• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.18 no.1
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• pp.57-60
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• 2008

Since human listening is very sensitive to sound, for evaluating of a sound quality is required. Therefore, in the analysis for each situation, the sound evaluation is composed with sound quality factor. My researchers spends their effort to make a more reliable and more accurate of sound in term of sound quality index for various system noise. The previous methods to evaluation of the SQ about vehicle interior noise are linear regression analysis of subjective SQ metrics by statistics and the estimation of the subjective SQ values by neural network. But these are highly dependent on jury test and have many difficulties due to various environmental factors. So, to reduce jury test weight. we suggested a new method using Mahalanobis distance for SQ evaluation. Threrefore, in this study Mahalanobis distance for the vehicle interior noise was derived using the objective SQ except jury test. Finnaly, the results of the SQ evaluation was analyzed discrimination between reference and abnormal group.

• Journal of Drive and Control
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• v.13 no.2
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• pp.1-9
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• 2016

In this paper, an elementary force fighting problem was investigated. The problem is encountered when a double-rod type EHA(electro-hydrostatic actuator) is combined with a single-rod type EHA to build a redundant actuator system with synchronized motion. When the rod-side chambers of the two different types of EHAs have the same effective piston areas and are simultaneously pressurized by an external load, the two EHAs behave identically, sharing the external load equally. However, when the piston head-side chamber of the single rod type EHA, having a larger effective area than the rod-side chamber, is pressurized by the external load, an abnormal force fighting between the two EHAs occurs, unless their pump speeds are properly decoupled. In this study, the output drive forces of each EHA were obtained from the cylinder pressure signals and applied to the position control for each EHA to maintain the balance between their pump speeds. Adding minor force difference feedback loops to the position control, the force fighting phenomena could be eliminated and steady state synchronization errors were reduced. The power consumption of the pumps also could be remarkably reduced, avoiding unnecessarily high load pressures to the pumps.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.35 no.3
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• pp.133-144
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• 2017

Recently, weather information is getting closer to our real life, and it is a very important factor especially in the transportation field. Although the damage caused by the abnormal climate changes around the world has been gradually increased and the correlation between the road risk and the possibility of traffic accidents is very high, the domestic research has been performed at the level of basic research. The Purpose of this study is to develop a risk map for the road hazard forecasting service of weather situation by linking real - time weather information and traffic information based on accident analysis data by weather factors. So, we have developed a collection and analysis about related data, processing, applying prediction models in various weather conditions and a method to provide the road hazard map for national highways and provincial roads on a web map. As a result, the road hazard map proposed in this study can be expected to be useful for road managers and users through online and mobile services in the future. In addition, information that can support safe autonomous driving by continuously archiving and providing a risk map database so as to anticipate and preemptively prepare for the risk due to meteorological factors in the autonomous driving vehicle, which is a key factor of the 4th Industrial Revolution, and this map can be expected to be fully utilized.

• Korean Journal of Clinical Laboratory Science
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• v.47 no.4
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• pp.216-224
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• 2015

This study aims to identify the prevalence of sleep related disease in those who experienced car accidents caused by drowsy driving. To this end, a survey of usual sleep habits, polysomnography, and multiple sleep latency tests were conducted in 34 persons who experienced an accident after normal sleep (Group 1), 22 persons who experienced an accident after abnormal sleep (Group 2), and 17 persons who was proven to be normal as a result of polysomnography and had no accident (Group 3). In all, 192 persons responded to the preliminary survey and the results were compared and analyzed. Crossover analysis was conducted to test the homogeneity of statistical characteristics, and the physical characteristics by age were analyzed. In the survey of sleeping habits, there was a significance between groups in how often they woke up while asleep (p<0.01), how difficult it was to go back to sleep again after waking up from sleep (p<0.05), how early they woke up in the morning (p<0.05), how difficult it was to get up in the morning (p<0.05), how sleepy they felt in the daytime (p<0.01), and how tired they felt in the daytime (p<0.01). Furthermore, among 56 subjects who had an accident during drowsy driving, 94.6% (53 persons) were found to have sleep related diseases. This suggests that car accidents during drowsy driving is not simply caused by temporary lack of sleep but by sleep related diseases even when sleep is adequate, leading to car accidents. Therefore, this study is significant identifying the association between car accidents during drowsy driving and sleep related disorders. Furthermore, the data would be considered basic to prepare social measures against drowsy driving related to such sleep related disorders.

• Journal of Korea Spatial Information System Society
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• v.10 no.3
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• pp.55-65
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• 2008

For obtaining telematics traffic information(travel time or speed in an individual link), there are many kinds of devices to collect traffic data. Since the GPS satellite signals have been released to civil society, thank to the development of GPS technology, the GPS has become a very useful instrument for collecting traffic data. GPS can reduce the cost of installation and maintenance in contrast with existing traffic detectors which must be stationed on the ground. But. there are Problems when GPS data is applied to the existing filtering techniques used for analyzing the data collected by other detectors. This paper proposes a method to provide users with correct traffic information through filtering abnormal data caused by the unusual driving in collected data based on GPS. We have developed an algorithm that can be applied to real-time GPS data and create more reliable traffic information, by building patterns of past data and filtering abnormal data through selection of filtering areas using Quartile values. in order to verify the proposed algorithm, we experimented with actual traffic data that include probe cars equipped with a built-in GPS receiver which ran through Gangnam Street in Seoul. As a result of these experiments, it is shown that link travel speed data obtained from this algorithm is more accurate than those obtained by existing systems.

• Journal of Service Research and Studies
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• v.11 no.2
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• pp.118-130
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• 2021

This study designs and validates a greenhouse complex environmental control algorithm with a multi-phase processing scheme that can combine and control actuators according to the degree of change in the greenhouse environment. The composite environmental control system is a system in which the complex environmental controller analyzes the information detected by sensors and operates appropriately actuators to maintain the crop growth environment. A composite environmental controller directs control devices driving actuators through a composite environmental control algorithm, which calculates the values necessary for the operation of the control devices. Most existing algorithms carry out control procedures on a single phase by iteration cycle, which can cause abnormal changes in the greenhouse environment due to errors in output. The proposed algorithm distributes control procedures over multiple phases: environmental control, environmental control, and device operation, and every iteration cycle, detects environmental changes in the environmental control phase first, and then combines control devices that can control the environment in the environmental control phase, and finally, performs the controls to derive the actuators in the device operation phase. The proposed algorithm is designed based on the analysis of the relationship between greenhouse environmental elements and control devices deriving actuators. According to verification analysis, the multi-phase processing scheme provides room to modify or supplement the setting value and enables the control devices to reflect changes in the associated environmental components.

• Journal of the Korean Society of Radiology
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• v.7 no.1
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• pp.85-91
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• 2013

The selective transport characteristics of $K^+$ and $Na^+$ of cell membrane model which irradiated by 60Co ${\gamma}$-ray was investigated. The cell membrane model used in this experiment was a Na+ type sulfonated copolymerized membrane of styrene and divinylbenezene. The initial flux of the ion was increased with increase of both $H^+$ ion concentration. In this experiment range(pH 0.5-3, temperature $15-65^{\circ}C$), first, the selectivity of $K^+$ and the ratio K+/Na+ of membrane which was not irradiated was about 1.06 - 1.13 and second, that of K+ and the ratio $K^+/Na^+$ of membrane which was irradiated was near about 0. And the driving force of pH of irradiated membrane was significantly increased about 4-5 times than membrane which was not irradiated. As selective transport of K+ and Na+ of cell membrane model were abnormal, cell damages were appeared at cell.

• Journal of the Korean Society of Propulsion Engineers
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• v.8 no.3
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• pp.17-26
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• 2004

In this paper, power transmission systems converts the shaft power of a Turbo-shaft Engine with Free Power Turbine into the generator power and be composed of a method being supplied in the thrust motor driving a propellers. Being used this, Gas turbine engine works to flat rating about 110 kw (147 shp) that the thrust motor be extremely supplied from the engine of 317shp. In this test equipment, the engine is installed with the flywheel being able to the damping function when happen to the varying load between gas turbine engine output-shaft and generator. Then if the flywheel of inertial moment be not considered, the generator and motor not get the required power from the engine for raising the load. Also it is certified that the engine works the abnormal operation. Hence the flywheel of inertial moment is determined the required range to do the performance analysis with the dynamic transient from the given and tested engine data. This system is able to get the required power after a mounting test with the redesigned flywheel.

• Journal of Powder Materials
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• v.27 no.2
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• pp.126-131
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• 2020

The grain growth behavior of M-type Sr hexaferrite (SrM) grains is investigated with the addition of MnCO₃. First, the SrM powder is synthesized by a conventional solid-state reaction. The powder compacts of SrM are sintered at 1250℃ for 2 h with various amounts of MnCO₃ (0, 0.5, 1.0, and 4.0 mol%). There is no secondary solid phase in any of the sintered samples. Relative density increases when MnCO₃ is added to the SrM. Obvious abnormal grain growth does not appear in any of the SrM samples with MnCO₃. The average grain size increases when 0.5 mol% MnCO₃ is added to the SrM. However, as the amount of MnCO₃ increase to over 0.5 mol%, the average grain size decreases. These observations allow us to conclude that the growth of SrM grains is governed by the two-dimensional nucleation grain growth mechanism, and the critical driving force for the growth of a grain decreases as the amount of MnCO₃ increases.

• Journal of Digital Contents Society
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• v.7 no.3
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• pp.153-160
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• 2006

It is not too much to say that invention of image divided the 19th and 20th century. Rapidly developed, produced and played images have a stronger effect on human beings and society. Today, images have an influence on forming interpersonal relationships by means of consciousness and ideas of new dimension, creating new image relationship different from verbal relationship between people. Especially moving image(image) is unlike other images, an image has unique psychological characteristics of its on. An image stimulates all the five human senses as well as sight, is easer to access and perceive than other media, and unable to control image development passively in general but get absorbed unconsciously very quickly. On 21th century As we are exposed to image whether consciously or unconsciously everyday, consideration on current times driving human beings and social relationship in an abnormal way is needed. Furthermore, new view of image study suggest to new relation of image that is a key factor to recover humanity and functions of society.