• Architectural research
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• 제18권3호
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• pp.83-90
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• 2016

Senescent effects are the gradual deterioration of function caused by biological aging. Senescent effects on color vision are not clearly understood even after considerable researches. Part of the reason is that the color vision is a complex phenomenon resulting from various factors such as organic systems, and the physical (neuro-optical) and the psychological (experiential) processes of color perception. We performed a field experiment on color perceptional differences due to aging vision. Our experiment was applied to two different groups in South Korea: an experimental group (46 subjects of over the age of 61 years) and a control group (49 subjects in their twenties). The experimental tools are comprised of (1) six gradual yellowing detector board (40%, 50%, 60%, 70%, 80%, 90%); (2) pairs of vivid-strong, vivid-deep, grayish-deep, deep-dull, and bright-light tones of Blue (B) and Purple (P) colors; (3) Red (R), Yellow (Y), Green (G), Blue (B), and Purple (P) colors of dull-tones and pale-tones; and (4) a questionnaire on the semantic differential scales of the color images and color differences. A diagnosis system of gradual yellow vision, developed by the authors for this study, was adapted to generate the color detecting boards. The results are as follows. (1) There are significant differences between the two groups in detecting colors that simulate 40% and 50% of yellow vision. (2) As to the color difference detecting ability between similar tones, the experimental group shows difficulties in pairs of vivid-strong tones and deep-dull tones of the B color. And (3), the emotional responses to the dull tone and the pale tone are not stable in the red, the yellow, blue, and purple. Thus, we empirically demonstrate the specific differences in color perception between the old and young groups.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2005년도 학술발표회(2)
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• pp.1189-1192
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• 2005

Due to their slow degradation properties, hydrophobic organic contaminants in estuarine sediment have been a concern for risks to human health and aquatic organisms. Studies of fate and transport of these contaminants in estuaries are further complicated by the fact that hydrodynamics and sediment transport processes in these regions are complex, involving processes with various temporal and spatial scales. In order to simulate and quantify long-term attenuation of Polycyclic Aromatic Hydrocarbons (PAH) in the Elizabeth River, VA, we develop a modeling approach, which employs the U.S. Environmental Protection Agency's water quality model, WASP, and encompasses key physical and chemical processes that govern long-term fate and transport of PAHs in the river. In this box-model configuration, freshwater inflows mix with ocean saline water and tidally averaged dispersion coefficients are obtained by calibration using measured salinity data. Sediment core field data is used to estimate the net deposition/erosion rate, treating only either the gross resuspension or deposition rate as the calibration parameter. Once calibrated, the model simulates fate and transport PAHs following the loading input to the river in 1967, nearly 4 decades ago. Sediment PAH concentrations are simulated over 1967-2022 and model results for Year 2002 are compared with field data measured at various locations of the river during that year. Sediment concentrations for Year 2012 and 2022 are also projected for various remedial actions. Since all the model parameters are based on empirical field data, model predictions should reflect responses based on the assumptions that have been governing the fate and sediment transport for the past decades.

• 상하수도학회지
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• 제20권4호
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• pp.545-558
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• 2006

The current conditions of large water mains are evaluated by deteriorations and the causes of deterioration are investigated through visual assessments in the field, mechanical tests and analysis of chemical compositions in laboratory for each pipe material, unlined cast iron pipes (CIPs), ductile iron pipes (DCIPs) and steel pipes (SPs) Tubercles and scales from internal and external corrosion of unlined cast iron pipes were identified as the causes of functional performance limitations in large water mains. It is investigated that main causes of internal and external corrosion of water pipes are from lots of depositions of organic and inorganic substances on pipe surface, concentrated pitting, and uniform corrosion by local or global exfoliation or detachment of lining and coatings of DCIPs and SPs. Internal and external corrosion depths of CIPs were higher than those of DCIPs and SPs. Consequently, total corrosion rate summed internal and external corrosion rates of CIPs also were shown to be higher than those of DCIPs and SPs. The failure time from hole generation of CIPs by total corrosion rate was predicted to be taken sixteen years, and DCIPs and SPs were twenty-six years and one hundred and fifty three years. And longitudinal deflection of investigated water mains were not happened and mechanical strengths such as tensile strength, elongation, and hardness also were mostly suited to Korea Standards. It was thought that the weakness of tensile strength of one sample(S-11) was, however, due to higher carbon contents(%) in CIPs. Pipe deterioration score of S-46 was 55.2 and was preferentially assessed to be rehabilitated.

• Asian-Australasian Journal of Animal Sciences
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• 제6권1호
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• pp.139-145
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• 1993

Biogas created from animal waste is a precious energy source. A practical and successful utilization of the biogas is not easy, because there lie some difficulties in biogas production and facilities investment. In this study, the requisites for a successful biogas utilization were discussed. The production results obtained in the previous operation of anaerobic digestion plant were used for the simulation. When the slurry heating was designed for constant biogas generation, depreciation costs of the facilities amounted 1,175,000 yen per year, and biogas productions at $24.5^{\circ}C$, $30.0^{\circ}C$ and $35.5^{\circ}C$ were $16.8m^3$, $17.6m^3$ and $25.1m^3$, respectively. Removal ratios of organic matters were not so high. At $35.5^{\circ}C$, energy value of the biogas produced was estimated 125.5 Mcal per day, and the following heat loss (y Mcal/day) was brought about by the temperature difference ($X^{\circ}C$) between the digester and atmosphere; y = 0.769X - 5.375. The costs of biogas production per cow were assumed to decrease according to enlargement of feeding scale, especially on scales of more than 30 cows. On recent levels of costs and prices of energy in Japan, they were nearly equal to 2 to 3 fold of the price of municipal mixed gas when a anaerobic digester was compulsorily heated and kept at $30.0^{\circ}C$ or $35.5^{\circ}C$.

• 한국작물학회:학술대회논문집
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• 한국작물학회 1999년도 추계 학술대회지
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• pp.25-79
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• 1999

To evaluate the historical changes and future counterplan of food culture in Korea . the following were surveyed : the scale of foodseivice industry. the consumer attitude on functional health food. the fancy and using frequency of fastfood in the growing generation, the actual state on use of imported food. consumer opinions in selecting factor of functional and organic foods. the actual state and consumer attitude on the imported foods, long-term prospect of food service industry in futures. the production of food rubbishes and their reusing rates. the production scales and toxicity problems of agricultural medicines including the postharvest agricultural medicine. the consumer anxiety such as potential environmental and human health risks associated with GMOs (genetically modified organisms) and the import state of GMOs, long-term prospect of population increase in world, and aged population of over 65 years and their social index in Korea, self-supporting rate and national security of food in Korea. the prospect for demand and supply of grains in Korea and world. decrease of the farming population and the decrease problem of agricultural productivity. the problem on the introduction of direct payment system for a farmhouse, and other social problem etc. In cases of 1996, self-supporting rate of food in Korea was the lowest as $26.4{\%}$ in the world but those countries such as USA, UK France, Canada and Denmark were $134.0{\%}\;122.0{\%}$. $190.0{\%}$. $179.0{\%}\;and\;134.0{\%}$, respectively. in 1997 Therefore. our food security appeared as a very serious problem in a viewpoint of the national security That's why this very important Symposium will be held by agriculture-related three Societies to see the last year of 1999 out and the new millennium in.

• Journal of Plant Biology
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• 제11권4호
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• pp.9-20
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• 1968

In general there are few cases which were caused by lightening and no fire was observed to have been caused but by artificial or accidental fires during preliminary survey. And then the most scales of burning in Korea are like the fig. 2. Temperature 5 cm apart from flame at the burning site were known to range from 165$^{\circ}$to 20$0^{\circ}C$ in surface fire on Myozangdong, pine-quercus dominant community and from 120$^{\circ}$ to 145$^{\circ}C$ in surface fire of Wolwoonni, Mischanthus dominant area and from 120$^{\circ}$ to 14$0^{\circ}C$ in ground fire of Wangzinkun, Mischanthus dominant, respectively. Through the preliminary survey, fire indicater plants in Korea were confirmed as Mischanthus coreensis Hack and Carex alterifolia Franch. The plants of highest frequency appeared in the burnt sites were known to as Potentilla cryptotaeniae Max, Mischanthus coreensis Hack, Carex alterifolia Franch and Artemisia brachyphylla Kitamura. Lespedezas were proved as one of the fire tolerant and Pinus densiflora was found out as the lowest intolerant plant to fire. The acidity of burnt soil was decreased according to the considerable amount of ash left on the ground. The acidity of surface soil was more decreased than the below 10cm of soil. The chemical composition(NO3, P, K, Mg, Total-N and Organic-C) of burnt soil was more increased than those of the unburnt sites. And the population changes of soil microflora seemed to have a certain tendency. The population of soil microflora was increased a little according to climatic conditions. Also there was an initial decrease in the population of microflora followed immediately by a significant increase.

• 한국해양학회지
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• 제26권3호
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• pp.255-261
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• 1991

중앙 북부 태평양의 두 개의 해산(Horizon guyot와 Magellan rise) 상의 수층에서 박테리아의 생체량과 생산력이 1987년 3월에 조사되었다. 이 기간에 관찰된 표층수의 박테 리아 개체수는 (0.9-2.3$\times$10/SUP 8/l/SUP -1/) 빈영양 해역에서 보고 된 박테리아의 개체수에 비해 낮은 값은 나타냈다. 또한 mesopelagic zone 의 박테리아 개체수도 (대 개 < 5$\times$10/SUP 7/l/SUP -1/) 다른 아열대 지역에서 보고 된 것보다 훨씬 낮았다. 표층수에서의 박테리아 생산력(20-466 ng C l/SUP -1/ d/SUP -1/)또한 다른 빈영양 해 역과 비교시 낮았다. 그러나 표층수의 박테리아 생산력을 이 지역에서 발표된 일차 생 산력과 비교한 경우, 유기물의 이용에 있어서 박테리아의 역할이 중요한 것으로 추정 되었다. 이 연구에서 보고 된 박테리아 생산력의 공간적 분포에 대한 자료는 충분하진 않으나, 매우 빈영양인 수서 환경에서 소규모 그리고 대규모적 공간상의 박테리아 생 산력 분포에 대한 연구의 필요성을 제시하고 있다.

• 청정기술
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• 제24권4호
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• pp.357-364
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• 2018

미세조류 및 거대조류 등 3세대 바이오매스로부터 바이오가스를 생산하는 연구는 다양한 규모의 실험을 통해 수행된 바 있다. 이 논문에서는 3세대 바이오매스 중 거대조류, 즉 해조류 바이오매스로부터 유래된 바이오가스를 이용하는 복합 열병합 발전의 상용화 가능성을 살펴보았다. 이를 위해 고체산화물 연료전지와 가스터빈, 그리고 유기랭킨사이클로 이루어진 산업 스케일의 통합 열병합발전을 상용 공정모사기를 이용하여 설계, 모사하였고, 계산된 열 및 물질수지를 통해 장치의 가격을 추정하고 경제성을 분석하였다. 모사 결과 설계된 열병합발전 공정은 시간당 62.5톤의 건조 갈조류 원료로부터 생산된 36톤의 바이오가스를 이용하여 68.4 MW의 전력을 생산한다. 이 결과를 토대로 다양한 시나리오에 대해 경제적으로 평가하고 균둥화 발전비용(levelized electricity cost, LEC)을 계산하였는데, SOFC의 수명이 5년, 스택 가격이 $$225kW^{-1}$일 때 LEC는 12.26 ¢ $kWh^{-1}$로 기존의 고정 발전과 동등한 수준으로 나타났다.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제25권6호
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• pp.500-509
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• 2022

Purpose: We compared the health-related quality of life (HRQOL) of children and adolescents with functional abdominal pain disorders (FAPDs) and organic abdominal pain disorders (ORGDs). Methods: This was a single-center, cross-sectional, observational study. The PedsQL 4.0 generic cores scales parent proxy-report was administered to parents/caregivers of 130 and 56 pediatric patients with FAPDs and ORGDs respectively on their first visit. The self-reported pain intensity in the patients was assessed using a visual analog scale (VAS) and facial affective scale (FAS). Results: Irritable bowel syndrome was the most prevalent FAPDs, and the most prevalent ORGDs were reflux esophagitis (41.1%) and gastritis associated with Helicobacter pylori (21.4%). There was no difference in HRQOL among patients diagnosed with ORGDs and FAPDs (p>0.05). Patients with ORGDs and FAPDs had lower HRQOL Scale scores than healthy Brazilian and American children's references, with a high proportion of children at risk for impaired HRQOL (p<0.0001). There was no difference in the VAS and the FAS scores between the ORGDs and the FAPDs. FAPDs had a higher prevalence of girls' and couples' disagreement (p<0.02), although poor school performance (p<0.0007) and bullying (p<0.01) were higher in patients with ORGD. Conclusion: This study revealed that there was a difference in impaired HRQOL between patients with ORGDs and FAPDs. Thus, considering the high prevalence of chronic abdominal pain in children, a well-founded treatment plan is necessary for a multidisciplinary cognitive-behavioral Pain management program.

• 천문학회보
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• 제46권1호
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• pp.44.2-45
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• 2021

As implied by the zodiacal light and spacecraft impact measurements, the space between large bodies in our Solar System is filled with interplanetary dust particles (IDPs). IDPs give us deeper insight into the composition and evolution of the Solar System, as well as being a crucial reference for extrasolar research. IDPs can be interpreted as bearers of carbon and organic materials, and thus, their interaction with Earth can be considered as important factors for the birth of terrestrial life. One of the key routes of IDPs entering Earth is via meteoroid streams (Love and Brownlee 1993). The Geminid meteoroid stream is a notable example. Together with its source asteroid (3200) Phaethon, the Phaethon-Geminid stream complex (PGC) (Whipple 1983; Gustafson 1989) can potentially provide information on the properties and evolution of IDPs in near-Earth space. DESTINY+* is a JAXA/ISAS spacecraft planned to launch in 2024 to explore the physical and chemical features of near-Earth IDPs and uncover the dust ejection mechanism of active near-Earth asteroids, especially Phaethon (Arai et al. 2018). Previous studies on the dust ejection mechanism of Phaethon have various degrees of success in explaining the ejection of submillimeter particles and try to recreate the dust replenishment rate of the Geminid stream. However, none of them are satisfactory for explaining the observed Geminid stream, especially for larger particles of a millimeter and centimeter scales. Inspired by the discovery of rotational mass shedding in the Main Belt region (Jewitt et al., 2014), we investigate a dust ejection scenario by rotational instability on Phaethon. Using the N-body integrator MERCURY6 (Chambers 1999; modified by Jeong 2014), we performed a long-term integration of dust particles of various sizes ejected at ~1 m/s. Through this process, we discuss the implications Phaethon's rotation may have on its ejection, the formation and evolution of IDP by this mechanism, and contribute to the DESTINY+ mission.