• Korean Journal of Construction Engineering and Management
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• v.1 no.1 s.1
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• pp.80-86
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• 2000

The future costs of energy and the cost of the repair of apartment buildings are expected to rise continuously in proportion to the initial costs. Therefore it has become important for these increasing costs to be incorporated and reflected in the design of the building. Systems such as structure and services for the buildings remain constant, but a number of the walls and windows can vary and thus have a major influence on the total construction and running costs of a building. The critical factor in the apartment unit design for the optimization of life cycle cost (LCC) is the ratio of the x and y axis of the walls in the unit plan. This paper demonstrates how to achieve the optimal size and thus optimize the LCC of the building.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39A no.5
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• pp.220-228
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• 2014

ESPAR(Electronically Steerable Parasitic Array Radiator) antenna is the technique for overcoming the problems of space limitation and energy efficiency due to the multiple RF-chain. Conventional MIMO system with multiple antenna requires a large number of RF-chain for transmitting the multiple data because it transmits the data in proportion to the number of antenna. Beamspace MIMO system using the ESPAR antenna which has single RF-chain was proposed for solving the problems caused by using the multiple antenna and RF-chain. In this paper, therefore we propose 2x2 beamspace MIMO system using the 16, 64-QAM modulation and evaluate the performance of this system to reveal that it is possible that beamspace MIMO system can use not only PSK modulation but also QAM modulation. We confirm that QAM symbol can be generated by adjusting reactance of parasitic elements and making reactance set and also we confirm that performance of beamspace MIMO system is similar to the conventional MIMO system by transmitting the QAM symbol made by reactance set through the simulation.

• Nutrition Research and Practice
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• v.13 no.6
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• pp.543-554
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• 2019

BACKGROUND/OBJECTIVES: The elderly are reported to have a high prevalence of nutritional anemia when they have lower intakes of nutrients or chronic diseases. This study was conducted to compare nutritional status according to nutritional anemia and to determine associations between nutritional anemia and chronic diseases in Korean elderly. SUBJECTS/METHODS: This study utilized data on 3,258 elderly aged ${\geq}65$ years gathered during the $6^{th}$ Korea National Health and Nutrition Examination Survey 2013-2015. Subjects were divided into nutritional anemia (NA) group (n = 415) and non-NA group (n = 2,843) by hemoglobin concentration. Nutrient intakes were assessed using dietary intake data obtained using the 24-hour recall method. The odds ratios (ORs) for nutritional anemia by chronic diseases were determined. Statistical analysis was performed using SPSS Ver. 23.0. RESULTS: Of 3,258 subjects, 12.7% had nutritional anemia. Intakes of potatoes, pulses, and mushrooms by males and potatoes, fruits, meats, eggs, and seafood by females were significantly lower in NA group than in non-NA group. The proportion of the subjects whose intakes of protein, vitamin A, vitamin $B_1$, vitamin $B_2$, niacin, and iron less than estimated average requirement (EAR) were significantly higher in NA group compared to non-NA group. After adjusting for age, the number of family members, energy intake, and alcohol drinking, ORs for nutritional anemia in the subjects with diabetes and myocardial infarction or angina pectoris were significantly higher by 1.74 times and 1.59 times as compared to the subjects without those diseases, respectively. However, ORs for nutritional anemia in the subjects with obesity, abdominal obesity, and hypertriglyceridemia were significantly lower by 0.64 times, 0.60 times, and 0.59 times as compared to the subjects without those diseases, respectively. CONCLUSIONS: The results of this study suggested that nutritional management should be done to enable the Korean elderly to consume foods with high hematopoietic nutrients density to prevent nutritional anemia. Korean elderly need to make regular efforts to check for nutritional anemia.

• Korean Journal of Community Nutrition
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• v.29 no.3
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• pp.222-233
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• 2024

Objectives: This study was conducted to investigate the status of total sugar intake and contributing foods in Korea according to age groups. Methods: This study used 24-hour dietary recall data from the 8th Korea National Health and Nutrition Examination Survey (2019-2021) to investigate the nutritional and total sugar intake status among Koreans. A total of 18,338 research participants (≥3 years old) were included in this study. To analyze the types of foods contributing to total sugar intake, these foods were categorized into 15 types. Moreover, we examined the total sugar intake and ranked the most consumed foods by age groups (3-11 years, 12-18 years, 19-34 years, 35-49 years, 50-64 years, over 65 years). A survey procedure was employed for statistical analysis. Results: The energy intake ratio from total sugars was approximately 12%-15%, which was within the recommended range. However, the proportion of individuals consuming total sugar exceeding 20% of their total caloric intake is nearly 20%, raising concerns about excessive sugar consumption. Furthermore, the percentage of participants whose intake of sugar from processed foods exceeded 10% of their total calories was highest in the 12-18 age group at 37.1%, followed by the 3-11 age group at 35.2%, and the 19-34 age group at 34.0%. Carbonated drinks, cola, and cider were the primary foods consumed by children and adolescents (3-18 years old) and young adults (19-34 years old). For middle-aged and older adults, mixed coffee with sugar and cream was a prominent contributor to sugar intake. Conclusions: This study investigated sugar consumption patterns among Koreans, finding the principal foods contributing to this intake. Identifying these contributors is pivotal, given their potential impact on public health.

• Korean Chemical Engineering Research
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• v.47 no.4
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• pp.436-440
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• 2009

This study demonstrates the use of a chemical lung containing potassium superoxide to convert carbon dioxide in air to oxygen. In order to reduce its extremely high reactivity, potassium superoxide was first mixed with calcium hydroxide and then combined at various ratios with polysiloxane. Silicone polymer used here served as both a water repellent and the polymer matrix. In general, the amount of carbon dioxide captured as well as that of oxygen produced increased as the proportion of potassium superoxide in the chemical lung increased. FT-IR spectroscopy revealed that the Si-O bond in chemical lung appeared at $1,050cm^{-1}$ and absorbance of chemical lung containing higher amounts of silicone was higher than that of chemical lung containing lower amounts. These results indicate that such a chemical lung may also be a useful sorbent for other acid gases, such as sulfur oxides and nitrogen oxides.

• The Korean Journal of Zoology
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• v.22 no.4
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• pp.153-164
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• 1979

A total of 352 specimens of congeneric species of Agkistrodon was collected and morphometric analysis and starch-gel electrophoresis were carried out in order to investigate the taxonomic status of this genus. The results obtained in this study are as follows: Morphometric analysis 1. Three species are recognized based on Gloyd's criteria. There was no specimen that was doubtful to classify correctly. Therefore, it seems that Gloyd's morphological characters are good criteria to identify each species. 2. All three species are sympatric at two localities (Mt. Seolag, Gangwon-do, and Mt. Deogyu, Jeonra-bugdo) and A. caligino년 and A. b. brevicaudus are sympatric at Gwangneung and Mt. Yongmun, Gyonggi-do. No hybrids were found in these sympatric localities. 3. Notable sexual dimorphism was found in meristic characters. 4. A. saxatilis has signicantly more number of ventrals and shorter tail ratio than other two species. 5. There were no significant meristic character differences between A. caligino년 and A. b. brevicaudus. Genetic analysis 1. Among 26 loci investigated, 12 loci (46.1%) were identical in their mobility, 4 loci (15.4%) were nearly identical with minor frequency differences, and 10 loci (38.5%) showed interspecific mobility difference. 2. The average proportion of polymorphic loci was 9.03%. This is considerably less than that of other vertebrates. 3. The average S and D values between species are .695 and .342 respectively. These values indicate that three taxa are distinct species. 4. A. caliginosus is genetically more related to A. saxatilis than to Agkistrodon, namely A. b. brevicaudus, A. caligino년 and A. saxatilis, as proposed by Gloyd. Far from being mere morphological variants, as suggested by Kang and Yoon (1975), they are highly distinctive evolutionary units.

• Membrane Journal
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• v.31 no.4
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• pp.268-274
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• 2021

One of the chronic problems in the issue of global warming is the emission of greenhouse gases. Carbon dioxide (CO₂), which accounts for the highest proportion of various greenhouse gases, has been continuously researched by humans to separate it. From this point of view, a poly(vinyl alcohol) (PVA)-based copolymer with acrylic acid monomer was utilized in a gas separation membrane in this study. We employed a free radical polymerization to fabricate PVA-g-PAA (VAA) graft copolymer. It was utilized in the form of a composite membrane on a polysulfone substrate. The proper amount of acrylic acid reduced the crystallinity of PVA and increased CO₂ solubility in separation membranes. In this perspective, we suggest the novel approach in CO₂ separation membrane area by grafting and solution-diffusion.

• Plant Journal
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• v.18 no.3
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• pp.28-40
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• 2022

As the proportion of renewable energy generation is expected to increase, public power generation businesses need to actively consider implementing the expansion of biomass mixing, In this study, the biomass co-firing rate is being changed from 0wt.% to 5.0wt.% at 500MW coal-fired power plant, measuring the major operation characteristics of the pulverizer. First, the composition analysis and grinding characteristics of lignocelluosic biomass were examined, and the effect of volume increase on dirrerential bowl pressure difference, motor current, coal spillage, outlet temperature, and internal fire count was analyzed. As the co-firing rate increased, it was confirmed that the difference in the differential bowl pressure, motor current, and coal spillage treated increased, and the outlet temperature was minimal. The number of internal fires is difficult to find a clear correlation, but it has been confirmed that it is highly likely to occur in combination with other driving factors.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.1
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• pp.572-578
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• 2017

Haptic systems help users feel a realistic sensation when they manipulate virtual objects in the remote virtual environment. However, there are communication time delays that may make the haptic system unstable. This paper shows the relationship between communication time delay, properties of a haptic device, and the stability of the haptic system with the first-order hold method in a simulation. The maximum available stiffness of a virtual spring with the first-order hold method is larger than in the zero-order hold method when there is no time delay. However, when the communication time delay is much larger than the sampling time, the maximum available stiffness to guarantee the stability becomes the same, irrespective of the sample-hold methods. Besides, the maximum available stiffness increases in inverse proportion to the communication time delay and in proportional to the damping coefficient of the haptic device.

• Nuclear Engineering and Technology
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• v.55 no.9
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• pp.3268-3276
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• 2023

The practice of identifying the potential zones for mineral exploration in a speedy and low-cost method includes the use of satellite imagery analysis as a part of remote sensing techniques. It is challenging to explore the iron mineralization of a region through conventional methods which are a time-consuming process. The current study utilizes the Hyperion satellite imagery for mapping the iron mineralization and associated geological features in the Irikkur region, Kannur, Kerala. Along with the remote sensing results, the field study and laboratory-based analysis were conducted to retrieve the ground truth point and geochemical proportion to verify the iron ore mineralization. The MC simulation showed for shielding properties indicate an increase in the linear attenuation coefficient with raising the Fe₂O₃+SiO₂ concentrations in the investigated rocks where it is varied at 0.662 MeV in the range 0.190 cm^-1 - 0.222 cm^-1 with rising the Fe₂O₃+SiO₂ content from 57.86 wt% to 71.15 wt%. The analysis also revealed that when the γ-ray energy increased from 0.221 MeV to 2.506 MeV, sample 1 had the largest linear attenuation coefficient, ranging from 9.33 cm1 to 0.12 cm^-1. Charnockite rocks were found to have exceptional shielding qualities, making them an excellent natural choice for radiation shielding applications.