• Journal of the Korea institute for structural maintenance and inspection
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• v.15 no.6
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• pp.166-174
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• 2011

The object of this study is to evaluate the structural shear capacity of the PC girder-PC beam joint. The dapped end of PC beam and the ledger of PC girder are usually designed to design load. If the end of PC beam can be designed with continuous end, the dapped end of PC beam and the ledger of PC girder do not need to resist to all loads except dead load and construction load. The experimental program was carried out with 7 specimens containing the variable factors as the anchored method of the hanger bar, design load, be or not exist of ledger bars. As a result, the continuity of the dapped end and the ledger were ensured their safety although the design load was only the dead load and the construction load. The shear critical section was expanded toward the effective depth d, the distance from the supported position of the beam. If the ledger is designed according to PCI Design Handbook, the structural system of the ledger is as to the cantilever slab system. But the ledger of this study is as to the 3 side fixed slab system. Therefore the design of the ledger by PCI Design Handbook will lead to highly conservative results.

• Journal of Energy Engineering
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• v.23 no.2
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• pp.207-216
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• 2014

The energy loss can be divided into the loss caused by heat transfer and the loss caused by air flow. Heat transfer is the loss resulting from the heat transmittance of external wall, roof, and floor, and represents one of the most vulnerable elements of existing buildings. To prevent such loss, it is necessary to increase the mean heat transmittance of entire external wall, including the window, to a level above the standard regional value and ensure the air-tightness of window. The old buildings have the structure which is prone to the loss of greater air flow due to the air infiltration through the exit/entrance door upward along the stairway by the stack effect and simultaneous suction of air from each floor, and becomes even vulnerable to the loss of heat insulation for each floor, although the external wall and windows are the most vulnerable parts. The improvement plans for each floor need to be submitted in tandem with the diagnosis of whole building, regarding the diagnosis plan and energy improvement measures based on the survey of site, rather than adhering to the misconception that the replacement of window alone will result in energy-savings.

• Microbiology and Biotechnology Letters
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• v.43 no.4
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• pp.357-366
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• 2015

Quorum sensing (QS) is involved in the process of cell-to-cell communication and as a gene regulatory mechanism, which has been implicated in bacterial pathogenicity. Bacteria use this QS system to control a variety of physiological processes. In this study, pomegranate (Punica granatum L.) peel extract (PPE) was first screened for its ability to inhibit QS in bio-reporter strains (Chromobacterium violaceum and C. violaceum CV026). Next, the ability of PPE to inhibit swimming motility and biofilm formation was examined in Y. enterocolitica. Additionally, changes in the expression of specific genes involved in the synthesis of the N-acylhomoserine lactones (AHLs; yenI and yenR) and in the flagellar regulon (fliA, fleB and flhDC) were evaluated by reverse transcription (RT)-PCR. The results show that PPE specifically inhibited and reduced QS-controlled violacein production by 78.5% in C. violaceum CV026, and decreased QS-associated biofilm formation and swimming motility in Y. enterocolitica without significantly affecting bacterial growth. These inhibitory effects were also associated with the down-regulation of gene expression involved in the synthesis of AHLs and in motility. Our results suggest that PPE could be a potential therapeutic agent to prevent enteropathogens in humans, as well as highlight the need to further investigate the in vivo properties of PPE for clinical applications.

• The Journal of the Korea Contents Association
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• v.17 no.9
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• pp.449-465
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• 2017

Small and medium-sized company workers are ill-prepared for retirement due to low wages and poor working conditions, as result, are likely to get into poverty in retirement. The purpose of this study is to conduct a case study on the current status of financial and non-financial retirement preparation of the small and medium-sized company workers. The main findings are as follows. First, the small and medium-sized company workers show the anxiety about retirement. Many pre-retirees worry that their retirement savings may not generate enough income in retirement, and the level of benefits paid in public pension is inadequate. Second, they are preparing for retirement in the areas of finance, health, working after retirement and social activity. Third, they are realistic and practical in retirement decisions makings. they are considering household budget downsizing, cutting education costs, the low-waged job choice and cash flow preference in retirement. The safety and reality in preparation for retirement are top considerations. In conclusion, this case study shows that pre-retirees of small and medium-sized companies are seeking diverse retirement solutions. We need to design integrated and practical retirement planning programs to support their specific retirement needs.

• Journal of the Society of Disaster Information
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• v.10 no.2
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• pp.294-303
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• 2014

The state has the constitutional duty to secure the safety of its citizens and provide protection against any physical dangers. The Republic of Korea has a high threat of nuclear, biological and or chemical(hereafter referred to as NBC) attack from the Democratic People's Republic of Korea. Thus, the state has a responsibility to form a legislation to provide the protection for its citizens and implement duty to guarantee the human rights. Under the current legislation, the 'United Defense Act', 'Framework Act on Civil Defense' that are applied under wartime conditions are insufficient in providing the protection of the citizens of the state in the occurrence of NBC attack. Therefore, it is necessary that the 'Act for the Protection of Citizens in the occurrence of NBC Attack' is legislated to provide a system that protects the nation's citizens under the wartime conditions mentioned above. This paper incorporates a theoretical analysis of the need for the constitutional responsibility of the state to provide protection for its citizens under wartime conditions, the necessity of a specific measure to protect citizens during NBC attack, the relationship between 'Act for the Protection of Citizens in the occurrence of Nuclear, Chemical and or Biological Attack' and current legislations that are applied under wartime conditions, and the particulars of the proposed act.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.12
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• pp.1086-1092
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• 2012

It has been studied for DGPS/INS(Differential Global Positioning System/Inertial Navigation System) to offer the more precise and reliable navigation data with the aviation industry development. The flight performance evaluation of navigation system is very significant because the reliability of navigation data directly affect the safety of aircraft. Especially, the high-level navigation system, as DGPS/INS, need more precise flight performance evaluation method. The performance analysis is performed by comparing between the DGPS/INS navigation data and reference trajectory which is more precise than DGPS/INS. The GPS receiver, which is capable of post-processed CDGPS(Carrier-phase DGPS) method, can be used as reference system. Generally, the DGPS/INS is estimated the CG(Center of Gravity) point of aircraft while the reference system is output the position of GPS antenna which is mounted on the outside of aircraft. For this reason, estimated error between DGPS/INS and reference system will include the error due to lever arm. In order to more precise performance evaluation, it is needed to compensate the lever arm. This paper presents procedure and result of flight test which includes lever arm compensation in order to verify reliability and performance of DGPS/INS more precisely.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.14 no.3
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• pp.235-243
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• 2016

In the near future, many countries, including the Republic of Korea, will face a significant increase in low level radioactive waste (LLW) from nuclear power plant decommissioning. The purpose of this paper is to look at blending as a method for enhancing disposal options for low-level radioactive waste from the decommissioning of nuclear reactors. The 2007 U.S. Nuclear Regulatory Commission strategic assessment of the status of the U.S. LLW program identified the need to move to a risk-informed and performance-based regulatory approach for managing LLW. The strategic assessment identified blending waste of varying radionuclide concentrations as a potential means of enhancing options for LLW disposal. The NRC's position is that concentration averaging or blending can be performed in a way that does not diminish the overall safety of LLW disposal. The revised regulatory requirements for blending LLW are presented in the revised NRC Branch Technical Position for Concentration Averaging and Encapsulation (CA BTP 2015). The changes to the CA BTP that are the most significant for NPP operation, maintenance and decommissioning are reviewed in this paper and a potential application is identified for decommissioning waste in Korea. By far the largest volume of LLW from NPPs will come from decommissioning rather than operation. The large volumes in decommissioning present an opportunity for significant gains in disposal efficiency from blending and concentration averaging. The application of concentration averaging waste from a reactor bio-shield is also presented.

• Journal of radiological science and technology
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• v.28 no.3
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• pp.241-248
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• 2005

X-ray examinations represent the largest man-made source of radiation exposure for the population. The need for standardization of radiation exposures has been suggested and the guidance levels for various radiographic and radioisotope examinations has been proposed by the International Atomic Energy Aency(IAEA) as a safety standard. In many countries, the situation of medical radiographic exposures in each country should be researched before the appropriate guidance level is established. In this study, measurements of entrance surface dose, dose-area product(DAP), computed tomograghic dose index(CTDI) and mean glandular dose(MGD) were carried out in patients who underwent routine x-ray examinations, fluoroscopy, computed tomograghy and mamography in Korea. These measured quantities were compared with the results from the calculation method in previous study. And we suggested diagnostic reference levels in medical imaging in Korea.

• Journal of radiological science and technology
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• v.36 no.1
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• pp.11-17
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• 2013

Currently, there are many studies being conducted around the world to reduce exposure dose to radiation for patients to receive medical treatments in a safe environment. We developed and fabricated of this shield that the patients are protected from the radiation and are need of safety control during breast imaging. In this study, for breast imaging, GE Senography 2000D were used and set at SID 65cm, 28kVp, and 63mAs. The measuring instrument was Fluke's Victoreen 6000-529. And we performed Face Block on with 30 patients. The chamber on the actual thyroid glands to take CC and MLO and measure the dosage before and after wearing the Face Block. For the results, after wearing the Face Block, exposure was decreased by 53.8%-100% and 65.8% in average in CC View and by 50%-100% and 60.7% in average in MLO View. The development of the Face Block that practically decreased the exposure dose of thyroid glands, crystalline eyes during breast imaging and reduced the patients' anxiety during breast imaging. The Face Block is expected to improve patients' satisfaction and contribute to reducing patients' exposure dose, but more efforts should be made to reduce exposure dose to medical radiation.

• The Journal of Korean Physical Therapy
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• v.15 no.1
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• pp.82-95
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• 2003

Our health is intimately connected to the health of our environment. The contemporary world view which sees a radical distinction between humans as subjects and world as object can obscure our recognition of how much we rely on nature for health and survival. Indigenous traditions and contemporary scholars remind us that we live in a universe in which all things are connected, and in which nature continues to offer its gifts in co-creative partnership for the health and wellbeing of all. Living in awareness of our relationship with nature enables us to open more to the experience of nature's nurturing. Many complementary therapies derive from ancient practices that involve nature in healing partnership. Essential oils have been used for thousands of years. Hippocrates claimed that the way to health was through aromatic baths and massages. Much anecdotal evidence exists regarding aromatherapeutic positive effects on recipients. Aromatherapy is a branch of complementary or alternative therapy which is increasing in popularity, yet has scant scientific credibility. Aromatherapy should be defined as treatment using odors and practised as such. However, essential oils are usually used in conjunction with therapeutic massage and often combined with counselling of some kind. Aromatherapy complements and enhances the therapeutic powers of massage. Massage is one of the most wonderful ways to relax and is throughly beneficial to health. Massage can help unknot tense and aching muscles and other minor symptoms of stress, leaving patients fresh and energized. As the use of aromatherapy within a health care setting has grown so rapidly in recent years, and will continue to do so, the need for suitable training has become apparent. No health service can afford the risk of having staff who are inadequately trained in the practice of aromatherapy using essential oils incorrectly on those in a state of ill-health, especially if the essential oils used are not to a standard suitable for therapeutic use. Training to an acceptable level in aromatic therapy is essential for safety and effectiveness. Knowledge of the nature and make-up of essential oils, their effect on the body and the emotions, and how, when, and where to apply them is imperative in order for them to be beneficial to a patient's health. In order to achieve best practice, further research is necessary to explore the use of aromatherapy in the management of multiple disorder.