• Science of Emotion and Sensibility
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• v.27 no.1
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• pp.59-68
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• 2024

This study aimed to develop a soft fabric-based elbow-bending angle sensor that can replace conventional hard-type inertial sensors and a system for estimating bending angles using it. To enhance comfort during exercise, this study treated four fabrics (Bergamo, E-band, span cushion, and polyester) by single-walled carbon nanotube dip coating to create conductive textiles. Subsequently, one fabric was selected based on performance evaluations, and an elbow flexion angle sensor was fabricated. Gauge factor, hysteresis, and sensing range were employed as performance evaluation metrics. The data obtained using the fabricated sensor showed different trends in sensor values for the changes in the angle during bending and extending movements. Because of this divergence, the two movements were separated, and this constituted the one-step process. In the two-step process, multilayer perceptron (MLP) was employed to handle the complex nonlinear relationships and achieve high data accuracy. Based on the results of this study, we anticipate effective utilization in various smart wearable and healthcare domains. Consequently, a soft- fabric bending angle sensor was developed, and using MLP, nonlinear relationships can be addressed, enabling angle estimation. Based on the results of this study, we anticipate the effective utilization of the developed system in smart wearables and healthcare.

• Journal of the Institute of Convergence Signal Processing
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• v.25 no.2
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• pp.67-76
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• 2024

Various types of assistive devices have been developed for upper limb amputees over the years, with myoelectric prosthesis particularly aimed at improving user convenience by enabling a range of hand gestures beyond simple grasping, tailored to the size and shape of objects. In this study, we developed a five-finger myoelectric prosthesis mimicking human hand size and finger movements, utilizing motor and worm gear mechanisms for stable and independent operation. Based on this, we designed a control system for independent finger control through electromyographic signal input, proposed a state transition-based hand gesture conversion algorithm by selecting representative eight hand gestures and defining conversion condition parameters. We introduced training and usability evaluation methods, and conducted usability assessments among upper limb amputees using dedicated tools, confirming the potential for commercial application of the algorithm and observing adaptive capabilities and high performance through iterative evaluations.

• Journal of the Korean Institute of Landscape Architecture
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• v.52 no.4
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• pp.56-68
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• 2024

This study aimed to derive the concept and types of school outdoor spaces in Seoul. The research results showed that the concept of school outdoor space can be viewed as an outdoor activity space in schools that secures the value of integrated public life and communal life, including "behavioral rights, walking rights, living rights, urban rights, landscape rights (viewing rights), and nature experience rights." It can also be defined as a basic educational space that reflects the value of education, which is the basic function of schools and the characteristics of the community. As a result of the analysis based on the general types of outdoor spaces, it was found that the outdoor spaces of Seoul schools can be divided into three major categories: walking space (movement function), educational space (educational activities), and rest and other spaces (other services). Based on this, outdoor spaces were categorized and subcategorized to serve as the basis for policy implementation. These classifications are characterized by 1) simplifying the classification of spaces by function into three (movement functions, educational activities, and other services) to enable the use of outdoor spaces for integrated purposes; 2) reflecting the complex use of spaces by subdividing educational spaces focusing on major activities, and in particular, discovering complex spaces due to the three-dimensionalization of buildings; and 3) enabling spatial-level planning and facility element-level access according to school characteristics. It is characterized by applying the recent trends and systems of general outdoor space projects to the current situation of schools.

• The Korean Journal of Air & Space Law and Policy
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• v.27 no.1
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• pp.3-27
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• 2012

Although aviation safety and security have been improving, which has made air transportation more reliable, the international aviation community has witnessed a steady increase in the number of unruly passenger incidents. Under international law, the Tokyo Convention (The Convention on Offences and Certain Other Acts Committed on Board Aircraft of 1963) is applicable to unruly passenger issues. While the Tokyo Convention has been a successful convention which 185 member states have ratified, it has its shortcomings. Three major shortcomings are related to definition, jurisdiction, and enforcement. Firstly, the Tokyo Convention does not provide for a definition of unruly passengers, thereby resulting in a situation where conduct that may be considered to be a criminal offence in the country of embarkation may not be a criminal offence in the country where the aircraft lands. Having different definitions may lead to ineffective action on the part of air carriers. Secondly, the fact that the state of landing does not bear jurisdiction produces circumstances in which it is impossible to punish an unruly passenger who clearly committed an offence on board. Thirdly, the Tokyo Convention only recognizes the competence of the state of registry to exercise criminal jurisdiction but does not impose the duty to actually use that competence in any specific case. Along with ratifying the Tokyo Convention, Korea enacted the Aviation Navigation Safety Act in 1974 as a domestic legal approach to dealing with the problem of unruly passengers. Partially reflecting the ICAO's model legislation, Circular 288, the Aviation Safety and Security Act was enacted in 2002. Although the Korean Aviation Safety and Security Act is a comprehensive act which has been constantly updated, there is no provision with respect to jurisdiction and only the Korean criminal code is applicable to jurisdiction. The Korean criminal code establishes its jurisdiction in connection with territoriality, nationality and registration, which is essentially the same as the jurisdictional principles of the Tokyo Convention. Thus, the domestic legal regime cannot close the jurisdictional gap either. Similarly, Korean case law would not take an active posture to jurisdiction unless the offence in question is a serious one, such as hijacking. A Special Sub Committee of the ICAO Legal Committee (LCSC) was established to examine the feasibility of introducing amendments to the Convention on Offences and Certain Other Acts Committed on Board Aircraft of 1963 with particular reference to the issue of unruly passengers. The result of the ICAO's findings should lead to the modernization of the Tokyo Convention, thereby reducing the number of incidents caused by unruly passengers and enabling all parties concerned to respond to unruly passengers more effectively.

• Korean Security Journal
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• no.33
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• pp.197-228
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• 2012

The private security industry in Korea has rapidly proliferated. While the industry has grown quickly, though, private security officers have recently been implicated in incidents involving violence, demonstrating an urgent need for systematic reform and regulation of private security practices in Korea. Due to its quasi-public service character, the industry also risks losing the public's favor if it is not quickly disciplined and brought under legitimate government regulation: the industry needs professional standards for conduct and qualification for employment of security officers. This paper shares insights for the reform of the Korean private security industry through a study of the licensing and training requirements for private security businesses in the United States, mainly focusing on the Private Security Officer Employment Authorization Act (hereinafter the PSOEAA) and the California system. According to the PSOEAA, aspiring security officers shall submit to a criminal background check (a check of the applicants' criminal records). Applicants' criminal records should include not only felony convictions but also any other moral turpitude offenses (involving dishonesty, false statement, and information on pending cases). The PSOEAA also allows businesses to do background checks of their employees every twelve months, enabling the employers to make sure that their employees remain qualified for their security jobs during their employment. It also must be mentioned that the state of California, for effective management of its private security sector, has established a professional government authority, the Bureau of Security and Investigative Services, a tacit recognition that the private security industry needs to be thoroughly, professionally, and actively managed by a professional government authority. The American system provides a workable model for the Korean private security industry. First, this paper argues that the Korean private security industry should implement a more strict criminal background check system similar to that required by the PSOEAA. Second, it recommends that an independent professional government authority be established to oversee and enforce regulation of Korea's private security industry. Finally, this article suggests that education and training course be implemented to provide both diverse training as well as specialization and phasing.

• Journal of Korea Water Resources Association
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• v.48 no.7
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• pp.553-566
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• 2015

Acoustic Doppler Current Profilers(ADCPs) have capability to concurrently capitalize three-dimensional velocity vector and bathymetry with highly efficient and rapid manner, and thereby enabling ADCPs to document the hydrodynamic and morphologic data in very high spatial and temporal resolution better than other contemporary instruments. However, ADCPs are also limited in terms of the inevitable unmeasured regions near bottom, surface, and edges of a given cross-section. The velocity in those unmeasured regions are usually extrapolated or assumed for calculating flow discharge, which definitely affects the accuracy in the discharge assessment. This study aimed at scrutinizing a conventional extrapolation method(i.e., the 1/6 power law) for estimating the unmeasured regions to figure out the accuracy in ADCP discharge measurements. For the comparative analysis, we collected spatially dense velocity data using ADV as well as stationary ADCP in a real-scale straight river channel, and applied the 1/6 power law for testing its applicability in conjunction with the logarithmic law which is another representative velocity law. As results, the logarithmic law fitted better with actual velocity measurement than the 1/6 power law. In particular, the 1/6 power law showed a tendency to underestimate the velocity in the near surface region and overestimate in the near bottom region. This finding indicated that the 1/6 power law could be unsatisfactory to follow actual flow regime, thus that resulted discharge estimates in both unmeasured top and bottom region can give rise to discharge bias. Therefore, the logarithmic law should be considered as an alternative especially for the stationary ADCP discharge measurement. In addition, it was found that ADCP should be operated in at least more than 0.6 m of water depth in the left and right edges for better estimate edge discharges. In the future, similar comparative analysis might be required for the moving boat ADCP discharge measurement method, which has been more widely used in the field.

• Journal of Korea Water Resources Association
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• v.53 no.1
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• pp.15-27
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• 2020

Streamflow discharge as a fundamental riverine quantity plays a crucial role in water resources management, thereby requiring accurate in-situ measurement. Recent advances in instrumentations for the streamflow discharge measurement has complemented or substituted classical devices and methods. Among various potential methods, surface current meter using microwave has increasingly begun to be applied not only for flood but also normal flow discharge measurement, remotely and safely enabling practitioners to measure flow velocity postulating indirect contact. With minimized field preparedness, this method facilitated and eased flood discharge measurement in the difficult in-situ conditions such as extreme flood in active ways emitting 24.125 GHz microwave without relying on natural lights. In South Korea, a rectangular shaped instrument named with Microwave Water Surface Current Meter (MWSCM) has been developed and commercially released around 2010, in which domestic agencies charging on streamflow observation shed lights on this approach regarding it as a potential substitute. Considering this brand-new device highlighted for efficient flow measurement, however, there has been few noticeable efforts in systematic and comprehensive evaluation of its performance in various measurement and riverine conditions that lead to lack in imminent and widely spreading usages in practices. This study attempted to evaluate the MWSCM in terms of instrumen's monitoring configuration particularly regarding tilt and yaw angle. In the middle of pointing the measurement spot in a given cross-section, the observation campaign inevitably poses accuracy issues related with different tilt and yaw angles of the instrument, which can be a conventionally major source of errors for this type of instrument. Focusing on the perspective of instrument configuration, the instrument was tested in a controlled outdoor river channel located in KICT River Experiment Center with a fixed flow condition of around 1 m/s flow speed with steady flow supply, 6 m of channel width, and less than 1 m of shallow flow depth, where the detailed velocity measurements with SonTek micro-ADV was used for validation. As results, less than 15 degree in tilting angle generated much higher deviation, and higher yawing angle proportionally increased coefficient of variance. Yaw angles affected accuracy in terms of measurement area.

• Journal of the Korean earth science society
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• v.28 no.3
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• pp.311-323
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• 2007

The Yellow and East China seas received a vast amount of sediment $(>10^9ton/yr)$, which comes mainly from the Changjiang and Huanghe rivers of China and the Korean rivers. However, there are still no direct sedimentological-geochemical indicators, which can distinguish these two end-members (Korean and Chinese river sources) in these seas. The purpose of this study is to provide the potential geochemical-tracers enabling these river materials to be identified within the sediment load of the Yellow and East China seas. The compositions of major elements (Al, Fe, Mg, K, Ca, Na, and Ti) of Chinese and Korean river sediments were analyzed. To minimize the grain-size effect, furthermore, bulk sediments were separated into two groups, silt $(60-20{\mu}m)$ and clay $(<20{\mu}m)$ fractions, and samples of each fraction were analyzed for major and strontium isotope $(^{87}Sr/^{86}Sr)$ compositions. In this study, Fe/Al and Mg/Al ratios in bulk sediment samples, using a new Al-normalization procedure, are suggested as an excellent tool for distinguishing the source of sediments in the Yellow and East China seas. This result is clearly supported by the concentrations of these elements in silt and clay fraction samples. In silt fraction samples, Korean river sediments have much higher $^{87}Sr/^{86}Sr$ ratio $(0.7229{\sim}0.7253)$ than Chinese river sediments $(0.7169{\sim}0.7189)$, which suggests the distribution pattern of $^{87}Sr/^{86}Sr$ ratios as a new tracer to discriminate the provenance of shelf sediments in the Yellow and East China seas. On the basis of these geochemical tracers, clay fractions of southeastern Yellow Sea mud (SEYSM) patch may be a mixture of two sediments originated from Korea and China. In contrast, the geochemical compositions of silt fractions are very close to that of Korea river sediments, which indicates that the silty sediments of SEYSM are mainly originated from Korean rivers.

• Journal of Korean Society of Forest Science
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• v.50 no.1
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• pp.56-71
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• 1980

To study the changes of vegetational composition of each plant successional stage of Pinus densiflora forest caused by pine gall midge damage, Thecodiplosis japonensis, located in Kyonggi-do area, the middle part of Korea, four districts, Anseong, Yongin, Gwangju, and Gapyeong, were selected according to the length of insect damage duration. The forest in the Anseong district was the noninfested one selected as the check. And forests in Yongin, Gwangju, and Gapyeong were the recent]y damaged, severely damaged, and damage prolonged ones in sequence. It was considered that this order could be in concord with the gradual transition of plant successional stage. In view of temperature, precipitation and soil factors, these four districts were sited within the same environment. Four survey plots were selected from each district and the distance between them was 3~4 km. Then again four subplots were set within a plot. Through needle accumulation after insect infestation, light intensity, soil moisture content, and the amount of soil organic matter were increased and these conditions could create a favorable environment enabling the new species invasion and their growth. These were naturally closely related with the increase in quantity of Pinus densiflora defoliation. After considerable time lapse, the quantities of above mentioned factors decreased with the development of the new substitute tree species. It was found that Quercus mongolica was an excellently substitute tree species come first in this studied area. Species diversity increased to a degree at the early stage of the duration of pine gall midge damage and decreased thereafter. As the same manner, similarity index value between plots in the same district decreased to a degree and increased thereafter. This was linked admittedly with the increase and decrease of tree species and evenness. Synthesizing above mentioned results, the process of plant succession studied quantitatively by changes of relative density and relative importance value, it can be concluded that Pinus densiflora forest gives way to Genus Quercus forest in which Genus Lespedeza and Genus Rhododendron species become as subdominance species after removal of the Pinus densiflora trees damaged by pine gall midge.

• The Korean Journal of Nuclear Medicine Technology
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• v.19 no.2
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• pp.93-101
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• 2015

Purpose In SPECT image, scatter count is the cause of quantitative count error and image quality degradation. Thus, a wide range of scatter correction(SC) methods have been studied and this study is to evaluate the accuracy of CT based SC(CTSC) used in SPECT/CT as the comparison with existing energy window based SC(EWSC). Materials and Methods SPECT/CT images were obtained after filling air in order to acquire a reference image without the influence of scatter count inside the Triple line insert phantom setting hot rod(74.0 MBq) in the middle and each SPECT/CT image was obtained each separately after filling water instead of air in order to derive the influence of scatter count under the same conditions. In both conditions, Astonish(iterative : 4 subset : 16) reconstruction method and CT attenuation correction were commonly applied and three types of SC methods such as non-scatter correction(NSC), EWSC, CTSC were used in images filled with image. For EWSC, 9 sub-energy windows were set additionally in addition to main(=peak) energy window(140 keV, 20%) and then, images were acquired at the same time and five types of EWSC including DPW(dual photo-peak window)10%, DEW(dual energy window)20%, TEW(triple energy window)10%, TEW5.0%, TEW2.5% were used. Under the condition without fluctuations in primary count, total count was measured by drawing volume of interest (VOI) in the images of the two conditions and then, the ratio of scatter count of total counts was calculated as percent scatter fraction(%SF) and the count error with image filled with water was evaluated with percent normalized mean-square error(%NMSE) based on the image filled with air. Results Based on the image filled with air, %SF of images filled with water to which each SC method was applied is NSC 37.44, DPW 27.41, DEW 21.84, TEW10% 19.60, TEW5% 17.02, TEW2.5% 14.68, CTSC 5.57 and the most scattering counts were removed in CTSC and %NMSE is NSC 35.80, DPW 14.28, DEW 7.81, TEW10% 5.94, TEW5% 4.21, TEW2.5% 2.96, CTSC 0.35 and the error in CTSC was found to be the lowest. Conclusion In SPECT/CT images, the application of each scatter correction method used in the experiment could improve the quantitative count error caused by the influence of scatter count. In particular, CTSC showed the lowest %NMSE(=0.35) compared to existing EWSC methods, enabling relatively accurate scatter correction.