• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.5A
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• pp.557-564
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• 2009

In recent years, there have been numerous explosion-related accidents due to military and terrorist activities. Such incidents caused not only damages to structures but also human casualties, especially in urban areas. To protect structures and save human lives against explosion accidents, better understanding of the explosion effect on structures is needed. In an explosion, the blast overpressure is applied to concrete structures as an impulsive load of extremely short duration with very high pressure and heat. Generally, concrete is known to have a relatively high blast resistance compared to other construction materials. However, information and test results related to the blast experiment of internal and external have been limited due to military and national security reasons. Therefore, in this paper, to evaluate blast effect on reinforced have concrete structure and its protective performance, blast tests are carried out with $1.0m{\times}1.0m{\times}150mm$ reinforce concrete slab structure at the Agency for Defence Development. The standoff blast distance is 1.5 m and the preliminary tests consists with TNT 9 lbs and TNT 35 lbs and the main tests used ANFO 35 lbs. It is the first ever blast experiment for nonmilitary purposes domestically. In this paper, based on the basic experiment procedure and measurement details for acquiring structural behavior data, the blast experimental measurement system and procedure are established details. The procedure of blast experiments are based on the established measurement system which consists of sensor, signal conditioner, DAQ system, software. It can be used as basic research references for related research areas, which include protective design and effective behavior measurements of structure under blast loading.

• Journal of Korea Entertainment Industry Association
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• v.13 no.7
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• pp.375-384
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• 2019

The purpose of this study was to investigate the effects of long-term aerobic dancing exercise on body composition, physical fitness and mental function in older women over 70 years old. All subjects were limited to older women aged 70 to under 85. The experimental group performed aerobic exercise of 2-3 times a week for 9.2 ± 4.6 yrs, and the control group did not perform any regular exercise and spent 3-4 times a week mainly in the relaxing facility for older. As a results in this study, the weight, muscle mass and body fat percentage of the aerobic group were not significantly different from those of the control group, but there were significantly positive effects of aerobic group in visceral fat mass, abdominal obesity rate(%), body water content and systolic blood pressure(p < .05). In terms of physical fitness, Sit & reach, one-legged stand (right) and TUG of the aerobic group were significantly higher than those of the control group(p < .05), but there were no significant differences between two groups in the shoulder flexibilities and grip strength. MMSE as a cognitive function was not significantly different between the two groups, but GDS was significantly lower in the aerobic group than in the control group(p < .05). According to the correlation analysis between all variables and MMSE and GDS, MMSE was significantly inversely correlated with height (r = -0.425)(p < .05), and no correlation was detected with other variables. However, GDS have signitively negative correlations with resting heart rate(r = -0.464), sit & reach(r = -0.525) left(r = -0.491) and right grip strengths(r = -0.635) as well as positive correlation systolic blood pressure(r = 0.482) and TUG (r = 0.479), respectively(p < .05). In conclusion, long-term aerobic exercise of elderly women over 70 older had positive effects on variables related to metabolic disease (visceral fat and resting heart rate), silver fitness variables related to falls, and depression level in the elderly.

• Korean Journal of Social Welfare Studies
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• v.41 no.4
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• pp.189-224
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• 2010

Nowadays Korean society has a fast growing population of North Korean immigrant youth. Especially, North Korean immigrant youth, who are discontinuing formal education, experience difficulties in social exclusion and adaptation. Therefore, the purpose of this study was to understand the experiences of adaptation and social support of North Korean immigrant youth discontinuing formal education, and to seek affirmative supporting plans and solutions for their adaptation. The methodology utilized for this study was a case study research. On the basis of the results and categorization, 'a network between overall categories and of early adaptation' was derived. The major findings of this study are summarized as follows. First, the participants of this study experienced major difficulties during 'economical adaptation', and their economical adaptation was strongly interrelated with their 'educational adaptation'. The discontinuing of their education resulting from their fleeing period caused 'academic differential and age disparity.' Thus they could not enroll in the formal education system, and their insufficient educational background resulted in low wages and overwork due to manual labor jobs. Second, participants recognized 'interpersonal relations' as the most essential factor in adaptation, and 'social support' from the interpersonal relations played an important role in adaptation to and comfort in Korean society. 'Interactions with South Koreans' was recognized as a significant resource for gaining informational and appraisal support, but was not activated satisfactorily. On the other hand, interaction with North Korean immigrants was avoided by the reason that 'there's nothing to learn', however emotional support from North Korean immigrants of close relationship played an important role in participants' adaptation, especially in all aspects of psychological adaptation. Third, participants experienced a lot of difficulties and stresses in their 'physical health and psychological adaptation'. Their chronic diseases worsened by remaining untreated, and female perceived symptoms were observed more often than in male. Meanwhile, excessive 'stresses' from the unfamiliar environment of South Korea negatively affected their psychological adaptation. However, they were satisfied with sense of liberty and security from living in a democratic society.

• Korean Journal of Social Welfare Studies
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• v.42 no.1
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• pp.333-370
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• 2011

This study views the aged inequalities according to the inequality hypothesis of the life course perspective in OECD 10 countries. Focusing on educational level which is early social status and welfare state regime which is social structure factors of inequality, this study analyzes income inequality for the aged who have transformed into old age period from non-aged period. The analysis is based on the data SHARE of Europe and HRS of USA. The main results of this study are summarized in four points. First, the income inequality is quite high by welfare system and the educational level. Second, the income inequality is somewhat reduced in case the people move from the period of non-aged to the period of aged. However, gini coefficient is still high(0.475). Considering welfare state regimes, although the income inequality is high in conservative regime of non-aged period, this would be higher in aged period. This result supports cumulative advantages/disadvantages hypothesis. The liberal regime remains high income inequality which supports the theoretical argument of status maintenance. Social democratic regime provides evidence to offer some support for the status leveling hypothesis. In there, income inequality is lower in aged period even though income inequality of non-aged period is low. Third, the cumulative advantages/disadvantages of disposable income according to educational level are strengthened and heterogeneity is grown in case people transition from the late period of non-aged to aged period. But public pension has been more equally distributed than gross income. Fourth, seeing welfare state regimes, public pension of aged-period is more inequally distributed than that of non-aged period in liberal and conservative regime. Specially in conservative regime, inequality of gross income is very high and public pension is also inequally distribute So this might show that the social security system strengthens the cumulative advantages/disadvantages. However, in the social democratic regime, public pension is more equally distributed than gross income and it could be much more equally distributed in aged period, which can support the status leveling hypothesis.

• Land and Housing Review
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• v.14 no.4
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• pp.1-16
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• 2023

As population ageing and shrinking accompanied by dramatically expanded individual life expectancy and declining fertility rate is a global phenomenon, ageing becomes its broader perspective of ageing well embedded into sustained health and well-being, and also the fourth industrial revolution speeds up a more robust and inclusive view of smart ageing. While the latest paradigm of SA has gained considerable attention in the midst of sharply surging demand for health and social services and rapidly declining labor force, the definition has been widely and constantly discussed. This research is to constitute a conceptual framework of smart ageing (SA) from systematic literature review and the use of a series of secondary data and Geographical Information Systems(GIS), and to explore its components. The findings indicate that SA is considered to be an innovative approach to ensuring quality of life and protecting dignity, and identifies its constituents. Indeed, the construct of SA elaborates the multidimensional nature of independent living, encompassing three spheres - Aging in Place (AP), Well Aging (WA), and Active Ageing (AA). AP aims at maintaining independence and autonomy, entails safety, comfort, familiarity and emotional attachment, and it values social supports and services. WA assures physical, psycho-social and economic domains of well-being, and it concerns subjective happiness. AA focuses on both social engagement and economic participation. Moreover, the three constructs of SA are underpinned by specific elements (right to housing, income adequacy, health security, social care, and civic engagement) which are interrelated and interconnected.

• Journal of Public Diplomacy
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• v.2 no.2
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• pp.27-52
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• 2022

Objectives: The neighboring countries of South Korea and Japan in Northeast Asia have interacted in both positive and negative ways, at times as close partners and other times adversaries, throughout their long and thorny history of extensive dynamics. The controversial dispute over Dokdo is one of the most critical issues evoking harsh tensions and arguments asserting wholly opposite claims. Dokdo is a small island between two coastal states, but significant in terms of territorial, botanical, and marine resources, and thus ownership of the island has become a point of conflict accompanied by a troubled history. But why has Dokdo been a source of conflicts and how should the controversial Dokdo issue be addressed in a way that fosters positive influence and co-prosperity? Methods: This study provides comprehensive and critical insights from a wealth of previous research and strategic suggestions for the Korean government. It utilizes the three perspectives of historical documents and political context, international regulations and legal frames, and public diplomacy. Furthermore, it applies these resources to negotiation theories and strategies to propose reasonable solutions. Results: This study suggests that it is important for Korea and Japan to try to build mutual trust through more active communication and interaction in order to understand each other before attempting to create a formal resolution via negotiation. In addition to these efforts, Korea needs to be ready for the inevitable need to take decisive action in terms of negotiation, using analytic and efficient strategies. The study proposes three solutions: 1) Strong Action Strategy, 2) International Legal Strategy, and 3) Public Diplomacy Strategy. Conclusions: From the perspective of public diplomacy, the Dokdo issue needs to be converted from a symbol of conflicts between Korea and Japan into a symbol of peace and co-prosperity. In addition to promoting a positive relationship between the two states, it can also contribute to the security environment of the Northeast Asian region and global peace.

• Korean Journal of Ichthyology
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• v.35 no.4
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• pp.224-235
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• 2023

South Korea is the only divided nation globally, marked by a military demarcation line establishing demilitarized and civilian control zones, ensuring national security. Consequently, these areas exhibit relatively minimal ecological disruption compared to other regions. However, the threat to safety persists due to the presence of unexploded ordnances and landmines, imposing significant constraints on ecological research. To address this, we conducted a comparative study utilizing eDNA analysis as a supplementary and alternative approach within three points of the "Road of Peace" - Inje, Yanggu, and Hwacheon courses, located within the civilian control zone. Direct surveys and indirect eDNA sampling were carried out in May, July, and September of 2022. Genetic material obtained from the samples underwent amplification, library preparation, MiSeq sequencing, and subsequent ASV generation for indirect analysis. These results were then compared with the findings of direct surveys. Our findings revealed the detection of eDNA for both observed species at the Yanggu-1 point, and for two out of four species at Yanggu-2. Hwacheon-1 displayed the detection of eDNA for one out of one observed species, whereas Hwacheon-2 yielded seven out of twelve, Hwacheon-3 showed four out of six, and all one observed species at Hwacheon-4 exhibited eDNA detection. Consequently, approximately 69% of the fish species identified through direct surveys were confirmed by indirect eDNA analysis. It is necessary to verify if certain fish species, such as the continental trout and catfish, have genetic information registered in the NCBI database. Additionally, it is believed that further marker development research utilizing different genetic sequences is essential. Given the limitations imposed by the hazardous nature of the surveyed civilian control zone, eDNA analysis proves to be a suitable supplement for fish research in the area.

• Korean Journal of Remote Sensing
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• v.40 no.3
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• pp.295-305
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• 2024

This study aims to analyze the micro-sedimentary structures of the Hwangdo tidal flats using ultra-high resolution unmanned aerial vehicle (UAV) data. Tidal flats, located in the transitional area between land and sea, constantly change due to tidal activities and provide a unique environment important for understanding sedimentary processes and environmental conditions. Traditional field observation methods are limited in spatial and temporal coverage, and existing satellite imagery does not provide sufficient resolution to study micro-sedimentary structures. To overcome these limitations, high-resolution images of the Hwangdo tidal flats in Chungcheongnam-do were acquired using UAVs. This area has experienced significant changes in its sedimentary environment due to coastal development projects such as sea wall construction. From May 17 to 18, 2022, sediment samples were collected from 91 points during field surveys and 25 in-situ points were intensively analyzed. UAV data with a spatial resolution of approximately 0.9 mm allowed identifying and extracting parameters related to micro-sedimentary structures. For mud cracks, the length of the major axis of the polygons was extracted, and the wavelength and ripple symmetry index were extracted for ripple marks. The results of the study showed that in areas with mud content above 80%, mud cracks formed at an average major axis length of 37.3 cm. In regions with sand content above 60%, ripples with an average wavelength of 8 cm and a ripple symmetry index of 2.0 were formed. This study demonstrated that micro-sedimentary structures of tidal flats can be effectively analyzed using ultra-high resolution UAV data without field surveys. This highlights the potential of UAV technology as an important tool in environmental monitoring and coastal management and shows its usefulness in the study of sedimentary structures. In addition, the results of this study are expected to serve as baseline data for more accurate sedimentary facies classification.

• The Korean Society of Law and Medicine
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• v.24 no.4
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• pp.103-128
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• 2023

According to the current act of Decision-Marking in Life-Sustaining Medicine, the decision to withhold or discontinue life-sustaining treatment is primarily based on the wishes of a patient in the dying process. Decision-making regarding life-sustaining treatment for these patients is made by the patient, if he or she is conscious, directly expressing his/her intention for life-sustaining treatment in writing or verbally or by writing an advance medical directive and physician orders for life-sustaining treatment. It can be exercised. On the other hand, if the patient has not written an advance medical directive or physician orders for life-sustaining treatment, the patient's intention can be confirmed with a statement from the patient's family, or a decision to discontinue life-sustaining treatment can be made with the consent of all members of the patient's family. However, in the case of an unrelated patient who has no family or whose family is unknown, if an advance medical directive or physician orders for life-sustaining treatment are not written before hospitalization and a medical condition prevents the patient from expressing his or her opinion, the patient's will cannot be known and the patient cannot be informed. A situation arises where a decision must be made as to whether to continue or discontinue life-sustaining treatment. This study reviewed discussions and measures for unbefriended patients under the current law in order to suggest policy measures for deciding on life-sustaining treatment in the case of unbefriended patients. First, we looked at the application of the adult guardian system, but although an adult guardian can replace consent for medical treatment that infringes on the body, permission from the family court is required in cases where death may occur as a direct result of medical treatment. It cannot be said to be an appropriate solution for patients in the process of dying. Second, in accordance with Article 14 of the Life-Sustaining Treatment Decision Act, we looked at the deliberation of medical institution ethics committees on decisions to discontinue life-sustaining treatment for patients without family ties.Under the current law, the medical institution ethics committee cannot make decisions on discontinuation of life-sustaining treatment for unbefriended patients, so through revision, matters regarding decisions on discontinuation of life-sustaining treatment for unbefriended patients are reflected in Article 14 of the same Act or separate provisions for unbefriended patients are made. It is necessary to establish and amend new provisions. In addition, the medical institution ethics committee must make a decision on unbefriended patients, but if the medical institution cannot make such a decision, there is a need to revise the law so that the public ethics committee can make decisions, such as discontinuing life-sustaining treatment for unbefriended patients.

• Maritime Security
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• v.7 no.1
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• pp.31-60
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• 2023

This study proposes a new convergence weapon system that combines the covert placement and detection abilities of a self-propelled mobile mine with the rapid tracking and attack abilities of supercavitating rocket torpedoes. This innovative system has been designed to counter North Korea's new underwater weapon, 'Haeil'. The concept behind this convergence weapon system is to maximize the strengths and minimize the weaknesses of each weapon type. Self-propelled mobile mines, typically placed discreetly on the seabed or in the water, are designed to explode when a vessel or submarine passes near them. They are generally used to defend or control specific areas, like traditional sea mines, and can effectively limit enemy movement and guide them in a desired direction. The advantage that self-propelled mines have over traditional sea mines is their ability to move independently, ensuring the survivability of the platform responsible for placing the sea mines. This allows the mines to be discreetly placed even deeper into enemy lines, significantly reducing the time and cost of mine placement while ensuring the safety of the deployed platforms. However, to cause substantial damage to a target, the mine needs to detonate when the target is very close - typically within a few yards. This makes the timing of the explosion crucial. On the other hand, supercavitating rocket torpedoes are capable of traveling at groundbreaking speeds, many times faster than conventional torpedoes. This rapid movement leaves little room for the target to evade, a significant advantage. However, this comes with notable drawbacks - short range, high noise levels, and guidance issues. The high noise levels and short range is a serious disadvantage that can expose the platform that launched the torpedo. This research proposes the use of a convergence weapon system that leverages the strengths of both weapons while compensating for their weaknesses. This strategy can overcome the limitations of traditional underwater kill-chains, offering swift and precise responses. By adapting the weapon acquisition criteria from the Defense force development Service Order, the effectiveness of the proposed system was independently analyzed and proven in terms of underwater defense sustainability, survivability, and cost-efficiency. Furthermore, the utility of this system was demonstrated through simulated scenarios, revealing its potential to play a critical role in future underwater kill-chain scenarios. However, realizing this system presents significant technical challenges and requires further research.