• 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.

• The Journal of the Acoustical Society of Korea
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• v.42 no.4
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• pp.320-328
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• 2023

Underwater active target detection is vital for defense systems, requiring accurate detection and estimation of distance and velocity. Sequential transmission is necessary at each beam angle, but divided pulse length leads to range ambiguity. Multi-frequency transmission results in time-bandwidth product losses when bandwidth is divided. To overcome these problem, we propose a novel method using Generalized Sinusoidal Frequency Modulation (GSFM) for rapid target detection, enabling low-correlation pulses between subpulses without bandwidth division. The proposed method allows for rapid updates of the distance and velocity of target by employing GSFM with minimized pulse length. To evaluate our method, we simulated an underwater environment with reverberation. In the simulation, a linear frequency modulation of 0.05 s caused an average distance estimation error of 50 % and a velocity estimation error of 103 % due to limited frequency band. In contrast, GSFM accurately and quickly tracked targets with distance and velocity estimation errors of 10 % and 14 %, respectively, even with pulses of the same length. Furthermore, GSFM provided approximate azimuth information by transmitting highly orthogonal subpulses for each azimuth.

• Korean Journal of Remote Sensing
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• v.39 no.5_4
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• pp.1075-1084
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• 2023

Satellite-derived data is collected by observing the Earth and is used in various fields such as national defense, natural disasters, location-based services, infrastructure, environment, energy, marine, and insurance. This study aims to present the virtuous cycle structure of the satellite information data industry and the business ecosystem model of the industry. As a research method, cases were collected and categorized from the following areas: literature, online, application, and content. The results show that the ecosystem model of the satellite information data industry provides an approach to content services in public and commercial areas, and develops various algorithmic technologies to facilitate content production and services at the level of complex general-purpose technologies. Second, in terms of content typology, satellite information data can be subdivided into monitoring content, urban space monitoring content, and satellite information content. Third, the consumption value of satellite content could be subdivided into informational value, environmental, social and governance (ESG) value, educational value, and content value. In order to expand the global content market, Korea will need to focus on creating an ecosystem for the satellite information industry and discovering differentiated content. It will also need to increase the popularization and accessibility of data to the general public and promote the Korean K-Satellite Information Data Industry ecosystem through government support, policy efforts, and policies such as establishing legal systems, increasing investment, and training human resources.

• The Korean Journal of Air & Space Law and Policy
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• v.31 no.2
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• pp.99-143
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• 2016

General aviation and air transport are two wings of the civil aviation industry. Chinese air transport is developing rapidly, and has become the world second air transport system only second to US since 2005. However, Chinese civil aviation is far behind the world average level, and cannot meet requirements of economic construction and social development. The transition and structural adjustment of Chinese economy provide the general aviation with a unprecedented broad market. The prospect of general aviation is promising and anticipated. The development of general aviation industry needs the legislative supports, and the current legislative conditions of Chinese general aviation are undoubtedly far behind the realistic requirements. Accelerating the legislation in Chinese general aviation industry requires scientific legislation concept. First, Legislation must promote development of general aviation industry. The general aviation will serves as a Chinese emerging industry that boosts domestic demand, promotes employment and expedite domestic economic development. We should, based on both the concept of promoting the industrial development of general aviation and national industrial planning, enact and rectify relative laws and regulations. And we should also straighten out the relationship between aviation security and industrial development and promote the revolution of low-altitude airspace management in an all-round way, in order to improve the utilization rate of airspace resources, classify and establish airspace, simplify examination and approval procedure and intensify operation management. In addition, what we should do is to expedite the infrastructure layout construction, guide the differentiated but coordinated development of general aviation industries in various areas, establish a united supervision mechanism of general aviation, redistrict the responsibilities of Chinese Air Control Agency and set up legislation, law enforcement and judicial systems with clarified institutions, clear positioning and classified responsibilities, so as to usher in a new era of the legislative management of Chinese general aviation industry. Second, shift the focus from regulations to both regulations and services. Considering the particularity of the general aviation, we should use American practices for reference and take into account both regulation and service functions when enacting general aviation laws. For example, we should reduce administrative licensing and market supervision, and adopt "criteria" and "approval" management systems for non-commercial and commercial aviation. Furthermore, pay attention to social benefits. Complete social rescuing mechanism through legislation. It should be clarified in legislation that general aviation operators should take the responsibilities of, and ensure to realize social benefits of environmental protection and ecological balance .Finally, rise in line with international standards. Modify Chinese regulations which is inconsistent with international ones to remove barriers to international cooperation. Specify basic legislative principles. One is the principle of coordination. Realize coordination between the civil aviation and general aviation, between military aviation and civil aviation, and among departments. Two is the principle of pertinence. The general aviation has its own rules and specialties, needing to be standardized using specialized laws and regulations. Three is the principle of efficiency. To realize time and space values of general aviation, we should complete rules in aerospace openness, general aviation airport construction, general aviation operations, and regulation enforcement. Four is the principle of security. Balance the maximum use of resources of Chinese airspace and the according potential threats to Chinese national interests and social security, and establish a complete insurance system which functions as security defense and indemnificatory measure. Establish a unified legal system. Currently, the system of Chinese general aviation laws consists of national legislation, administrative laws and regulations and civil aviation regulations (CAR). Some problems exist in three components of the system, including too general content, unclear guarantee measures, incomplete implementation details, and lacking corresponding pertinence and flexibility required by general aviation regulations, stringency of operation management and standards, and uniformity of standards. A law and regulation system, centered on laws and consisting of administrative laws regulations, industrial regulations, implementation details, industrial policies and local laws and regulations, should be established. It is suggested to modify the Civil Aviation Law to make general aviation laws complete, enact the Regulations of General Aviation Development, and accelerate the establishment, modification and abolition of Chinese general aviation laws to intensify the coordination and uniformity of regulations.

• Science of Emotion and Sensibility
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• v.21 no.4
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• pp.63-76
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• 2018

The purpose of this study was to investigate the effect of contact type textile electrode structure on heart activity signal acquisition for smart healthcare. In this study, we devised six contact type textile electrodes whose electrode size and configuration were manipulated for measuring heart activity signals using computerized embroidery. We detected heart activity signals using a modified lead II and by attaching each textile electrode to the chest band in four healthy male subjects in a standing static posture. We measured the signals four times repeatedly for all types of electrodes. The heart activity signals were sampled at 1 kHz using a BIOPAC ECG100, and the detected original signals were filtered through a band-pass filter. To compare the performance of heart activity signal acquisition among the different structures of the textile electrodes, we conducted a qualitative analysis using signal waveform and size as parameters. In addition, we performed a quantitative analysis by calculating signal power ratio (SPR) of the heart activity signals obtained through each electrode. We analyzed differences in the performance of heart activity signal acquisition of the six electrodes by performing difference and post-hoc tests using nonparametric statistic methods on the calculated SPR. The results showed a significant difference both in terms of qualitative and quantitative aspects of heart activity signals among the tested contact type textile electrodes. Regarding the configurations of the contact type textile electrodes, the three-dimensionally inflated electrode (3DIE) was found to obtain better quality signals than the flat electrode. However, regarding the electrode size, no significant difference was found in performance of heart signal acquisition for the three electrode sizes. These results suggest that the configuration method (flat/3DIE), which is one of the two requirements of a contact type textile electrode structure for heart activity signal acquisition, has a critical effect on the performance of heart activity signal acquisition for wearable healthcare. Based on the results of this study, we plan to develop a smart clothing technology that can monitor high-quality heart activity without time and space constraints by implementing a clothing platform integrated with the textile electrode and developing a performance improvement plan.

• The Korean Journal of Archival Studies
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• no.45
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• pp.219-253
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• 2015

The Records Management System in Japan has been developed to a comprehensive and unitary records management system based on the records life-cycle principle from the enactment of 'the Public Records and Archives Management Act' in 2009 and its implementation in April, 2011. The scope of objects has also been extended to documents of independent administrative institutions and specific confidential documents on diplomacy and defense. In addition, a series of Electronic Documents Management Systems have been built for the transfer of electronic records to the National Archives of Japan, which is called the Electronic Records Archives of Japan, in connection with the records and archives management systems covering creation, management, transfer, preservation, and use of electronic records. This paper deals with the core contents and characteristics of the records management system of Japan, focusing on the operational structure of the records and archives management law and electronic documents management. Firstly, The Cabinet Office and professional groups in records and archives management started to work on reformation of the records management system from 2003 and resulted in enactment of the Public Records and Archives Management Act in 2009. In that sense, the Public Records and Archives Management Act can be evaluated as a result of constant activities of the records management community in Japan for realization of accountabilities of government agencies to the general public. Secondly, the Public Records Management Act of Japan has a coherent multi-layer structure from the law, enforcement ordinances, guidelines, and to institutional documents management regulations in the operational system. This is a systematic structure for providing practical business units of each administrative agency with detailed standards on the basis of guidelines and making them to prepare their own specific application standards related to their unique businesses. Unlike the past, the National Archives of Japan became to be able to identify specific historial documents which should be transferred to the archives by selecting important historical records as early as possible after creating and receiving them in each institution through the retention schedule. Thirdly, Japan started to operate a system in regard to electronic records transfer and preservation in 2011. In order to prepare for it, each administrative agency has used EDMS in creation and management of electronic records. A Guideline for the Standard Format and Media released by the Cabinet Office in 2010 is also for the transfer of electronic records to the Electronic Records Archives of Japan. In future, it is necessary to conduct further studies on activities of the records and archives management community in Japan, relating to long-term preservation and use of electronic records.

• Journal of Internet Computing and Services
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• v.23 no.5
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• pp.145-154
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• 2022

Automatic Target Recognition (ATR) technology is emerging as a core technology of Future Combat Systems (FCS). Conventional ATR is performed based on IMINT (image information) collected from the SAR sensor, and various image-based deep learning models are used. However, with the development of IT and sensing technology, even though data/information related to ATR is expanding to HUMINT (human information) and SIGINT (signal information), ATR still contains image oriented IMINT data only is being used. In complex and diversified battlefield situations, it is difficult to guarantee high-level ATR accuracy and generalization performance with image data alone. Therefore, we propose a knowledge graph-based ATR method that can utilize image and text data simultaneously in this paper. The main idea of the knowledge graph and deep model-based ATR method is to convert the ATR image and text into graphs according to the characteristics of each data, align it to the knowledge graph, and connect the heterogeneous ATR data through the knowledge graph. In order to convert the ATR image into a graph, an object-tag graph consisting of object tags as nodes is generated from the image by using the pre-trained image object recognition model and the vocabulary of the knowledge graph. On the other hand, the ATR text uses the pre-trained language model, TF-IDF, co-occurrence word graph, and the vocabulary of knowledge graph to generate a word graph composed of nodes with key vocabulary for the ATR. The generated two types of graphs are connected to the knowledge graph using the entity alignment model for improvement of the ATR performance from images and texts. To prove the superiority of the proposed method, 227 documents from web documents and 61,714 RDF triples from dbpedia were collected, and comparison experiments were performed on precision, recall, and f1-score in a perspective of the entity alignment..

• The Korean Journal of Air & Space Law and Policy
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• v.20 no.1
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• pp.87-107
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• 2005

Land Remote Sensing' is defined as the science (and to some extent, art) of acquiring information about the Earth's surface without actually being in contact with it. Narrowly speaking, this is done by sensing and recording reflected or emitted energy and processing, analyzing, and applying that information. Remote sensing technology was initially developed with certain purposes in mind ie. military and environmental observation. However, after 1970s, as these high-technologies were taught to private industries, remote sensing began to be more commercialized. Recently, we are witnessing a 0.61-meter high-resolution satellite image on a free market. While privatization of land remote sensing has enabled one to use this information for disaster prevention, map creation, resource exploration and more, it can also create serious threat to a sensed nation's national security, if such high resolution images fall into a hostile group ie. terrorists. The United States, a leading nation for land remote sensing technology, has been preparing and developing legislative control measures against the remote sensing industry, and has successfully created various policies to do so. Through the National Oceanic and Atmospheric Administration's authority under the Land Remote Sensing Policy Act, the US can restrict sensing and recording of resolution of 0.5 meter or better, and prohibit distributing/circulating any images for the first 24 hours. In 1994, Presidential Decision Directive 23 ordered a 'Shutter Control' policy that details heightened level of restriction from sensing to commercializing such sensitive data. The Directive 23 was even more strengthened in 2003 when the Congress passed US Commercial Remote Sensing Policy. These policies allow Secretary of Defense and Secretary of State to set up guidelines in authorizing land remote sensing, and to limit sensing and distributing satellite images in the name of the national security - US government can use the civilian remote sensing systems when needed for the national security purpose. The fact that the world's leading aerospace technology country acknowledged the magnitude of land remote sensing in the context of national security, and it has made and is making much effort to create necessary legislative measures to control the powerful technology gives much suggestions to our divided Korean peninsula. We, too, must continue working on the Korea National Space Development Act and laws to develop the necessary policies to ensure not only the development of space industry, but also to ensure the national security.

• Journal of Food Hygiene and Safety
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• v.31 no.6
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• pp.399-405
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• 2016

The objective of this study was to determine the effect of sakso 2 corn kernels and cobs extracts on antioxidant activity in rats fed a high fat-cholesterol diet (HFC) for 2 weeks. 48 male Sprague-Dawley (4-weeks-old) were randomly divided into 6 groups: normal diet (N), HFC (C), HFC and 0.05% kernel extracts of Saekso 2 (T1), HFC and 0.25% kernel extracts of Saekso 2 (T2), HFC and 0.05% cob extracts of Saekso 2 (T3), HFC and 0.25% cob extracts of Saekso 2 (T4). The weight gain in all treatment groups were significantly lower and the food efficiency ratio (FER) in all treatment groups except T3 were lower than C group. Liver index (liver weight/100 g body weight) in N group and T2 were significantly lower than C group. The level of total cholesterol in plasma of N group and T2 were significantly lower than C group and HDL-cholesterol in plasma of N group and T2 were significantly lower than C group. Malondialdehyde (MDA) concentration of thiobarbituric acid reactive substances in N group, T3 and T4 were significantly lower than C group. Activity of catalase (CAT) in all treatment groups were lower than C group. These result suggest that saekso 2 corn kernels and cobs extracts may reduce oxidative damage through the activation of antioxidative defense systems in rats fed high fat-cholesterol diets.

• Korean Security Journal
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• no.62
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• pp.255-276
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• 2020

The mandatory police system, which plays a pivotal role in securing security and securing social safety as a security assistant, is expected to face difficulties in supplying the mandatory police manpower and securing absolute police manpower in the future according to the Ministry of Defense's abolition of the conversion service system. In this situation, this study intends to provide a concrete plan to replace the mandatory police officers as security assistants, recruiting contractors from civilians who are not military service resources or regular police officers, and using them for security assistance. More ultimately, this study goes beyond securing obligatory police to reduce or abolish mandatory police, which has been dealt with in previous studies. It aims to present the rescue and operation directions so that the police can provide quality public security services. In order to achieve the purpose of this study, this study 1) analyzes the current situation of police personnel, derives the necessity and justification of securing the police personnel or increasing the number of police personnel due to changes in security demand and security environment, and 2) After discussing the necessity and direction of reorganization, 3) deriving policy implications through analysis of foreign cases operating similar systems to derive specific plans for the introduction of security contractors for private contract workers in Korea. This study reviewed the specific operation plan and legal and institutional maintenance plan of private contract workers. In order to achieve these research objectives, this study 1) analyzes the current status of the police manpower and derives the necessity and justification of securing an absolute police manpower or increasing the manpower of the police in response to changes in security demand and security environment, and the current security aid system. 2) After discussing the necessity and orientation of reorganization of exinsting system of assistant police officer, 3) derive policy implications through analysis of foreign cases utilizing security aids similar to Korea, and 4) The specific operation plan and legal and institutional maintenance plan were presented. including security aids for private contract workers in Korea, from recruitment procedures to activities.