• 한국재난관리표준학회지
• /
• 제1권2호
• /
• pp.61-66
• /
• 2008

국토의 70% 이상이 산지로 구성되어 있어서 도로와 철도 건설을 위해 절토사면이 필연적으로 발생한다 우기, 동절기 서리로 인한 지반융기, 그리고 해빙은 암석 탈락과 사면붕괴의 원인이 되며 매년 사면붕괴에 의한 차량파손과 인명피해가 증가하고 있다. 인명과 재산을 보호하기 위해 사연붕괴를 조기에 탐지할 수 있는 실시간 모니터링 시스템이 필요하다. GMG사에서 개발한 병진 회전 침하(TRS) 센서를 사면 내에 설치하여 실시간으로 사면을 모니터링을 할 수 있도록 했으나, 시스템의 데이터 획득체계가 취약하여 순간적인 낙뢰에 의해 전체 시스템이 손상될 수 있다. 따라서 저자들은 USN(Ubiquitous Sensor Network)을 제시하여 낙뢰에 의한 손상을 최소화시키고 신뢰도 높은 사면 변형 모니터링 체계를 구축했다.

• 보건행정학회지
• /
• 제27권4호
• /
• pp.284-295
• /
• 2017

Background: The objectives of this study were to identify the reasons of quitting smoking, to determine the factors that make it difficult or helpful to maintain smoking cessation and to confirm the changes after the smoking cessation. Methods: This study was conducted an in-depth interview with people who participated in the smoking cessation treatment program. There were 10 participants and they were interviewed thoroughly for 14 times. Using the directed content analysis, we analyzed the transcript which was written by recording the interview and the researchers' note. Results: The results of this study are summarized as 'the experience while at the verge of smoking cessation and stepping over the verge of smoking cessation,' 'the changing experience due to smoking cessation,' and 'maintaining the changes through overcoming re-smoking.' The smoking cessation treatment program induced the smokers to quit smoking. Participants mentioned drinking alcohol was the major obstacle to maintain smoking cessation. Also, they noted that the money and the time that were already spent to quit smoking helped their smoking cessation as well as the social relations which helped to prevent re-smoking. Participants felt well-cared through the smoking cessation treatment program and that it helped them to maintain smoking cessation. Conclusion: Smoking cessation treatment program has a positive effect on the smoking cessation trial and maintenance. In order for smokers to overcome re-smoking, educations regarding drinking problem, formation of supportive social relationship, and the applications for smoking cessation will be beneficial.

• Molecules and Cells
• /
• 제41권4호
• /
• pp.362-372
• /
• 2018

High mobility group box 2 (HMGB2) is an abundant, chromatin-associated, non-histone protein involved in transcription, chromatin remodeling, and recombination. Recently, the HMGB2 gene was found to be significantly downregulated during senescence and shown to regulate the expression of senescent-associated secretory proteins. Here, we demonstrate that HMGB2 transcription is repressed by p21 during radiation-induced senescence through the ATM-p53-p21 DNA damage signaling cascade. The loss of p21 abolished the downregulation of HMGB2 caused by ionizing radiation, and the conditional induction of p21 was sufficient to repress the transcription of HMGB2. We also showed that the p21 protein binds to the HMGB2 promoter region, leading to sequestration of RNA polymerase and transcription factors E2F1, Sp1, and p300. In contrast, NF-Y, a CCAAT box-binding protein complex, is required for the expression of HMGB2, but NF-Y binding to the HMGB2 promoter was unaffected by either radiation or p21 induction. A proximity ligation assay results confirmed that the chromosome binding of E2F1 and Sp1 was inhibited by p21 induction. As HMGB2 have been shown to regulate premature senescence by IR, targeting the p21-mediated repression of HMGB2 could be a strategy to overcome the detrimental effects of radiation-induced senescence.

• 경영정보학연구
• /
• 제7권2호
• /
• pp.163-181
• /
• 2005

본 연구에서는 MRO e마켓의 성공 요소를 엔투비(주)의 사례를 바탕으로 제시하였다. e마켓의 성공요소를 초기 유동성, 공급자 참여, 구매자 참여, 중개자 가치 기여로 분류하고 이를 바탕으로 비즈니스 모델의 실천적 요소를 엔투비의 창업부터 성장 과정의 분석을 통하여 정리하였다. 본 연구의 특징은 성공적인 e마켓 구현을 위한 실천적 변화관리 요소를 장애 요인 및 비즈니스 모델 관점에서 제시한데 있다. 비즈니스 모델 구성 요소, 가치 구조, 전자 카탈로그 등을 상세히 제시하였고 MRO e마켓활용을 통한 고객사의 성과 개선은 사용자 직접구매(Desktop Purchasing) 및 전자조달 프로세스를 통한 계량적 직간접 비용 절감 효과를 예시하였다. 본 연구의 공헌은 e마켓의 이론 대비 상대적으로 부족한 실천적 연구의 간격을 좁힌데 있으며 본 사례 연구를 통하여 제시된 시사점은 MRO e마켓의 성공적 구현을 위한 향후 연구에 활용될 수 있다.

• 경영정보학연구
• /
• 제4권1호
• /
• pp.89-110
• /
• 2002

오늘날 대학은 지식 및 정보혁명에 대응하여 새로운 가상학습모델(가상대학, E-Learning)의 도입과 같은 교육 패러다임의 변화기에 놓여 있다. 이러한 변화기에 가상대학은 분명 대학에게 새로운 기회와 위협을 주고 있다. 만일 대학이 가상학습모델의 지원을 위한 가상대학시스템을 구축하고, 이를 미래의 중요한 전략적 요소로 인식한다면 가상대학시스템은 대학의 입장에서 볼 때 중요한 전략적 정보시스템이 될 수 있다. 본 연구에서는 가상대학시스템을 대학의 중요한 전략정보시스템으로 인지하고 이에 대한 체계적인 전략계획수립을 위한 하나의 프레임웍을 제시하며, 가상대학시스템 전략수립에 있어 가장 큰 영향력을 가진 집단인 교수자의 의견과 요구사항을 분석하여 이들의 요구가 가상대학 전략수립에 어떻게 반영되어야 할 것인지를 제시하고자 한다.

• 오토저널
• /
• 제3권1호
• /
• pp.61-68
• /
• 1981

There are three types in frequency response accelerometer; one is lightly damped piezp type, another is oil damping stainguage type and the third is electro induction type accelerometer within electromagnetic damping. The usable frequency range of lightly damped accelerometers is limited to 0.2 of their mounted natural frequency for amplitude distortion of less than 5 percents. There have been situation where the measured motion contains unforeseen high - frequency components, which are regarded as such due to the accelerometer transfer function. There are several way to overcome amplitude distortion of the higher than anticipated frequency components; (I) to make use of the accelerometer with natural frequency three times and more as high as the measured frequency, (II) to establish data-analysis techniques which will account for the amplitude distortion, (III) to set up a notch filter circuit which has a transfer function that is the reciprocal of the accelerometer transfer function, and so on. This paper makes a report of the method as to(III), i. e., set up a few notch filter circuits, it is discussed what happens when the transfer functions, are in discord as to natural frequency of the filter and accelerometer damping vs. filter damping. And especially as for the cantilever strain gauge type accelerometer made by oneself with ease, it was compared and discussed between the ideological value and the experimental value of actual designed circuit in case of the mismatching of the transfer functions, and it was considered whether to be practicable or not, the result of which was as following; the useful frequency range of the accelerometer can be extended to near resonance if (a) the accelerometer mounted natural frequency and the filter center frequency are matched within .+-. 2 percent and (b) the damping ratios are matched within two factors. Therefore, we obtained the good result in improvement for extending frequency response characteristics of accelerometer.

• 한국산업보건학회지
• /
• 제18권2호
• /
• pp.149-160
• /
• 2008

Bag-filter system has been widely used in industrial field to remove the particulate matters from the exhaust gas. The cylindrical type of bag-filter has been generally used. But it has many shortcomings. The reattachment of separated particles on the surface of bags could result in high pressure drop of bag-filter system and subsequent decrease of air flow rate since the cylindrical type bag-filter system should have the upward flow pattern. In addition, the supply of very high pressure pulse air jet to remove particulate matters on the surface of filter could result in a frequent rupture of bags. To overcome these shortcomings of the cylindrical type, the rectangular type was developed in the developed countries and imported to Korea. But, there was not many design data available to understand the mechanisms. Thus, the fundamental experiments were conducted in this study to get some ideas about the pulse jet cleaning of rectangular type bag filter system. The experimental factors are as follows; pulse distance, pulse duration, pulse interval, pulse pressure and pulse nozzle type. Experiments followed the factorial design method. With the shorter pulse distance, the distribution of pressure drops was relatively not uniform while the particulate removal efficiency was higher. With the longer duration of pulsing and the more number of pulse nozzle, the removal efficiency was higher and the pressure drop distribution was more uniform.

• 한국식물생명공학회:학술대회논문집
• /
• 한국식물생명공학회 2002년도 추계학술대회
• /
• pp.49-58
• /
• 2002

Oxidative stress derived from reactive oxygen species (ROS) is one of the major damaging factors in plants exposed to environmental stress. In order to develop the platform technology to solve the global food and environmental problems in the 21s1 century, we focus on the understanding of the antioxidative mechanism in plant cells, the development of oxidative stress-inducible antioxidant genes, and the development of transgenic plants with enhanced tolerance to stress. In this report, we describe our recent results on industrial transgenic plants by the gene manipulation of antioxidant enzymes. Transgenic tobacco plants expressing both superoxide dismutase (SOD) and ascorbate peroxidase (APX) in chloroplasts were developed and were evaluated their protection effects against stresses, suggesting that simultaneous overexpression of both SOD and APX in chloroplasts has synergistic effects to overcome the oxidative stress under unfavorable environments. Transgenic tobacco plants expressing a human dehydroascorbate reductase gene in chloroplasts were showed the protection against the oxidative stress in plants. Transgenic cucumber plants expressing high level of SOD in fruits were successfully generated to use the functional cosmetic purpose as a plant bioreactor. In addition, we developed a strong oxidative stress-inducible peroxidase promoter, SWPA2 from sweetpotato (Ipomoea batatas). We anticipate that SWPA2 promoter will be biotechnologically useful for the development of transgenic plants with enhanced tolerance to environmental stress and particularly transgenic cell lines engineered to produce key pharmaceutical proteins.

• 한국임상수의학회지
• /
• 제28권4호
• /
• pp.422-426
• /
• 2011

For a national survey in which wide geographic region or an entire country is targeted, multi-stage sampling approach is widely used to overcome the problem of simple random sampling, to consider both herd- and animallevel factors associated with disease occurrence, and to adjust clustering effect of disease in the population in the calculation of sample size. The aim of this study was to establish sample size for estimating bovine tuberculosis (TB) in Korea using stratified two-stage sampling design. The sample size was determined by taking into account the possible clustering of TB-infected animals on individual herds to increase the reliability of survey results. In this study, the country was stratified into nine provinces (administrative unit) and herd, the primary sampling unit, was considered as a cluster. For all analyses, design effect of 2, between-cluster prevalence of 50% to yield maximum sample size, and mean herd size of 65 were assumed due to lack of information available. Using a two-stage sampling scheme, the number of cattle sampled per herd was 65 cattle, regardless of confidence level, prevalence, and mean herd size examined. Number of clusters to be sampled at a 95% level of confidence was estimated to be 296, 74, 33, 19, 12, and 9 for desired precision of 0.01, 0.02, 0.03, 0.04, 0.05, and 0.06, respectively. Therefore, the total sample size with a 95% confidence level was 172,872, 43,218, 19,224, 10,818, 6,930, and 4,806 for desired precision ranging from 0.01 to 0.06. The sample size was increased with desired precision and design effect. In a situation where the number of cattle sampled per herd is fixed ranging from 5 to 40 with a 5-head interval, total sample size with a 95% confidence level was estimated to be 6,480, 10,080, 13,770, 17,280, 20.925, 24,570, 28,350, and 31,680, respectively. The percent increase in total sample size resulting from the use of intra-cluster correlation coefficient of 0.3 was 22.2, 32.1, 36.3, 39.6, 41.9, 42.9, 42,2, and 44.3%, respectively in comparison to the use of coefficient of 0.2.

• 제어로봇시스템학회논문지
• /
• 제6권12호
• /
• pp.1113-1119
• /
• 2000

To operate a process plant safely and economically, process monitoring is very important. Process monitoring is the task to identify the state of the system from sensor data. Process monitoring includes data acquisition, regulatory control, data reconciliation, fault detection, etc. This research focuses on the data recon-ciliation using scale-space filtering and fault detection using functional-link associative neural networks. Scale-space filtering is a multi-resolution signal analysis method. Scale-space filtering can extract highest frequency factors(noise) effectively. But scale-space filtering has too large calculation costs and end effect problems. This research reduces the calculation cost of scale-space filtering by applying the minimum limit to the gaussian kernel. And the end-effect that occurs at the end of the signal of the scale-space filtering is overcome by using extrapolation related with the clustering change detection method. Nonlinear principal component analysis methods using neural network have been reviewed and the separately expanded functional-link associative neural network is proposed for chemical process monitoring. The separately expanded functional-link associative neural network has better learning capabilities, generalization abilities and short learning time than the exiting-neural networks. Separately expanded functional-link associative neural network can express a statistical model similar to real process by expanding the input data separately. Combining the proposed methods-modified scale-space filtering and fault detection method using the separately expanded functional-link associative neural network-a process monitoring system is proposed in this research. the usefulness of the proposed method is proven by its application a boiler water supply unit.