• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.11
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• pp.2485-2490
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• 2010

In this paper, gather the sleep environment data of bedroom to sleeping and analyze the relationship between the obtained conditional data and the sleep. Based on this, system provide the optimal sleep environment of individual person by extracting the simulation model. The experiments of system was using H-MOTE2420 sensor composed of temperature/humidity sensor and ambient light sensors. We use difference image method in motion extraction from video for extraction of tossing and turning. In addition, it was entered such as ratio of fatigue, ratio of drinking, ratio of empty stomach as the information of weight can affect to sleep. Resultingly of experience, we can extract the optimal sleep environment. From now on, we will try to enhance to help to lead more pleasant daily life providing proper indoor environment changes depending on the situation even a partial of organic living environments such as eating and work as well as special sleep circumstances.

• Journal of Oriental Medical Thermology
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• v.4 no.1
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• pp.54-60
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• 2005

Object: A study on the changes of superficial temperature as the ambient temperature varies. Method: After performing research on the physiologic mechanism of heat loss from skin, heat transfer to skin and heat productions of body, the conclusions would be drawn from experiments on temperature changes in every parts of the body as ambient temperature varies . Result and conclusion: Superficial temperature is in equilibrium with ambient temperature after a certain period. Part of the body with big change in superficial temperature tends to have slower temperature change and longer time for adaptation than the part with small change in superficial temperature. The temperature difference between left and right side of the body needs no attention. If adequate adaptation time, a short-period living supervision prior to measurements and appropriate indoor environment management are provided, meaningful conclusion would be attained for infrared thermal diagnosis.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.5
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• pp.2054-2060
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• 2011

The purpose of this paper is to investigate spray characteristics of GDI injector that is economic and environment-friendly. Injector characteristics such as penetration length, spray angle and mixture formation were measured using experimental visualization technique. Especially, it has been analyzed that the influences of ambient pressure and injection pressure on penetration length and spray angle. To visualize the spray, a constant volume combustion chamber and fuel supply system have been manufactured. A high-speed camera and LED light source have been applied to obtain spray images. The experimental and visualization result shows that the penetration length is increased as decreasing ambient pressure and/or increasing injection pressure. Also, ambient pressure and injection pressure have minor effect on the spray angle variation.

• Environmental Analysis Health and Toxicology
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• v.29
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• pp.11.1-11.7
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• 2014

Objectives South Korea's air quality standards are insufficient in terms of establishing a procedure for their management. The current system lacks a proper decision-making process and prior evidence is not considered. The purpose of this study is to propose a measure for establishing atmospheric environmental standards in South Korea that will take into consideration the health of its residents. Methods In this paper, the National Ambient Air Quality Standards (NAAQS) of the US was examined in order to suggest ways, which consider health effects, to establish air quality standards in South Korea. Up-to-date research on the health effects of air pollution was then reviewed, and tools were proposed to utilize the key results. This was done in an effort to ensure the reliability of the standards with regard to public health. Results This study showed that scientific research on the health effects of air pollution and the methodology used in the research have contributed significantly to establishing air quality standards. However, as the standards are legally binding, the procedure should take into account the effects on other sectors. Realistically speaking, it is impossible to establish standards that protect an entire population from air pollution. Instead, it is necessary to find a balance between what should be done and what can be done. Conclusions Therefore, establishing air quality standards should be done as part of an evidence-based policy that identifies the health effects of air pollution and takes into consideration political, economic, and social contexts.

• Environmental Analysis Health and Toxicology
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• v.25 no.1
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• pp.27-40
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• 2010

The current study was designed to scientifically evaluate the atmospheric particulate pollution in residences relative to their proximity to a Korean major iron/metal industrial complex (IMIC). This objective was achieved by measuring the concentrations and elemental composition of particulate matter with aerodynamic diameters equal to or less than 10 ${\mu}m$(PM10) in industrial ambient air from IMIC and residential ambient air with relative proximities to IMIC. The trace metals were analyzed using an inductively coupled plasma-atomic emission spectroscopy (ICP-AES). The industrial mean values exceeded the Korean year/70-${\mu}g/m^3$ standard for PM10, whereas the residential mean values did not. However, the maximum residential values did exceed or were close to the Korean PM10 year standard. For individual elements, the ambient concentrations ranged widely from values in the order of a few $ng/m^3$ to thousands of $ng/m^3$. The residential mean mass concentrations in the PM10 measured in the present study were higher than or similar to those reported in earlier studies. This study suggests that residents in neighborhoods near the IMIC are exposedto elevated particulate levels compared to residents living further away from such a source.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2003.10a
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• pp.157-163
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• 2003

A systematic numerical experiment has been conducted to study droplet gasification in high pressure environments with pressure oscillations. The general frame of previous rigorous model[1] is retained but tailored for flash equilibrium calculation of vapor-liquid interfacial thermodynamics. Time-dependent conservation equations of mass, momentum, energy, and species concentrations are formulated in axisymmetric coordinate system for both the droplet interior and ambient gases. In addition, a unified property evaluation scheme based on the fundamental equation of state and empirical methods are used to find fluid thermophysical properties over the entire thermodynamic domain of interest. The governing equations with appropriate physical boundary conditions are numerically time integrated using an implicit finite-difference method with a dual time-stepping technique. A series of calculation have been carried out to investigate the gasification of an isolated n-pentane droplet in a nitrogen gas environment over a wide range of ambient pressures and frequencies. Results show that the mean pressures and frequencies of the ambient gas have strong influences on the characteristics of the droplet gasification. The amplitude of the response increases with increasing pressure, and the magnitude of the vaporization response increases with the frequency.

• Journal of Ecology and Environment
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• v.38 no.3
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• pp.335-342
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• 2015

This research was conducted to examine the changes in growth and production of Oryza sativa L. cv. Ilmi, which was developed to cultivate high yielding rice variety in the Southern plains of Korea. The seedlings of the rice were cultivated from May to October in 2012 under three different conditions: control, AC-AT, ambient $CO_2$ + ambient temperature; AC-ET, ambient $CO_2$ + elevated temperature; EC-ET, elevated $CO_2$ + elevated temperature. The aboveground biomass, belowground biomass, the total biomass of the rice, and panicle weight per individual were the heaviest in the EC-ET. But, the number of grains per panicle and the weight of one grain was higher at the condition of AC-ET and EC-ET than that of AC-AT. The number of tiller was higher at the condition of AC-AT and AC-ET than that of EC-ET. However, there was no significant difference in the number of panicles per individual and the ripened grain rate among the control and global warming treatments. Crop yield was the highest in the EC-ET. This result means that the global warming condition should be considered in the selection of suitable paddy field for the limibyeo in the future.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.8
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• pp.1246-1250
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• 2015

The purpose of this paper is to investigate the autonomic nervous system activity in various ambient temperature situation. To evaluate autonomic function, we use the time domain analysis of heart rate variability. Electrocardiogram was recorded to derive heart rate variability in 3 different temperature room which temperature is controlled in 18℃(low), 25℃ (mid) and 38℃(high), respectively. Totally 22 subjects were participated in the experiment. The result shows that the time-domain variables such as AVNN, SDNN, SDSD, RMSSD, NN50, pNN50, NN20 and pNN20 show the significant difference between low and high temperature (p<0.01). However, these variables has no significance (p>0.05) between mid and high except on AVNN, RMSSD and pNN20. AVNN, RMSSD shows the highest significance (p<0.001) according to the various temperature environment.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.03a
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• pp.255-259
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• 2008

This paper presents the spray characteristics of the oxidizer rich preburner injector which can be used in the high-thrust rocket system. We designed the basic shape of the liquid-liquid coaxial swirl injector for the rocket oxidizer rich preburner injection system. To understand the spray angle variation with the high pressure environment, the spray visualization in the high pressure chamber was preformed. Also we measured the droplet velocity, the Sauter Mean Diameter(SMD), the volume flux and the number density with the PDPA system by using water in atmospheric pressure. The results show that the spray angle is reduced by increasing ambient pressure and maximum droplet velocity is shown from a nozzle tip and then the droplet velocity decreases as a spray moves to the downstream. The SMD decreases on the axial distance from 20 mm to 50 mm but it increases over 50 mm. That is due to the increasing number of collision with each droplet and interaction with ambient air on going downstream direction.

• Advances in concrete construction
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• v.5 no.1
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• pp.17-29
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• 2017

Geopolymer concrete is environmentally friendly and could be considered as a construction material to promote the sustainable development. In this paper fly ash based geopolymer concretes with different percentages of alccofine were made by mixing sodium hydroxide and sodium silicate as an alkaline activator and cured at ambient as well as heat environment in an electric oven at $90^{\circ}C$. Effects of various parameters such as the percentage of alccofine, curing temperature, a period of curing, fly ash content, was studied on compressive strength as well as workability of geopolymer concrete. The study concludes that the presence of alccofine improves the properties of geopolymer concrete during a fresh and hardened state of concrete. Geopolymer concrete in the presence of alccofine can be used for the general purpose of concrete as required compressive strength can be achieved even at ambient temperature. The 28 days compressive strength of 73 MPa, when cured at 90-degree Celsius, confirmed that it is also very suitable for precast concrete components.