• Journal of the Korean Institute of Educational Facilities
• /
• v.13 no.3
• /
• pp.48-55
• /
• 2006

This paper considered the situation of the school building facilities in the university classified by the campus characteristics. Data were collected from 224 universities campus of 180 4 year colleges. The results are as follows: 1) The floor area of school building facilities increases continuously in 2001-2003 in the campuses studied. The floor area of school building facilities per 1 student increase $15.85m^2$ in 2001, $17.62m^2$ in 2002, and $17.79m^2$ in 2003. 2) The floor area of school building facilities is distributed widely, also the floor area of school building facilities is below $130,000m^2$ and the floor area per 1 student is below $23m^2$ in 75% of the campuses studied. 3) The floor area of school building facilities per 1 student increases $16.07m^2$ in 2001, $17.41m^2$ in 2002 and $17.62m^2$ in 2003. 4) The floor area of school building facilities per 1 student is large but tends to decrease every year in the university of education. Medical, arts and physical type campus has the large floor area per 1 student and the distribution of area is wide owing to the campus having a hospital. The floor area per 1 student is large and the distribution of area is wide in the sub campus.

• Journal of the Korean Society for Precision Engineering
• /
• v.28 no.3
• /
• pp.315-322
• /
• 2011

High-accuracy micropatterns such as V-shaped microgrooves are increasingly in demand for various engineering areas. And the technical trend goes for large surface areas in precision machining technology. So micropatterns with large surface areas are expected to play an increasingly important role in today's manufacturing technology In this study, we focused on developing machining technologies. First, a machine vision system for precise tool setting is developed. Second, an on-machine measurement (OMM) system for large-area measurement is implemented. And also software for tool path generation and simulation is developed. With these technologies we fabricated large-surface micropatterns in an electroless nickel-plated workpiece with single-crystal diamond tools and a 32-in, $675mm{\times}450mm$ mold with tens of V-and pyramid-shaped micropatterns.

• Communications for Statistical Applications and Methods
• /
• v.8 no.2
• /
• pp.407-416
• /
• 2001

Sample surveys are usually designed and analyzed to produce estimates for a large area or populations. Therefore, for the small area estimations, sample sizes are often not large enough to give adequate precision. Several small area estimation methods were proposed in recent years concerning with sample sizes. Here, we will compare simple Bayesian approach with Bayesian prediction for small area estimation based on linear regression model. The performance of the proposed method was evaluated through unemployment population data form Economic Active Population(EAP) Survey.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2010.02a
• /
• pp.291-291
• /
• 2010

Organic solar cells have attracted much interest due to the potential advantage of the lightness, simple solution processing and flexibility. Until recently, the focus of organic solar cells research has been on optimization of material processing to improve the power conversion efficiency. However, area scaling is an important position for alternative to the market dominating solar cells. Spray deposition technologies have advantage of less material wastage and possibility of large scale photoactive area coating when compared with spin coating process. We investigated the performance of organic solar cells as a function of active area using two types of deposition process. The commonly used process is spin coating which can be fabricated organic materials deposition for devices. Spray deposition process compare with spin coating for large-area organic solar cells. The spray deposition organic layer shows excellent performance up to the active area of $4\;cm^2$ with the PCE of ~3.0 % under AM.1.5 simulated illumination with an intensity of $100mW/cm^2$. This indicates that the spray deposition process can be used as a mass production process for evaluating large-area organic solar cells.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2012.08a
• /
• pp.319-320
• /
• 2012

Large aperture optical modulator called optical shutter is a key component to realize time-of-flight (TOF) based three dimensional (3D) imaging systems [1-2]. The transmission type electro-absorption modulator (EAM) is a prime candidate for 3D imaging systems due to its advantages such as small size, high modulation performance [3], and ease of forming two dimensional (2D) array over large area [4]. In order to use the EAM for 3D imaging systems, it is crucial to remove GaAs substrate over large area so as to obtain high uniformity modulation performance at 850 nm. In this study, we propose and experimentally demonstrate techniques for backside etching of GaAs substrate over a large area having high uniformity. Various methods such as lapping and polishing, dry etching for anisotropic etching, and wet etching ([20%] C6H8O7 : H2O2 = 5:1) for high selectivity backside etching [5] are employed. A high transmittance of 80% over the large aperture area ($5{\times}5mm^2$) can be obtained with good uniformity through optimized backside etching method. These results reveal that the proposed methods for backside etching can etch the substrate over a large area with high uniformity, and the EAM fabricated by using backside etching method is an excellent candidate as optical shutter for 3D imaging systems.

• The KIPS Transactions:PartA
• /
• v.16A no.1
• /
• pp.17-26
• /
• 2009

Large-scale wireless sensor network are expected to play an increasingly important role for the data collection in harmful area. However, the physical fragility of sensor node makes reliable routing in harmful area a challenging problem. Since several sensor nodes in harmful area could be damaged all at once, the network should have the availability to recover routing from node failures in large area. Many routing protocols take accounts of failure recovery of single node but it is very hard these protocols to recover routing from large scale failures. In this paper, we propose a routing protocol, which we refer to as LSFA, to recover network fast from failures in large area. LSFA detects the failure by counting the packet loss from parent node and in case of failure detection LSFAdecreases the routing interval to notify the failure to the neighbor nodes. Our experimental results indicate clearly that LSFA could recover large area failures fast with less packets than previous protocols.

• Journal of the Korean Society of Food Culture
• /
• v.11 no.4
• /
• pp.431-438
• /
• 1996

The dietary intake of nutritional elements by Koreans as determined by the Ministry of Health and Welfare's National Nutrition Survey have been reported for $1969{\sim}1993$. But these data were based on not dish but food. Therefore, the purpose of this study was to compare dish sources of energy and macronutrients (carbohydrate, fat, protein) in the diets of three area (large city, small city and rural). Dish sources were evaluated from two-day record obtained in the secondary analysis of the 1993 Korean National Nutrition Survey. The result, large city and small city had higher fat and protein intake than did rural. Otherwise, carbohydrate intake among rural was higher than those among large and small city (p<0.05). The primary dish source of energy and macronutrients was cooked rice for all area. The percentage of cooked rice in daily carbohydrate intake was 52.64% for nationwide, 48.40% for large city, 50.52% for small city, 61.79% for rural. The cumulative percent of top 10 dish sources to carbohydrate for large city, small city, rural were 78.02%, 81.16%, 85.69%, respectively. These was higher than cumulative percent of other macronutrients. The milk as good protein source ranked 3 for large city, 6 for small city, 22 for rural. The major dish sources to fat were cooked rice and pork that prepared by various cooking way. These results show that the major dish sources of energy and macronutrients were cooked rice based of Korea traditional consumption pattern. The most of nutrient intake consumed some dishes for all area. The dish consumption pattern was generally similar between large and small city. But rural was different from other area. Threfore, nutrition educations and interventions should be targeted to each area and should be attended with studies that comparision of dish sources to nutritional elements by specific age-sex groups.

• Transactions on Electrical and Electronic Materials
• /
• v.9 no.2
• /
• pp.73-78
• /
• 2008

We investigated for comparison of large-area i-a-Si:H and p-a-SiC:H film quality like thickness uniformity, optical bandgap and surface roughness using both ICP-CVD and PECVD on the large-area substrate(diameter of 100 mm). As a whole, films using ICP-CVD could be achieved much uniform thickness and bandgap of that using PECVD. For i-a-Si:H films, its uniformity of thickness and optical bandgap were 2.8 % and 0.38 %, respectively. Also, thickness and optical bandgap of p-a-SiC:H films using ICP-CVD could be obtained at 1.8 % and 0.3 %, respectively. In case of surface roughness, average surface roughness (below 5 nm) of ICP-CVD film could be much better than that (below 30 nm) of PECVD film. HIT solar cell with 2 wt%-AZO/p-a-SiC:H/i-a-Si:H/c-Si/Ag structure was fabricated and characterized with diameter of 152.3 mm in this large-area ICP-CVD system. Conversion efficiency of 9.123 % was achieved with a practical area of $100\;mm\;{\times}\;100\;mm$, which can show the potential to fabrication of the large-area solar cell using ICP-CVD method.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.36 no.2
• /
• pp.136-142
• /
• 2023

In the past, the efficiency of solar cells had been increased in order to increase the efficiency of solar modules. However, in recent years, in order to increase output in the solar industry and market, the competitiveness of solar cells based on large-area solar cells and multi-bus bar has been increasing. Multi-busbar solar module is a technology to reduce power loss by increasing the number and width of the front busbar of the solar cell and reducing the current value delivered by the busbar by half through half-cutting. In the case of the existing M2 (156.75×156.75 mm²) solar cell, even with a half-cut, power loss could be sufficiently reduced, but as the area of the solar cell is enlarged to more than M6 (166×166 mm²), the need for more divisions emerged. This affected not only solar cells but also inverters required for module array configuration. Therefore, in this study, the electrical characteristics of a large-area solar cell and after division were extracted using Griddler simulation. The output characteristics of the module were predicted by applying the solar cell parameters after division to PSPice, and a guideline for the large-area solar module design was presented according to the number of divisions of the large-area solar cell.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.18 no.3
• /
• pp.307-314
• /
• 2009

Large area micro pattern replication has promising application potential in many areas. Rolling imprint process has been demonstrated as one of the most competitive processes for such micro pattern replication, because it has advantages in low cost, high throughput and high efficiency. In this paper, we developed a prototype of roll-to-flat(R2F) thermal imprint system for large area micro pattern replication process, which is one of the key processes in the fabrication of flexible displays. Experimental tests were conducted to evaluate the feasibility of system and the parameters' effect on the process, such as flat mold temperature, loading pressure and rolling speed. 100mm $\times$ 100mm stainless steel flat mold and commercially available polycarbonate sheets were used for the tests. The experimental results showed that the developed R2F system is suitable for fabrication of various micro devices with micro pattern over large area.