• The Journal of the Korea Contents Association
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• v.21 no.8
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• pp.478-488
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• 2021

This study analyzes the change in the contribution of the elderly to income inequality by using the Gini coefficient and the decile distribution ratio from the data of the Korea Welfare Panel Survey from 2007 to 2018 on economic inequality in old age. According to the study, the Gini coefficient of total income gradually decreased from 0.430 in 2007 to 0.383 in 2018. As a result, inequality decreased. Also, the higher the income quintile, the higher the income growth rate. Market income inequality has increased and inequality between public and private transfer income has decreased. Analysis of the contribution of income inequality to total income confirmed that public transfer income has replaced the role of private transfer income in reducing inequality over time. The expansion of public transfer income for the maintenance of basic living of the elderly is an important source of income for the elderly despite the crowding-out effect of private transfer income, market income, public and private transfer income, which are components of the income structure of the elderly, mutually complement total income. Therefore, it is important to identify income sources that contribute to alleviating income inequality among the elderly and reflect them in policy-making process.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.43 no.2 s.308
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• pp.19-29
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• 2006

As the security of personal information is becoming more important in mobile phones, we are starting to apply iris recognition technology to these devices. In conventional iris recognition, magnified iris images are required. For that, it has been necessary to use large magnified zoom & focus lens camera to capture images, but due to the requirement about low size and cost of mobile phones, the zoom & focus lens are difficult to be used. However, with rapid developments and multimedia convergence trends in mobile phones, more and more companies have built mega-pixel cameras into their mobile phones. These devices make it possible to capture a magnified iris image without zoom & focus lens. Although facial images are captured far away from the user using a mega-pixel camera, the captured iris region possesses sufficient pixel information for iris recognition. However, in this case, the eye region should be detected for accurate iris recognition in facial images. So, we propose a new fast iris detection method, which is appropriate for mobile phones based on corneal specular reflection. To detect specular reflection robustly, we propose the theoretical background of estimating the size and brightness of specular reflection based on eye, camera and illuminator models. In addition, we use the successive On/Off scheme of the illuminator to detect the optical/motion blurring and sunlight effect on input image. Experimental results show that total processing time(detecting iris region) is on average 65ms on a Samsung SCH-S2300 (with 150MHz ARM 9 CPU) mobile phone. The rate of correct iris detection is 99% (about indoor images) and 98.5% (about outdoor images).

• Journal of the Korean Geosynthetics Society
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• v.10 no.2
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• pp.73-79
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• 2011

Based on the results of Part 1 of our two-parts paper, the possibility on field applicability of CMDS(Coal Mine Drainage Sludge) mixed with bentonite and cement as a liner in landfill sites was investigated. The optimum moisture content that met the landfill liner condition was obtained when the ratio of CMDS: bentonite: cement was 1: 0.5: 0.3 in a lab-scale. The relative compaction was measured in 90.1%, which results for construction field have been generally acceptable. In this study, a large-scale Lysimeter($1.0m{\times}1.5m{\times}2.0m$) was used to simulate the effects of the layer on the freeze/thaw by -20 average temperature. The mixture after freezing/thawing showed compressive strength more than $5kg/cm^2$, which was satisfied with EPA standards. Initial permeability of CMDS was $7.10{\times}10^{-7}cm/s$ and permeability its mixture after freezing/thawing was increased to $9.80{\times}10^{-7}cm/s$. The change of temperature in the layers rises and falls with linear and temperature gradient keep maintain the present state. Moisture contents in the layers have not been radically changed. Through the leaching test determined by KSLT method, it was found that heavy metals excluding Zn and Ni were not leached out or leached out less than the standards during 7 cycles of freezing/thawing process. Since it shows the increased permeability about 1.5 times and slight change in moisture content, but it was satisfied with EPA standar through 7 cycles of freezing/thawing process, this mixture can be applied as a liner in landfill final cover system.

• Microbiology and Biotechnology Letters
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• v.31 no.4
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• pp.377-382
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• 2003

Purification of methioninase resulted in a yield of 69%, and SDS-PAGE analysis of the purified product revealed a single band of approximately 43 kDa in molecular weight. in vitro experiments with cancer cells incubated in methionine-free media demonstrated an increase in $^{11}$ C-methionine uptake to 25.8$\pm$1.1% at 6 hr, 31.8$\pm$0.8% at 24 hr, and 62.2$\pm$0.6% at 48hr, compared to controls. Treatment of the cancer cells with purified methioninase showed no decrease in survival after a 2 hr incubation with 0.01 U/ml, but survival of RR1022 cells decreased 30% after 24 to 48 hr incubation. SKOV-3 cells showed a 5% and 14% decrease in survival with 0.1 and 1 U/ml methioninase after 24 hr. After 48hr survival decreased 15% and 24% with 0.1 and 1 U/ml methioninase. Measurements of $^{11}$ C-methionine uptake in RR1022 cells demonstrated no change at 2 hr, but a 13.7$\pm$4.7% and 40.7$\pm$2.6% increase in uptake at 24 and 48 hr, respectively. SKOV-3 cells also showed no change at 2 hr, but had a 17.7$\pm$7.2% and 38.9$\pm$4.9% increase in $^{11}$ C-methionine uptake after 24 hr and 48 hr treatment with methioninase, respectively. $^{11}$ C-methionine PET imaging revealed clear visualization of both the tumors and contralateral infectious lesions. Administration of rMET appeared to result in a slight increase in tumor:nontumor contrast on $^{11}$ C-methionine PET images. Injection of purified methioninase also produced PET images where tumor uptake was higher than that of infectious lesions.

• Korean Journal of Ecology and Environment
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• v.33 no.4 s.92
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• pp.319-327
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• 2000

The feeding behavior of 1-year-old silver carp, Hypophthalmichthys molitrix (Val.) on phytoplankton species in a shallow hypertrophic lake was studied from 22 May to 18 September, 1997. Over the experimental period, the filter-pore sizes of the fish, the total biomass of the phytoplankton and the water temperature in each enclosure changed little with time. The fish biomass in each enclosure increased with time, while their percentage of weight gain correlated negatively to the stocking density, due perhaps to competition for prey. An analysis of gut contents of silver carp showed a strong similarity between the algal communities in the foregut and the water, and was significant for the fish enclosure with a low density (p<0.05). The presence of silver carp rarely suppressed the abundance of phytoplankton such as Oscillatoria, Anabaena and Melosira even at high ingestion levels. There were weak relationships between the IU values of each phytoplankton and the selectivity of fish on them (r = 0.001, p>0.5). There was no doubt that the silver carp fed unselectively when cyanobacteria populations were high, even though the selectivity index for diatoms was slightly higher than those for cyanobacteria, green algae and cryptomonads. Improvements in methodologies are needed to clearly understand and generalize the feeding behavior of silver carp.

• Journal of the Korean Institute of Landscape Architecture
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• v.14 no.2
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• pp.69-80
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• 1986

In order to analyse the color preference quantitatively, specially with reference to the subjects in the age of twenties, 100 subjects(M=50, F=50) that unconsidered other factors were adopted and responded to 4 items of the questionaire. The item no. 1 was to investigate the most prefered color on the white background, no. 2 was to most preferred stimulation -level of lightness in the same hues, no. 3 was to most prefered color on 5 different backgrounds -grey, blue, pink, yellow, and yellow green-, and no. 4 was same as no. 3 but with different color-arrangement Materials for item 1 and 3 were made with transparent acryl-boards(30cm$\times$30cm), on which 16 color chips arranged on circle, for item 4 on lattice, and for item 2 with 16 white boards(8cm$\times$21cm), on which 7 color chips of different lightness-level arranged. Reflectance(Y) and color coordinate(x, y) of all color chips measured with color difference meter were transfered into wavelength(nm), exitation purity(%), and Munsell's value. The results may be summarized as follows: 1) Most prefered color was bluish green with wave1ength about 500nm. As increasing of exitation purity of color, more prefered. 2) When there were 7 different levels of lightness in the same hues, the relationship between the number of preference and the stimulation was inverted U-shaped. 3) With changing the background -color, the prefered colors were contrasting when backgrounds were low or high intensity-stimulation and familiar colors when backgrounds were medium intensity.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.2
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• pp.137-143
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• 2013

This study is to develop the production method of stepwise dilution gas for the evaluation of complex odor concentration by orifice tube. The basic orifice tube for 10 and 30 times of dilution sample was made at first, and with the combination of the basic orifice tubes we can continuously manufacture the stepwise dilution sample gas for air dilution sensory test ; 10, 30, 100, 300, 1,000, 3,000 times etc. The hole size of orifice tube was 0.84 mm for 10 times of dilution sample, and was 0.34 mm for 30 times. Dilution sample gas made with the basic orifice tube have an excellent reproducibility, 2%RSD. In addition, over 90% of correlation was shown between the sample made by the orifice tube and the sample by the syringe dilution method. Because there was no concentration drift of dilution gas with changes of connected pump flow, the basic orifice tube could be mounted directly with a vacuum suction box, and could be used simply as a tool for the evaluation of odor, especially on site.

• Tuberculosis and Respiratory Diseases
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• v.46 no.4
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• pp.512-522
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• 1999

Background: Due to the paucity of suitable donor organs for lung allotransplantation, a number of techniques have been developed to improve the lung preservation. Ultrastructural studies of the morphologic changes of the flushing, preservation and reperfusion injury in donor lungs have rarely been reported. Methods: Adult dogs (n=46) were matched as donors and recipients for the single lung transplantation. The donor lungs were preserved after flushing with preservation solution and transplanted after 20-hours of preservation at $10^{\circ}C$. Ultrastructural features of the lung were examined after flushing, preservation and 2 hours after lung transplantation (reperfusion) respectively. Results: Electron microscopy after flushing showed focal alveolar collapse and mild swelling of type I epithelial cells. After preservation both type I epithelial cells and endothelial cells were swollen and destroyed focally. The endothelial cells showed protrusion of tactile-like structures into the lumina, blebs or vacuoles of the cytoplasm After reperfusion the lung tissue showed fibrin material in the alveoli, prominent type I epithelial cell swelling with fragmented cytoplasmic debris and marked endothelial cell swelling with vacuoles or tactile-like projections. The alveolar macrophages showed active phagocytosis. Scanning electron microscopic examination of the pulmonary parenchyma showed focally alveolar collapse and focal consolidation after the preservation and more prominent changes after the reperfusion procedure. The lungs preserved with low potassium dextran glucose solution, with additional prostaglandin $E_1(PGE_1)$ and verapamil(VP) showed relatively well preserved ultrastructures compared with those which were preserved with modified Euro-Collins or University of Wisconsin, and with additional $PGE_1$ and/or VP. Conclusion: The ultrastructural changes associated with flushing were mild in severity, the donor lungs were injured during the preservation, and further damage was occurred during the reperfusion. The reperfusion injury resulted in prominent pulmonary parenchymal alterations with a pattern of acute lung injury.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2011.03a
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• pp.29-29
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• 2011

아라미드 섬유는 열에 강한 튼튼한 방향족 폴리아마이드 섬유이다. 아마이드는 "85%이상의 아미드(CO-NH)기가 두 개의 방향족 고리에 직접 연결된 합성 폴리아미드로부터 제조된 섬유"로 정의된다. 아라미드 섬유는 크게 파라계와 메타계로 대별되는데 본 연구에서 사용한 파라계 아라미드는 인장강도, 강인성, 내열성이 뛰어나며 고강력 고탄성률을 지니고 있다. 일반적인 유기 섬유와는 다른 우수한 성질을 바탕으로 부직포, UD laminatig, staple 등의 형태로 크게 섬유보강 고무 복합재료 등의 각종 복합재료, 로프, 케이블, 방탄방호용과 같은 산업자재의 용도로 자동차, 우주항공, 정보통신, 국방, 등 다양한 관련 산업분야에서 사용이 확대되고 있는 고부가 소재이며 가격대비 성능비가 우수하기 때문에 세계적으로 산업용 섬유 및 초고성능 섬유시장에서 비중이 증가될 것으로 예상되고 있다. 본 연구에서는 Para-Aramid 필라멘트를 이용하여 ATY를 생산할 때 제조공정조건에 따른 ATY 물성을 알아보고 고강도를 요구하는 방화복, 고무 보강용 섬유 등의 소재에 맞는 ATY 사가공 최적공정조건을 도출하여 체계화된 data-base를 구축하여 생산성 향상 및 품질개선과 함께 산업자재용 직물개발에 응용하고자 한다. 아라미드를 ATY로 제조할 경우, 표면에 생기는 loop로 인하여 타소재와 접착시, 접착제 담지 성능이 향상되어 접착력이 상승되는 반면, 아라미드 ATY가 기존의 아라미드의 물성보다 저하되는 약점을 가지고 있으므로 이를 보완하기 위해 본 연구에서는 ATY 제조공정에서 중요 공정인자인 사속, heater 온도, over feed ratio를 변화시켜 시료를 제조하여 이들의 물성을 분석하여 최적의 물성을 갖는 ATY 사가공 공정을 도출함으로써 물성이 저하되는 문제를 보완 가능할 것으로 기대된다. 물성분석은 강신도, 초기탄성률을 각각 측정하여 인장특성을 확인하였으며, 습열수축률과 건열수축률을 측정하여 시료의 열수축률에 대해 측정을 하였다. 표면의 루프 발현 정도를 보기 위하여 Crimp Rigidity(CR%), 형태 불안정성(instability)등을 측정하였으며, 영상 현미경 시스템을 사용하여 ${\times}40$ 배율로 표면특성을 측정하였다.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2012.03a
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• pp.62-62
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• 2012

지구온난화 및 환경오염의 영향으로 선진국을 중심으로한 환경규제가 심해지면서, 홈 텍스타일 분야에서는 세계 패션 트렌드 및 소비자 선호에 부응한 친환경 섬유소재 개발, 웰빙 시대에 적합한 기능성 및 고감성 제품개발을 통한 차별화가 요구되고 있다. 최근의 섬유산업의 동향도 인체에 무해한 천연적인 섬유소재에 많은 관심이 증대됨에 따라 개인의 건강 뿐만 아니라 환경을 생각하는 생활패턴인 친환경섬유의 개발이 새로운 트렌드로 떠오르고 있는 실정이다. 헴프는 일년생 식물로서 학명은 Cannabis sativa L.이다. 헴프섬유의 장점으로 내구성 및 내수성, 항균성 등이 우수한 것으로 보고되고 있으나 양질의 원료 확보, 세섬도 추출 기술 및 combing 기술 등의 부족으로 100% 헴프 세 번수 방적사의 제조가 어려워 주로 면섬유와의 혼합소재로 제조되어 왔다. 최근 들어, 친환경 소재로서 박테리아 성장 억제 기능을 가진 재생섬유인 Tencel 소재를 이용하여 stiff한 Hemp의 성질에 유연성을 추가하여 촉감을 개선함과 동시에, Tencel과 Hemp를 혼용함으로써 soft touch부터 harsh touch까지 혼용율에 의한 다양한 감성을 느끼게 함으로써 용도의 다양화 추구가 시도되어 왔다. Hemp의 거친 느낌을 완화시키고 Tencel의 박테리아 억제 기능과 Hemp의 항균기능, 방충, 탈취기능이 상호 보완되어 친환경적이고 위생적인 다용도 홈 인테리어 및 가구용 직물 등의 제품으로 Hemp/Tencel 복합사가 많이 사용되고 있다. 본 연구는 Hemp와 Tencel의 혼용율의 변화에 따른 복합사의 물리적 특성을 확인하기 위하여 천연복합 태번수 방적사 최적 사설계 이론을 적용하여 Hemp 섬유 혼용율에 따른 사의 물성분석을 함으로써 Hemp/Tencel 방적사 최적 공정 조건을 결정하기 위한 사설계 이론 결과와 실험결과를 비교 분석하고자 한다. 최적 천연 Hemp복합방적사 사설계의 이론화 및 사 물성 DB화 그리고 태번수 Hemp사의 물성분석 및 이들을 DB화 함으로써 가구용 직물로 많이 사용되는 친환경 Hemp 소재사의 방적성 향상을 꾀하고자 한다. 이를 위해서 제조한 방적사의 Dry heat shrinkage와 Wet heat shrinkage를 측정하여 확인하였고 인장시험기를 이용하여 Tenacity, Initial Modulus, breaking strain을 측정 분석하였다. 방적사의 표면 특성은 영상 현미경 시스템을 사용하여 ${\times}40$ 배율로 측정하여 확인하였다.