• Journal of Sensor Science and Technology
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• v.32 no.2
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• pp.95-99
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• 2023

Forest healing is an activity that enhances immunity and human health using various elements of nature, such as fragrance and scenery. Particularly, phytoncide composed of terpene, a natural volatile substance emitted by forest plants, activates the immune function and is an important raw material in health-related products, such as antibacterial and insect repellents. Moreover, phytoncide is used as a measure to evaluate the impact of the forest atmosphere on the human body. This study aims to implement a highly sensitive gas sensor system that can measure phytoncide in real-time, which is an essential element for realizing a forest healing environment. A gas generation apparatus was implemented by using an adsorption tube in consideration of filed applicability in a laboratory atmosphere to enable the measurement of α-pinene and limonene, which are among the main components of phytoncide. Throughout the experimental trials, the sensitivity of gas sensor arrays to α-pinene and limonene was confirmed. In addition, the classification results demonstrated the AVOCs and NVOCs can be well discriminated using PCA. The primary results confirmed the possibility of developing a high-sensitivity gas sensor system for phytoncide sensing in real time.

• Tribology and Lubricants
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• v.40 no.4
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• pp.118-132
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• 2024

The triboelectric nanogenerator (TENG) has emerged as a groundbreaking technology for harvesting clean and sustainable energy cost effectively. For reliable TENG design, minimizing wear damage at the friction layers is crucial. This review provides a comprehensive overview of tribometer-integrated TENG testing configurations used in the simultaneous investigation of both tribological and electrical performance. It considers configurations such as plate-on-plate, ball-on-disc, and ball-on-flat tribometers designed for linear reciprocating or rotating sliding friction tests. These tribometers are either specifically designed or adapted for TENG testing. Triboelectric material holders facilitate friction tests by establishing electrical connections from the triboelectric materials or electrodes, thereby enabling accurate measurement of electrical signals. Electrometers and oscilloscopes record electrical outputs such as short-circuit current and open-circuit voltage. This integration enables the simultaneous measurement of both friction and electrical outputs, providing a thorough understanding of TENG performance. The review also summarizes how factors such as normal force, sliding frequency, and rotating speed affect friction coefficients and TENG performance. It also examines the relationship between the coefficient of friction and tribocharges under various loads and frequencies. The review emphasizes the importance of these testing configurations for evaluating both friction and electrical performance, which are crucial for optimizing TENG efficiency. Finally, the review explores future prospects for developing innovative tribometer designs suited for both tribology and TENG testing.

• Human Ecology Research
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• v.62 no.3
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• pp.585-599
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• 2024

The purpose of this study was to explore research trends in sleep from infancy through to adolescence. To achieve this, an examination was conducted of sleep research published in Korea based on the publication year, developmental stages of the study participants, research designs, measurement tools, and research topics. A total of 362 academic journal articles and theses/dissertations published in Korea up until 2023 were selected. In terms of publication year, the first study was conducted in 1967 and the field became more active from 2010 onwards. The age group studied the most was adolescents, with cross-sectional research being the most common study design. Regarding sleep measurement tools, most scales measuring sleep in infants, preschoolers, children, and adolescents were developed abroad, then adapted or validated in Korea, or were modifications of adult scales tailored for specific studies. Lastly, in terms of research topics, the most common focus was the relationship between sleep and developmental characteristics, particularly its effects on emotional development. Based on these results, future research could focus on developing sleep-related intervention programs and measurement tools.

• Nuclear Engineering and Technology
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• v.56 no.8
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• pp.2937-2947
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• 2024

The Republic of Korea is performing independent national inspections under the IAEA's State System of Accounting for and Control (SSAC), and developing an evaluation methodology for the material unaccounted for (MUF) to reinforce capabilities with the purpose of assessment for the accounting system of the facility handling bulk nuclear materials. In relation to this, a new approach for MUF evaluation was proposed in this study based on the guide to the expression of uncertainty in measurement (GUM). Both the conventional MUF evaluation method and the GUM method were applied to a hypothetical list of inventory items including material balance. Considering the ease of uncertainty propagation according to the GUM, it was assumed that independent uncertainty factors correspond to random factors, while correlated uncertainty factors correspond to systematic factors. The total MUF uncertainties were similar for both methods; however, it was verified that some uncertainties were affected by the measurement procedure in the GUM method. Furthermore, the GUM method was found to be more conducive to conducting a factor analysis for the MUF uncertainty. It was therefore concluded that application of the GUM approach could be beneficial in cases of national safeguard inspections where factor analysis is required for MUF assessment.

• Journal of Environmental Impact Assessment
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• v.2 no.2
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• pp.1-11
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• 1993

Most developing countries are experiencing rapid urbanization and the associated growth of industry and services. Cities are currently absorbing two-thirds of the total population in the developing world. Korea has about 85 percent of urban dwellers. World population will shift from being predominantly rural to predominantly urban around the turn of the century. Although cities play a key role in development process and make more than a proportionate contribution to national economic growth, especially cities are also the main catalysts of economic growth in developing countries, they can also be unhealthy, inefficient, and inequitable places to live. Most developing countries are increasingly unable to provide basic environmental infrastructure and services, whether in the megacities or in secondary urban centers. Of particular concern is the strain on natural resources brought by the increasing number of people, cars, and factories. They are generating ever greater amounts of urban wastes and emissions. They also exceed the capacity of regulatory authorities to control them and of nature to assimilate them. The environmental consequences are translated into direct negative impacts on human health, the quality of life, the productivity of the city, and the surrounding ecosystems. Environmental degradation threatens the long tenn availability and quality of natural resources critical to economic growth. Cities, with their higher and growing per capita energy use for domestic, industrial, and transport purpose also contribute a disproportionate share of the emission leading to global warming and acid rain. An important priority is to develop strategic approaches for managing the urban environment. The design of appropriate and lasting strategic responses requires first an understanding of the underlying causes of urban environmental deterioration, it is necessary that longer tenn objectives should be set for urban area to avoid irreversible ecological damage and to ensure lasting economic development. As a means to the preventive policies against the adverse effect, environmental impact assessment (EIA) serve to identify a project's possible environmental consequences early enough to allow their being taken into consideration in the decision making process for urban planning. This paper describes some considerations of EIA for urban planning-scoping, assessment process, measurement and prediction of impacts, pollution controls and supervision, and system planning for environmental preservation.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 1998.11a
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• pp.172-177
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• 1998

For making high-functional illumination environment and pleasantness to human beings, it is needed to analyze optical characteristics from lightsource as well as to analyze and examine emotional characteristics which respond to optical characteristics systematically. Also, it is Possible to classify lightsource according to function and use based on optical and emotional characteristics systematically and these results can be applied to practical data for professional illumination design field. The aim of this study is to develop technique for evaluating sensibility as well as to accumulate sensibility database through measuring and evaluating emotional reaction to optical characteristics from lightsource. Final aim of this study is to develop simulation and evaluation technique for interior illumination environment, the outline of this paper : 1) operating simulator for various illumination environment 2) developing evaluation methodology for evaluating illumination environment 3) preparing sensibility index through evaluation and analysis The process of this study is as follows. 1) Developing optical evaluation item of lightsource 2) Developing emotional evaluation item of lightsource 3). Analyzing, correlation between optical evaluation item and emotional eveluation item 4) Classifying and selecting object for evaluation 5) Optical measuring and evaluating for lightsource 6) Operating Simulator for illumination environment 7) Emontional measuring and evaluating lightsource and color 8) Developing estimative formula and sensibility index of emotional reaction The results of this study are as follows. 1. Simulator is operated for various illumination environment, and it is proved to be applicable to actual environment. 2. Evaluation and Analysis Techniques is developed for emotional measurement about illumination environment. 3. Estimative formula and sensibility index are prepared, which can estimate the characteristic of lightsource and emotional reaction to interior color

• Journal of the Korean Association of Geographic Information Studies
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• v.24 no.2
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• pp.78-90
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• 2021

In order to construct a precision geoid, it has been diversified into land, sea, aviation, and satellite gravity measurement methods, and measurement technology has developed, making it possible to secure high-resolution, high-precision gravity data. The construction of precision geoids can be fast and conveniently decided through GNSS surveys without separate leveling, and since 2014, the National Geographic Information Institute has been developing a hybrid geoid model to improve the accuracy of height surveying based on GNSS. In this study, the results of the GNSS height measurement were compared and analyzed choosing existing public reference points to verify the GNSS height measurement of public surveys. Experiments are conducted with GNSS height measurements and analyzed precision for public reference points on coastal, border, and mountainous terrain presented as low-precision areas or expected-to-be low-precision in research reports. To verify the GNSS height measurement, the GNSS ellipsoid height of the surrounding integrated datum to be used as a base point for the GNSS height measurement at the public datum. Based on the checked integrated datum, the GNSS ellipsoid of the public datum was calculated, and the elevation was calculated using the KNGeoid18 model and compared with the results of the direct level measurement elevation. The analysis showed that the results of GNSS height measurement at public reference points in the coastal, border, and mountainous areas were satisfied with the accuracy of public level measurement in grades 3 and 4. Through this study, GNSS level measurement can be used more efficiently than existing direct level measurements depending on the height accuracy required by users, and KNGeoids 18 can also be used in various fields such as autonomous vehicles and unmanned aerial vehicles.

• Journal of Digital Contents Society
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• v.9 no.1
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• pp.101-107
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• 2008

The level of transference of NGN is beginning as the operation of Access Gateway in korea at present, but NGN will keep developing continuously to the NGN integrated network until 2010. This research is finding the meaning and assignment of NGN QoS to deduct how to manage the control system and presenting the QoS control process and trial framework. The trial framework is the modeling of the QoS measurement metrics, the measurement time schedule, the section, hierarchy, instrument, equipment and method of measurement and the series of cycle & the methodology about analysis of the result of measurement. The objective standard of quality in communication service is guaranteed not by itself but by controlling and measuring continuously. Especially it's very important time to maintain the research about NGN QoS measurement and control because the big conversion of new network technology paradigm is now spreading.

• Journal of Sensor Science and Technology
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• v.25 no.2
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• pp.138-142
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• 2016

A pulse measurement by tonometry provides useful information for diagnosis, including not only blood pressure and heart rate but also parameters for estimating a condition of the cardiovascular system. Currently, various pulse measurement devices based on the tonometry have been developed. A reliability of these devices is determined by a positioning technic between the sensor and the blood vessel and a controlling technique of the pressurization level. An angle of the sensor for the pulse measurement seems to be highly related with a measured signal, however, the objective studies for this issue have been not published. In this paper, the variation of the pulse signals by tonometry direction was experimentally assessed according to the angle of the sensor. In order for guaranteeing the repeatability of the experiment, we used a pulse generator device, which can generate human pulse signal by using silicon tube and fluid pump, and developed a structure for precise adjustment of the angle and the pressurization level of the sensor. The angle of the sensor was acquired by an inclinometer, which was attached at the opposite side of the sensor. As results, a coefficient of variation (CV) of a maximum amplitude (MA) of the pulse wave was largely increased over the angle range of $-9{\sim}9^{\circ}$. Furthermore, the changes of the pulse shape showed different aspects according to the sign of the angle tilted along the blood vessel. It is expected that the results of this study can be helpful for developing more precise pulse measurement devices based on the tonometry and applying in clinic.

• Water for future
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• v.28 no.6
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• pp.183-191
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• 1995

Applying microwave, a velocity measurement system has been developed in order to measure the velocity of stream water surface. It's main purpose is the measurement for high velocity of flood water. It is under the developing stage of experimental measurement system. The microwave surface velocity meter uses Doppler effects of microwave. It consists of a radio frequency(RF) part and that of signal processing. Thr RF part has the function of microwave oscillation, reception of reflected wave, and determination of Doppler frequency, etc. Signal processing designates amplification, fast Fourier transform, etx. Various measuring experiments were performed at bridges and a spillway of Taechong re-regulation dam with the microwave velocity meter. Verification test was also made through water tank of ship model test at Research Institute of Ships and Ocean Engineering. It shows 4% error inherent in A/D converter and additional several percentage errors from measurement circumstance. The measuring ranges are from 0.5 to 3.5 m/s. The result shows good linear relationship between carriage velocity and measured velocity, thus proves usefulness as a measuring instrument for flood water velocity. The instrument requires overall re-engineering procedure and number of data should be accumulated and analyzed to treat wind effects and random fluctuations of water surface.