• Korean Journal of Applied Biomechanics
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• v.28 no.2
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• pp.127-134
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• 2018

Objective: In a statistical linear model estimating the center of rotation of a human hip joint, which is the parameter related to the mean of response vectors, assumptions of homoscedasticity and independence of position vectors measured repeatedly over time in the model result in an inefficient parameter. We, therefore, should take into account the variance-covariance structure of longitudinal responses. The purpose of this study was to estimate the efficient center of rotation vector of the hip joint by using covariance pattern models. Method: The covariance pattern models are used to model various kinds of covariance matrices of error vectors to take into account longitudinal data. The data acquired from functional motions to estimate hip joint center were applied to the models. Results: The results showed that the data were better fitted using various covariance pattern models than the general linear model assuming homoscedasticity and independence. Conclusion: The estimated joint centers of the covariance pattern models showed slight differences from those of the general linear model. The estimated standard errors of the joint center for covariance pattern models showed a large difference with those of the general linear model.

• Journal of radiological science and technology
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• v.41 no.6
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• pp.533-538
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• 2018

As the use of digital radiographic system has been expanded, there are some concerns an increase about in patient of radiation dose. Therefore, International Electro-technical Commission (IEC) has been proposed a standard foe exposure index (EI). In this study, the EI was measured on human chest model using computed radiography (CR). Radiation quality used RQA5 of IEC62494-1. After acquiring the chest anterior posterior image (Chest AP) by using the phantom, the EI was obtained by applying the system response. In this study, we have analyzed the images with the detector size (Full filed ROI) and the optimized image (Fit filed ROI). The EI increased proportionally with radiation dose increase. Due to the discrete increase in pixel value, the EI showed an exponential increase. The discrete increase in noise equivalent quanta (NEQ) resulted in a discrete increase in the EI. The EI of the two images used in this study increased with increasing NEQ but showed different increments. For the measurement of the EI, IEC standards must be followed. The EI should be used as an index to evaluate the image quality for quality control of X-ray image rather than as an indicator of exposure dose. When calculating the EI, the system response should be applied depending on whether or not the grid is used. The size of the field should be obtained by including only the necessary parts.

• The Korean Journal of Ecology
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• v.24 no.5
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• pp.323-332
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• 2001

A cultural landscape results from a combination of human activities for resource-use and the response of nature to such artificial interference. Nature provides resources necessary for human life on the Earth in terms of his survival as well as living. Humanbeing has developed civilization using the benefits that nature provides. In the past, a harmonious relationship between mankind and nature had ensured sustainability of resource-use for human. We can find such facts from the existence of cultural landscape. However, rapid economic growth and a development-oriented logic caused from such socio-economic change led to the environmental crises and the depletion of various resources at global level. In the perspective of preparation for such problems, we investigated the background for establishment, function, and value of cultural landscapes, in which a dynamic equilibrium exists between a supply of natural resources and human needs. Furthermore, we discussed a new economic model including ecological consideration, a strategy for ecological management of environment, and a framework for transmission of traditional culture to new generations on the basis of a cultural landscape regime.

• Journal of Environmental Impact Assessment
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• v.10 no.3
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• pp.211-221
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• 2001

Recognizing interaction between the environment and humans, the EIA(environmental impact assessment) movement has sought to promote more environmentally sound and informed decisions for the sake of human welfare. Therefore, most EIA programs require the consideration of human health impacts. Yet relatively few EIA documents adequately address those impacts. This study was carried out to investigate the role of EIA for reuniting the environment and human health, for preventing and reducing significant health risks, and for improving human health impact assessment by means of risk assessment. Risk assessment consists of 4 components; hazard identification, dose-response assessment, exposure assessment and risk characterization. Since most people spent their times in indoor, indoor air quality modelling can be used in exposure assessment and risk assessment. In this study, indoor $NO_2$ concentration and personal $NO_2$ exposure were estimated by Box Model using mass balance equation and time weighted average, respectively. The estimated indoor $NO_2$ concentration and the personal $NO_2$ exposure were compared by those measured, respectively. Subsequntly, health effect was assessed with these results. Consequently, exposure assessment and risk assessment using indoor air quality model may be considered to be applicable to EIA.

• The Korean Journal of Physiology and Pharmacology
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• v.1 no.6
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• pp.691-697
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• 1997

The mechanisms underlying opiate tolerance and dependence are not fully understood. We used human neuroblastoma SH-SY5Y cells as a model system for studying effects of morphine tolerance and withdrawal on c-myc induction and cAMP levels. It has been reported that regulation of c-fos by acute and chronic morphine withdrawal is mediated through alterations in CREB transcription factor. In this study, we examined the effects of morphine tolerance on c-myc expression and cAMP concentrations. The activation of opiate receptors by an acute morphine administration resulted in an increase in c-myc mRNA and a decrease in cAMP concentrations in a dose-dependent manner $(5,\;10,\;15,\;and\;20\;{\mu}M)$. On the other hand, the chronic treatment of morphine $(10\;{\mu}M\;for\;six\;days)$ did not induce the elevated expression of c-myc mRNA. The c-myc expression was slightly inhibited in comparison with that of the acute morphine response. However, cAMP concentrations were increased with regard to morphine withdrawal response. These results suggest that the alterations in c-myc expression might imply a significant opiate regulation relating to morphine tolerance. This observation differs from increased expression of c-fos via regulation of cAMP pathway.

• International Journal of High-Rise Buildings
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• v.1 no.1
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• pp.15-19
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• 2012

Occupant footfalls are often the most critical source of floor vibration on upper floors of buildings. Floor motions can degrade the performance of imaging equipment, disrupt sensitive research equipment, and cause discomfort for the occupants. It is essential that low-vibration environments be provided for functionality of sensitive spaces on floors above grade. This requires a sufficiently stiff and massive floor structure that effectively resists the forces exerted from user traffic. Over the past 25 years, generic vibration limits have been developed, which provide frequency dependent sensitivities for wide classes of equipment, and are used extensively in lab design for healthcare and research facilities. The same basis for these curves can be used to quantify acceptable limits of vibration for human comfort, depending on the intended occupancy of the space. When available, manufacturer's vibration criteria for sensitive equipment are expressed in units of acceleration, velocity or displacement and can be specified as zero-to-peak, peak-to-peak, or root-mean-square (rms) with varying frequency ranges and resolutions. Several approaches to prediction of floor vibrations are currently applied in practice. Each method is traceable to fundamental structural dynamics, differing only in the level of complexity assumed for the system response, and the required information for use as model inputs. Three commonly used models are described, as well as key features they possess that make them attractive to use for various applications. A case study is presented of a tall building which has fitness areas on two of the upper floors. The analysis predicted that the motions experienced would be within the given criteria, but showed that if the floor had been more flexible, the potential exists for a locked-in resonance response which could have been felt over large portions of the building.

• Korean Journal of Community Nutrition
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• v.16 no.6
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• pp.771-781
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• 2011

The objective of this study was to assess the reliability and validity of food security measures, which was developed based on the US household food security survey module (US HFSSM) with content validity in the Korean population. The reliability and validity were assessed by internal consistency, construct validity and criterion-related validity. The study included 446 households. Among those, 46.2% were households with children. The proportion of food insecure households was 33.3%. Among those, 35.4% and 64.6% households were food insecure with hunger and without hunger, respectively. The Cronbach's alpha coefficients were 0.84 and the infit value by the Rasch model analysis ranged from 0.68 to 1.43. The scale item response curves by food insecurity severity explained well the nature and characteristics of food security, indicating the highest proportion of "yes" for the items on diet quality, followed by those with diet quantity. The result of criterion-related validity showed that food insecurity status was significantly related in a dose-response manner with the household income level, food expenditure, subjective health state, subjects' educational level. Household food security status was also related to dietary diversity regarding protein foods, fruits and fruit juice, and milk and dairy product. These findings suggest that the food security instrument is reliable and valid and would be used to assess food security status in the Korean population.

• Journal of the Korean Association of Geographic Information Studies
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• v.5 no.1
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• pp.69-79
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• 2002

The more people and urban infrastructures are crowded in a society, the more possibilities of disasters are existed. Most of cities have a difficulty in coping with unpredictable disasters consisting of natural and human characteristics. As a proved before, theses disasters have serious effects on socio-economical, financial and physical damages, and human lives. Although we have prepared various types of disaster-protection programs, there are rooms to be desired in establishing advanced warning system towards safeguards of disasters. In this research, we propose semantic ideas of an advanced information system associated with automatic voicing mail linking to telephone. This conceptual model and its architecture is for not only predicting and analyzing disasters, but also recommending counter-measurements and solutions for risks and dangers in disastrous circumstances. However, there are little works with regard to definitions and conceptual models of automatic voicing mail system in the context of geographical information sciences. Therefore, this research focuses on scrutinizing the effect of possible natural vulnerability and human hazards in our present societies.

• Journal of The Geomorphological Association of Korea
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• v.25 no.1
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• pp.97-113
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• 2018

Low-frequency geological natural disaster events such as Pohang earthquake have been occurred. As a results, there's a growing recognition on the importance of education and training for low frequency geological disasters in Korea. In spite of many years of scientific researches on volcanic disaster prevention and preparedness on Baekdusan volcano, the results do not provide the proper scenario for the training for volcanic ash event. Fall 3D volcanic ash diffusion model was run based on wind field data for the last five year, assuming Aso Mountain's explosion with volcanic explosion index 5 for seventy two hours. The management criteria values for proper actions in the previous studies were applied to make a scenario for thirteen groups of the disaster response teams such as train transportation, water supply, electrical facilities and human health. The models on the relationship between education and training for disaster prevention and response were suggested to fulfill the scientific and practical training at local level.

• Journal of Multimedia Information System
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• v.5 no.3
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• pp.209-214
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• 2018

Today is the era of artificial intelligence. With the development of artificial intelligence, machines have begun to impersonate various human characteristics today. Chatbot is one instance of this interactive artificial intelligence. Chatbot is a computer program that enables to conduct natural conversations with people. As mentioned above, Chatbot conducted conversations in text, but Chatbot, in this study evolves to perform commands based on speech-recognition. In order for Chatbot to perfectly emulate a human dialogue, it is necessary to analyze the sentence correctly and extract appropriate response. To accomplish this, the sentence is classified into three types: objects, actions, and preferences. This study shows how objects is analyzed and processed, and also demonstrates the possibility of evolving from an elementary model to an advanced intelligent system. By this study, it will be evaluated that speech-recognition based Chatbot have improved order-processing time efficiency compared to text based Chatbot. Once this study is done, speech-recognition based Chatbot have the potential to automate customer service and reduce human effort.