21권1호
• /
• pp.27-34
• /
• 2006

Numerous studies reported the significant association between genetic polymorphisms in the vitamin D receptor (VDR) gene and various bone phenotypes such as bone mineral density (BMD) and bone quality, although conflicting results were produced. The objective of this study was to investigate the association between a TaqI RFLP in the VDR gene and calcaneal BMD in Korean vegetarian men, and its interaction with nutrition status as an environmental factor. BUA (broadband ultrasound attenuation), SOS (sound of speed) and stiffness index of the calcaneus were measured using an ultrasound bone densitometer in 266 Korean men (age: $mean{\pm}SD;\;50.9{\pm}12.0$ year), and a TaqI RFLP in the VDR gene analysed by PCR-RFLP method. In total subjects, the distribution of TT, Tt and tt genotypes occurred with frequencies of 90.8%, 8.8% and 0.4%, respectively. There were no significant associations between this polymorphism and osteopenia-osteoporosis or several bone phenotypes in our subjects irrespectively of nutrition status (P>0.05). Therefore, our results suggest that a TaqI RFLP in the vitamin D receptor gene does not contribute to the susceptibility to the calcaneal BMD in Korean men.

• Journal of the Optical Society of Korea
• /
• 제13권1호
• /
• pp.28-32
• /
• 2009

In order to obtain high quality images of thin objects, we performed an experiment of proton radiography by using low energy protons generated from the interaction of an ultrashort ultraintense laser with solid targets. The protons were produced from a thin polyimide target irradiated by the laser pulse, and their maximum energy was estimated at up to 1.8 MeV. A CR-39 nuclear track detector was used as a proton radiography screen. The proton images were obtained by using an optical microscope and the spatial resolution was evaluated by a Modulation Transfer Function (MTF). We have achieved about $10\;{\mu}m$ spatial resolution of images. The obtained spatial resolution shows about $4{\sim}5$ times better value than the conventional X-ray radiography for inspection or non-destructive test (NDT) purpose.

• 디지털융복합연구
• /
• 제16권7호
• /
• pp.213-222
• /
• 2018

본 연구의 목적은 고등 수학교육에 있어서 스마트 러닝의 특징적 적용을 통해 교육환경의 확장과 학습자 역량의 확장을 시도하고 그 효과성을 분석하는 것이다. 본 연구는 2017년 G대학에서 1학년 학생들의 공학인증 과목 중 하나인 미적분학I을 수강하는 화공생명학과 학생들 118명을 실험집단과 비교집단으로 분리하여 스마트러닝의 효과성을 검증하였다. 즉 수업에서 공학도구를 활용한 다양한 학습활동과 SNS를 통한 교수자와 학습자 간의 활발한 상호작용이 시각적 이해와 수학적 개념형성, 그리고 학습성과에 미치는 영향을 분석하였다. 연구결과에 따르면 실험집단에서 긍정적인 학업성취를 보였으며 학습자들의 만족도가 높았다. 본 연구는 고등 수학교육에서 스마트러닝의 가능성을 확인하였으며 향후 질 높은 스마트러닝을 실현하기 위한 전략을 제안한다.

• 한국치위생학회지
• /
• 제20권3호
• /
• pp.269-279
• /
• 2020

Objectives: Previous studies have reported inconsistent findings in the association between dental diagnostic X-ray exposure and thyroid cancer. This study was a meta-analysis of case-control studies evaluating the association between exposure to dental radiation and the thyroid cancer risk. Methods: We searched the PubMed and EMBASE databases to identify studies on dental radiation and thyroid cancer risks that were published up to September 2018. Quality of studies was assessed using the Newcastle-Ottawa scale. A fixed-effects model was used to estimate pooled odds ratios (ORs) and 95% confidence intervals (CIs) using STATA 14.0. Potential publication biases were evaluated using Egger's test and Begg's funnel plot. Results: From the literature search, we included six case-control studies in this meta-analysis. The meta-analysis using the fixed-effects model found that dental X-ray exposure was associated with 2.34 times increased risk for thyroid cancer (OR=2.34, 95% CI=1.79-3.21). There was no heterogeneity in the data (p=0.662, I² =0%). Egger's test showed that there was no publication bias (p=0.532). Conclusions: This meta-analysis confirmed the association of dental X-ray exposure and thyroid cancer risk. The current results underscore the importance of applying safety regulations at dental clinics to protect thyroid glands during dental radiography examinations.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제5권1호
• /
• pp.24-51
• /
• 2011

When supporting both voice and TCP in a wireless multihop network, there are two conflicting goals: to protect the VoIP traffic, and to completely utilize the remaining capacity for TCP. We investigate the interaction between these two popular categories of traffic and find that conventional solution approaches, such as enhanced TCP variants, priority queues, bandwidth limitation, and traffic shaping do not always achieve the goals. TCP and VoIP traffic do not easily coexist because of TCP aggressiveness and data burstiness, and the (self-) interference nature of multihop traffic. We found that enhanced TCP variants fail to coexist with VoIP in the wireless multihop scenarios. Surprisingly, even priority schemes, including those built into the MAC such as RTS/CTS or 802.11e generally cannot protect voice, as they do not account for the interference outside communication range. We present VAGP (Voice Adaptive Gateway Pacer) - an adaptive bandwidth control algorithm at the access gateway that dynamically paces wired-to-wireless TCP data flows based on VoIP traffic status. VAGP continuously monitors the quality of VoIP flows at the gateway and controls the bandwidth used by TCP flows before entering the wireless multihop. To also maintain utilization and TCP performance, VAGP employs TCP specific mechanisms that suppress certain retransmissions across the wireless multihop. Compared to previous proposals for improving TCP over wireless multihop, we show that VAGP retains the end-to-end semantics of TCP, does not require modifications of endpoints, and works in a variety of conditions: different TCP variants, multiple flows, and internet delays, different patterns of interference, different multihop topologies, and different traffic patterns.

• 서비스연구
• /
• 제8권4호
• /
• pp.53-75
• /
• 2018

공유 자전거（bicycle-sharing）는 제품 서비스 시스템을 공유 경제（sharing economy）에 접목시킨 새로운 협력소비경제의 개념이다. 공유 자전거의 차별적 특징은 자전거 이용자가 자전거를 소유하고 있지 않더라도 자신이 원하는 시간에 원하는 지역에서 자전거를 타고 이동할 수 있다는 점이다. 중국의 경우, 공유 자건거가 제공하는 이러한 편익으로 인해 공유 자전거 이용자는 급격히 증가하고 있는 반면, 공유 자전거의 서비스 체험 품질과 사용자 만족도는 지속적으로 하락하고 있는 상황이다. 본 연구는 중국 내의 유저들이 공유 자전거 서비스 체험을 통해 지각하는 서비스의 품질을 실증분석을 통해 파악하고, 서비스가 제공되는 과정에서 발생할 수 잠재적인 문제점을 도출한 다음, 서비스 품질 제고와 사용 만족도를 높일 수 있는 가장 효과적인 방안을 설계하여 제안하고자 하였다. 실증연구는 서비스 디자인 관점에서 중국 내의 공유 자전거 서비스 경험자들을 대상으로 더블 다이아몬드 모델（Double diamond model)에 기반을 두고 진행되었다. 연구결과, 공유 자전거의 승차 단계에 대한 유저 교류, 흥미 및 통제권에 대한 수요를 만족시킬 수 있는 새로운 컨셉을 고안하였다. 이 콘셉트에서 제공하는 새로운 서비스 체험 방식은 인간 친화적인 것이 특징이며, 무엇보다도, 공유 자전거 이용자(또는 고객)의 잠재된 니즈를 충족시킬 수 있는 가능성을 보여주었다는 점에서 중요한 의미를 부여할 수 있다.

• 대한건축학회논문집:계획계
• /
• 제34권10호
• /
• pp.83-94
• /
• 2018

In many theoretical and empirical studies on the design issues of therapeutic healthcare facilities, spatial configuration that promotes users' wayfinding behavior, has been emphasized as a significant factor to mitigate stressful experiences and to enhance restorative quality in the healthcare environment. This is also applicable to the healthcare setting for children. However, not much evidence has been reported with regard to the relationship between spatial configuration and wayfinding behaviors in this specific setting. Moreover, healthcare facilities for children with physical disabilities need more attention to provide easy wayfinding due to various physical restrictions. The aim of this study is therefore, to unfold the relationship between spatial configuration and visual cognitive qualities of outpatient spaces in the selected children's rehabilitation hospitals in Seoul, by examining visual cognitive attributes such as visibility, accessibility, and intelligibility. In the first phase, the spatial layout of the hospitals was analyzed, with an emphasis on the major outpatient areas such as the entrance lobby, doctors' examination, and physical therapy zones. In the second phase, a space syntax tool was implemented to examine visual cognitive characteristics of the spatial configuration. The spatial configuration parameters measured were integration, integration core, visual isovist field continuity, correlation between integration and step depth, and the correlation between integration n and integration 3. As a result, the integration was higher in the hall type configuration. Circulation intersections acted mostly as integration cores for better visibility. Some areas showed the lack of continuity in the visual isovist fields overlap and irregular correlation between integration and step depth. The intelligibility was higher in the circulation area and social interaction spaces such as a cafe, reception waiting, and therapy waiting areas. Based on the analysis, design implication and possible future improvement were discussed to enhance wayfinding experiences in the hospitals for children with physical disabilities.

• 대기
• /
• 제33권5호
• /
• pp.561-570
• /
• 2023

In order to improve the predictability of marine high-impacts weather such as typhoon and high waves, the marine observation network is an essential because it could be rapidly changed by strong air-sea interaction. In this regard, the National Institute of Meteorological Sciences, Korea Meteorological Administration (NIMS/KMA) has promoted the Argo float observation program since 2001 to participate in the International Argo program. In this study, current status and future direction of the NIMS/KMA Argo program are presented through the internal meeting and external expert forum. To date, a total of 264 Argo floats have been deployed into the offshore around the Korean Peninsula and the Northwestern Pacific Ocean. The real-time and delayed modes quality control (QC) system of Argo data was developed, and an official regional data assembling center (call-sign 'KM') was run. In 2002, the Argo homepage was established for the systematic management and dissemination of Argo data for domestic and international users. The future goal of the NIMS/KMA Argo program is to improve response to the marine high-impacts weather through a marine environment monitoring and observing system. The promotion strategy for this is divided into four areas: strengthening policy communication, developing observation strategies, promoting utilization research, and activating international cooperation.