• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.2
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• pp.705-713
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• 2021

Because the cage assembly serves as the launch platform, an accurate aim is essential to ensure shooting accuracy for the target. On the other hand, the abnormal rotation of the cage due to the directional errors of the K-MLRS has continuously caused quality problems. The quality problem of weapon systems may have a negative impact on the military's power loss. In this study, improvement plans were derived by examining the defects and analyzing the directional errors of the K-MLRS launcher. In addition, all possible causes of directional errors were derived from the flow diagram for cage directionality. Based on the results, the defense design through the software program was intended to prevent the loss of direction. Through this study, the signal error of the resolver was improved by preventing unspecific signals in the data. Furthermore, the directional judgment method was improved to minimize the impact of data distortion. Lastly, directional storage and verification methods were improved so that data for the cage rotation direction would not be affected by errors. For the design improvement method, the reliability was verified through the system applicability. This study is expected to be a reference for failure analysis and design for similar weapon systems in the future.

• Analytical Science and Technology
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• v.35 no.5
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• pp.205-211
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• 2022

Deuterium (D) is an isotope with one more neutron number than hydrogen (H). Heavy elements rarely change their chemical properties with little effect even if the number of neutrons increases, but low-mass elements change their vibration energy, diffusion rate, and reaction rate because the effect cannot be ignored, which is called an isotope effect. Recently, in the semiconductor and display industries, there is a trend to replace hydrogen gas (H₂) with deuterium gas (D₂) in order to improve process stability and product quality by using the isotope effect. In addition, as the demand for D₂ in industries increases, domestic gas producers are making efforts to produce and supply D₂ on their own. In the case of high purity D₂, most of them are produced by electrolysis of heavy water (D₂O), and among D₂, hydrogen deuteride (HD) molecules are present as isotope impurities. Therefore, in order to maximize the isotope effect of hydrogen in the electronic industry, HD, which is an isotope impurity of D₂ used in the process, should be small amount. To this end, purity analysis of D₂ for industrial processing is essential. In this study, HD quantitative analysis of D₂ for high purity D₂ purity analysis was established and hydrogen isotope RM (Reference material) was developed. Since hydrogen isotopes are difficult to analyze with general gas analysis instrument, they were analyzed using a high-precision mass spectrometer (Gas/MS, Finnigan MAT271). High purity HD gas was injected into Gas/MS, sensitivity was determined by a signal according to pressure, and HD concentrations in two bottles of D₂ were quantified using the corresponding sensitivity. The amount fraction of HD in each D₂ was (4518 ± 275) μmol/mol, (2282 ± 144) μmol/mol. D₂, which quantifies HD amount using the developed quantitative analysis method, will be manufactured with hydrogen isotope RM and distributed for quality management and maintenance of electronic industries and gas producers in the future.

• The Journal of the Acoustical Society of Korea
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• v.42 no.4
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• pp.329-344
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• 2023

In this study, we comprehensively analyze the generalization performance of various deep learning-based active sonar target classifiers when applied to small and imbalanced active sonar datasets. To generate the active sonar datasets, we use data from two different oceanic experiments conducted at different times and ocean. Each sample in the active sonar datasets is a time-frequency domain image, which is extracted from audio signal of contact after the detection process. For the comprehensive analysis, we utilize 22 Convolutional Neural Networks (CNN) models. Two datasets are used as train/validation datasets and test datasets, alternatively. To calculate the variance in the output of the target classifiers, the train/validation/test datasets are repeated 10 times. Hyperparameters for training are optimized using Bayesian optimization. The results demonstrate that shallow CNN models show superior robustness and generalization performance compared to most of deep CNN models. The results from this paper can serve as a valuable reference for future research directions in deep learning-based active sonar target classification.

• Korean Journal of Culture and Social Issue
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• v.22 no.3
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• pp.387-410
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• 2016

This study conducted a review of the existential and psychological perspective about the risks and safe. The risk was identified as existential task through the existential philosophy and psychology discussed were the safety regulations as existential need. As existential anxiety that is caused by unmet and insufficiency of the existential needs and the existential task that was presented to identify the subjective risk. Subjective risk as existential anxiety, and suggested that serves as a compass to advance to the completion and the facing the existential. In addition, existential anxiety as a subjective function as a signal that can identify the problem conditions that expressed phenomena. Problematic aspect of a subjective risk was suggested that it can be adjusted through a method for supplying information that can be recognized by an experienced and symmetrical state with the direction of the expressed symptoms. The attempt to determine the existence of and psychological point of view, it gave provided the underlying psychological spokesman for the analysis of human society, including the Sewol ferry of Korea-type disaster. There are also presented some implications that can be applied effectively to give more psychological approach to future risk reduction and safety enhancement. In addition, this study through the various views presented by a comprehensive existential subject of several ways to adjust the status Theme conditioning method (Theme Condition Adjustment Theory: TCAT) to establish a theoretical basis for expecting it to be that.

• Korean Journal of Radiology
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• v.22 no.4
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• pp.624-633
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• 2021

Objective: To evaluate the reliability of CT measurements of muscle quantity and quality using variable CT parameters. Materials and Methods: A phantom, simulating the L2-4 vertebral levels, was used for this study. CT images were repeatedly acquired with modulation of tube voltage, tube current, slice thickness, and the image reconstruction algorithm. Reference standard muscle compartments were obtained from the reference maps of the phantom. Cross-sectional area based on the Hounsfield unit (HU) thresholds of muscle and its components, and the mean density of the reference standard muscle compartment, were used to measure the muscle quantity and quality using different CT protocols. Signal-to-noise ratios (SNRs) were calculated in the images acquired with different settings. Results: The skeletal muscle area (threshold, -29 to 150 HU) was constant, regardless of the protocol, occupying at least 91.7% of the reference standard muscle compartment. Conversely, normal attenuation muscle area (30-150 HU) was not constant in the different protocols, varying between 59.7% and 81.7% of the reference standard muscle compartment. The mean density was lower than the target density stated by the manufacturer (45 HU) in all cases (range, 39.0-44.9 HU). The SNR decreased with low tube voltage, low tube current, and in sections with thin slices, whereas it increased when the iterative reconstruction algorithm was used. Conclusion: Measurement of muscle quantity using HU threshold was reliable, regardless of the CT protocol used. Conversely, the measurement of muscle quality using the mean density and narrow HU thresholds were inconsistent and inaccurate across different CT protocols. Therefore, further studies are warranted in future to determine the optimal CT protocols for reliable measurements of muscle quality.

• Journal of the Korea Society of Computer and Information
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• v.29 no.4
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• pp.115-123
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• 2024

In this paper, we propose a vibration notification system that combines navigation information and wearable bands to ensure safe driving for the transportation vulnerable. This system transmits navigation driving information to a linked application, converts it into a vibration signal, and provides notifications through a wearable band. Existing navigation systems focus on providing route guidance and location information, so the driver's concentration is dispersed, and safety and convenience are deteriorated, especially for those with mobility impairments, due to standard vision and delayed recognition of stimuli, resulting in an increasingly high traffic accident rate. To solve this problem, navigation driving information is converted into vibration signals through a linked application, and vibration notifications for events, left turns, right turns, and speeding are provided through a wearable band to ensure driver safety and convenience. In the future, we will use cameras and vehicle sensors to increase awareness of safety inside and outside the vehicle by adding a function that provides notifications with vibration and LED when the vehicle approaches or recognizes an object, and we will continue to conduct research to build a safer driving environment. plan.

• Environmental and Resource Economics Review
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• v.33 no.2
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• pp.113-133
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• 2024

Variable renewable energy (VRE) such as solar and wind power is the main sources of achieving carbon net zero, but it undermines the stability of power supply due to high variability and uncertainty. Energy storage system (ESS) can not only reduce the curtailment of VRE by load shifting but also contribute to stable power system operation by providing ancillary services. This study analyzes how the allocation of ESS resources between load shifting and ancillary service can contribute to maximizing the efficiency of power supply in a situation where the problems caused by VRE are becoming more and more serious. A stochastic power system optimization model that can realistically simulate the variability and uncertainty of VRE was applied. The analysis time point was set to 2023 and 2036, and the optimal resource allocation strategy and benefits of ESS by varying VRE penetration levels were analyzed. The analysis results can be largely summarized into the following three. First, ESS provides excellent functions for both load shifting and ancillary service, and it was confirmed that the higher the reserve price, the more limited the load shifting and focused on providing reserve. Second, the curtailment of VRE can be a effective substitute for the required reserve, and the higher the reserve price level, the higher the curtailment of VRE and the lower the required amount of reserve. Third, if a reasonable reserve offer price reflecting the opportunity cost is applied, ESS can secure economic feasibility in the near future, and the higher the proportion of VRE, the greater the economic feasibility of ESS. This study suggests that cost-effective low-carbon transition in the power system is possible when the price signal is correctly designed so that power supply resources can be efficiently utilized.

• Cartoon and Animation Studies
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• s.42
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• pp.293-313
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• 2016

The target stimulating human's sensitivity can include several things; the first is human like us including beautiful women and cute babies. The next ranking is the dog animal that established itself as a human's companion. It is the 3B law(beauty, baby, beast - much used in the ad or election due to the positive image) that is widely used in the advertising. This relationship is being expressed in the art history for a long time. Dogs that have lived a history more than 10 thousand years with humans hunted, protected flock of sheep, and kept the farmer's house and property. They have been human's assistants and companion who entered into the modern urban culture. Like this, dogs have adapted to several situations endlessly such as the nomadic life, farming, country life, and urban life. This paper will explore the close relationship of humans and companion animals through various icons of dogs and pups that appeared through a number of artists' skills. The companion animal means an animal that lives with people, which means the relationship of round-trip rather than the one-way relation those each other gives a help. Therefore, there artist tries to examine the figure of great hunter for survival, highly evaluated figure as the royal dignity, and the mascot-like figure delivering the daily happiness to modern people as presenting joy through a discussion of the 'countenance', a visual signal of the dogs and pups. They have been influenced by screen and popular media in 20C. Snoopy, a main character of and the movie <101 Dalmatians> made a success on the theater and television when Beagle and Dalmatian were prevalent. These main characters make audience feel happy involuntarily. Like this, the continuous and old friendship of the human and dogs will be confirmed again through the icon of dogs and pups consisting of the communication of artists and readers in the modern shape art, and it is hoped to be a psychological stabilizing effect to modern people living in the intense modern society. Therefore, it is expected this study paper will be reborn as a new text and be expanded as an effective communication in the journey of dogs and human in the future in investigating the communion of dogs and human.

• Science of Emotion and Sensibility
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• v.13 no.1
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• pp.187-196
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• 2010

Recently, people have been suffering from stress-related fatigue and psychological disorders. Most people depend on medicine for pain relief; many treat pain also through alternative medicine or replacement therapy. However, drug therapy has many side effects, including increased stress after the therapy. In comparison, alternative therapies such as massage and foot reflexology are less damaging to the body, and such therapies can be provided without physical or psychological discomfort. In this regard, the author had previously co-developed color foot reflexology, which combines the merits of color therapy and foot reflexology; color foot reflexology has been shown to have beneficial effects without undue pain. This study investigates the effects of color foot reflexology on the physiological response of the body by comparing the body’s response to the signal with that to the placebo. Healthy adult subjects were selected for the experiment, which was conducted under optimal experimental conditions and design. The results indicated that when stimulated, parasympathetic nerves increased in HRV and that blood pressure, pulse, body heat, peripheral blood flow were dramatically activated. However, the results for the placebo indicated minimal changes or irregular outcomes. The results provide strong evidence for the beneficial effects of the color foot reflexology instrument on the autonomic nervous system and on the physiological response of the body. Future research is warranted to verify the results of the current study by examining patients suffering from diseases and disorders arising from irregular physiological functions in the context of the foot.

• Korean Journal of Remote Sensing
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• v.36 no.2_2
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• pp.249-261
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• 2020

Coastal monitoring using multiple platforms/sensors is a very important tools for accurately understanding the changes in offshore marine environment and disaster with high temporal and spatial resolutions. However, integrated observation studies using multiple platforms and sensors are insufficient, and none of them have been evaluated for efficiency and limitation of convergence. In this study, we aimed to suggest an integrated observation method with multi-remote sensing platform and sensors, and to diagnose the utility and limitation. Integrated in situ surveys were conducted using Rhodamine WT fluorescent dye to simulate various marine disasters. In September 2019, the distribution and movement of RWT dye patches were detected using satellite (Kompsat-2/3/3A, Landsat-8 OLI, Sentinel-3 OLCI and GOCI), unmanned aircraft (Mavic 2 pro and Inspire 2), and manned aircraft platforms after injecting fluorescent dye into the waters of the South Sea-Yeosu Sea. The initial patch size of the RWT dye was 2,600 ㎡ and spread to 62,000 ㎡ about 138 minutes later. The RWT patches gradually moved southwestward from the point where they were first released,similar to the pattern of tidal current flowing southwest as the tides gradually decreased. Unmanned Aerial Vehicles (UAVs) image showed highest resolution in terms of spatial and time resolution, but the coverage area was the narrowest. In the case of satellite images, the coverage area was wide, but there were some limitations compared to other platforms in terms of operability due to the long cycle of revisiting. For Sentinel-3 OLCI and GOCI, the spectral resolution and signal-to-noise ratio (SNR) were the highest, but small fluorescent dye detection was limited in terms of spatial resolution. In the case of hyperspectral sensor mounted on manned aircraft, the spectral resolution was the highest, but this was also somewhat limited in terms of operability. From this simulation approach, multi-platform integrated observation was able to confirm that time,space and spectral resolution could be significantly improved. In the future, if this study results are linked to coastal numerical models, it will be possible to predict the transport and diffusion of contaminants, and it is expected that it can contribute to improving model accuracy by using them as input and verification data of the numerical models.