• Journal of Intelligence and Information Systems
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• v.22 no.4
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• pp.45-67
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• 2016

Given the recent development of smart devices, users are producing, sharing, and acquiring a variety of information via the Internet and social network services (SNSs). Because users tend to use multiple media simultaneously according to their goals and preferences, domestic SNS users use around 2.09 media concurrently on average. Since the information provided by such media is usually textually represented, recent studies have been actively conducting textual analysis in order to understand users more deeply. Earlier studies using textual analysis focused on analyzing a document's contents without substantive consideration of the diverse characteristics of the source medium. However, current studies argue that analytical and interpretive approaches should be applied differently according to the characteristics of a document's source. Documents can be classified into the following types: informative documents for delivering information, expressive documents for expressing emotions and aesthetics, operational documents for inducing the recipient's behavior, and audiovisual media documents for supplementing the above three functions through images and music. Further, documents can be classified according to their contents, which comprise facts, concepts, procedures, principles, rules, stories, opinions, and descriptions. Documents have unique characteristics according to the source media by which they are distributed. In terms of newspapers, only highly trained people tend to write articles for public dissemination. In contrast, with SNSs, various types of users can freely write any message and such messages are distributed in an unpredictable way. Again, in the case of newspapers, each article exists independently and does not tend to have any relation to other articles. However, messages (original tweets) on Twitter, for example, are highly organized and regularly duplicated and repeated through replies and retweets. There have been many studies focusing on the different characteristics between newspapers and SNSs. However, it is difficult to find a study that focuses on the difference between the two media from the perspective of supply and demand. We can regard the articles of newspapers as a kind of information supply, whereas messages on various SNSs represent a demand for information. By investigating traditional newspapers and SNSs from the perspective of supply and demand of information, we can explore and explain the information dilemma more clearly. For example, there may be superfluous issues that are heavily reported in newspaper articles despite the fact that users seldom have much interest in these issues. Such overproduced information is not only a waste of media resources but also makes it difficult to find valuable, in-demand information. Further, some issues that are covered by only a few newspapers may be of high interest to SNS users. To alleviate the deleterious effects of information asymmetries, it is necessary to analyze the supply and demand of each information source and, accordingly, provide information flexibly. Such an approach would allow the value of information to be explored and approximated on the basis of the supply-demand balance. Conceptually, this is very similar to the price of goods or services being determined by the supply-demand relationship. Adopting this concept, media companies could focus on the production of highly in-demand issues that are in short supply. In this study, we selected Internet news sites and Twitter as representative media for investigating information supply and demand, respectively. We present the notion of News Value Index (NVI), which evaluates the value of news information in terms of the magnitude of Twitter messages associated with it. In addition, we visualize the change of information value over time using the NVI. We conducted an analysis using 387,014 news articles and 31,674,795 Twitter messages. The analysis results revealed interesting patterns: most issues show lower NVI than average of the whole issue, whereas a few issues show steadily higher NVI than the average.

• KSBB Journal
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• v.17 no.1
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• pp.73-79
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• 2002

The method to optimize the microbial production of ethanol from CO using Clostridium ljungdahlii was developed. The kinetic parameter study on CO conversion with Clostridium ljungdahlii was carried out and maximum CO conversion rate of 37.14 mmol/L-hr-O.D. and $K_{m}$ / of 0.9516 atm were obtained. It was observed that method of two stage fermentation, which consists of cell growth stage and ethanol production stage, was effective to produce ethanol. When pH was shifted from 5.5 to 4.5 and ammonium solution was supplied to culture media as nitrogen source at ethanol production stage, the concentration of ethanol produced was increased 20 times higher than that without shift. Ethanol production from CO in a fermenter with Clostridium ljungdahlii was optimized and the concentration of ethanol produced was 45 g/L and maximun ethanol productivity was 0.75 g ethanol/L-hr.

• KDI Journal of Economic Policy
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• v.30 no.2
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• pp.157-183
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• 2008

'New Universities for Regional Innovation(NURI)' is a financial aid program designed to promote the development of universities as a major component of Regional Innovation System (RIS). In particular, this program emphasizes the role of regional universities to provide the qualified graduates for the regional economy. This paper is to evaluate the effect of NURI, focusing on the change of graduates' employment. The effect of the program can be evaluated by the quality of graduates' accumulated human capital, and graduates' employment performance represents the graduates' quality evaluated in the labor market. This is also believed to be a good performance indicator of the NURI program. We utilize the graduate employment survey of Korean Educational Development Institute (KEDI), and calculate the graduates' employment rates of the departments that received the financial support of NURI (treatment group). We also calculate the graduates' employment rates of the departments that applied for the support of the NURI program but were not selected (comparison group). By using difference-in-differences method, we compare the change of graduates' employment rates in treatment and comparison groups before and after the program came in effect. Compared with the employment rates in 2004 before the NURI program started, the graduates employment rates improved in both groups in 2005 and 2006. The improvement of the employment rates in the treatment group is larger than that in the comparison group. Moreover, the difference of improvement gets larger in the year 2006 than in 2005, which means those students who were affected more years by the NURI program are more likely to be employed. However, the difference is not statistically significant, and we cannot definetely conclude that NURI showed the desired effect on the quality of the college graduates. We calculate employment rates in two ways; whether to treat going on to graduate education as an employment or not. The result was qualitatively the same in both cases. We also tracked quality of employment by investigating the firm size where the graduates of the treatment group were employed. By utilizing data from the Employment Insurance Fund, we measure the firm size by the number of employees. We did not find any deterioration of employment quality between 2005 and 2006, though it deteriorates in 2007. Therefore, the improvement of employment rates until 2006, though not statistically significant, does not seem to come at the cost of employment quality. The interpretation of this result cannot help being very limited. First, this evaluation covers such a short time period. It only covers two years after the program started, 2005 and 2006. Second, the extent of the improvement in employment rates is not satisfactory considering the amount of financial support, even though it can be argued that the employment has improved since the inception of the program. Subsequent evaluation of the program is required to certify the NURI programs' longer term effectiveness.

• Progress in Medical Physics
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• v.23 no.2
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• pp.81-90
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• 2012

The effect of setup uncertainties on CTV dose and the correlation between setup uncertainties and setup margin were evaluated by Monte Carlo based numerical simulation. Patient specific information of IMRT treatment plan for rectal cancer designed on the VARIAN Eclipse planning system was utilized for the Monte Carlo simulation program including the planned dose distribution and tumor volume information of a rectal cancer patient. The simulation program was developed for the purpose of the study on Linux environment using open source packages, GNU C++ and ROOT data analysis framework. All misalignments of patient setup were assumed to follow the central limit theorem. Thus systematic and random errors were generated according to the gaussian statistics with a given standard deviation as simulation input parameter. After the setup error simulations, the change of dose in CTV volume was analyzed with the simulation result. In order to verify the conventional margin recipe, the correlation between setup error and setup margin was compared with the margin formula developed on three dimensional conformal radiation therapy. The simulation was performed total 2,000 times for each simulation input of systematic and random errors independently. The size of standard deviation for generating patient setup errors was changed from 1 mm to 10 mm with 1 mm step. In case for the systematic error the minimum dose on CTV $D_{min}^{stat{\cdot}}$ was decreased from 100.4 to 72.50% and the mean dose $\bar{D}_{syst{\cdot}}$ was decreased from 100.45% to 97.88%. However the standard deviation of dose distribution in CTV volume was increased from 0.02% to 3.33%. The effect of random error gave the same result of a reduction of mean and minimum dose to CTV volume. It was found that the minimum dose on CTV volume $D_{min}^{rand{\cdot}}$ was reduced from 100.45% to 94.80% and the mean dose to CTV $\bar{D}_{rand{\cdot}}$ was decreased from 100.46% to 97.87%. Like systematic error, the standard deviation of CTV dose ${\Delta}D_{rand}$ was increased from 0.01% to 0.63%. After calculating a size of margin for each systematic and random error the "population ratio" was introduced and applied to verify margin recipe. It was found that the conventional margin formula satisfy margin object on IMRT treatment for rectal cancer. It is considered that the developed Monte-carlo based simulation program might be useful to study for patient setup error and dose coverage in CTV volume due to variations of margin size and setup error.

• Korean Journal of Environment and Ecology
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• v.27 no.1
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• pp.113-126
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• 2013

This study was performed to introduce ecological education program as for reporting the current vegetation state within the remaining trees as ecological golf course and to provide basic data. The survey site was S Golf course, which is located in Woonseodong, Incheon city. Its total area was about $3,298,428m^2$, but the relict forest was about $225,143m^2$. Existing landuse, topological structure, the flora, actual vegetation, and plants community structure survey were performed within the relict forest. As result of comparing and analyzing the existing land use, the relict forest was distributed in the forested areas (89.2%) and around the area (10.8%) which had been bare land and SAMMOK earthen ramparts. There were two courses (Ocean and Hanul) with the relict forests. The ocean course was compared of a natural forest, such as Quercus spp. mixed forest, Quercus acutissima forest, Pinus thunbergii forest within the rock fields, and an artificial forest (Ailanthus altissima-Robinia pseudoacacia forest, Robinia pseudoacacia forest) and Quercus acutissima - Elaeagnus umbellata forest. On the Hanul course, Pinus rigida forest and Robinia pseudoacacia forest were the main vegetation, which were artificial forest. It was the contrast aspect of vegetation species in a natural forest, a restoration forest and an artificial forest, which were Q. spp. mixed forest 26~28 species in a natural forest within the vegetation type per investigation area, 3 Pinus thunbergii forest species, and 5~7 artificial forest species on the Hanul course. Based on these vegetation status, the Ocean course was designed into ecological theme spaces named 'Quercus spp.' indigenous forest, 'Pinus thunbergii' restoration forest and ecological story of 'SAMMOK earthen ramparts'. The Hannul course was designed into an artificial forest observation area of 'Robinia pseudoacacia' and 'Pinus rigida' and a fragrance forest area of 'Robinia pseudoacacia'. At the time of the discussion about the introduction of eco-friendly approval system of golf course, it would be estimated that this survey would work as a major material not only raising awareness of the golf course on the ecological environment but also providing programs that can contribute to the community.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.10 no.6
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• pp.425-433
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• 2000

The stochiometric mix of evaporating materials for the $CuGaTe_2$single crystal thin films was prepared from horizontal furnance. Using extrapolation method of X-ray diffraction patterns for the $CuGaTe_2$polycrystal, it was found tetragonal structure whose lattice constant $a_0 and c_0$ were 6.025 $\AA$ and 11.931 $\AA$, respectively. To obtain the single crystal thin films, $CuGaTe_2$mixed crystal was deposited on throughly etched semi-insulator GaAs(100) substrate by the Hot Wall Epitaxy (HWE) system. The source and substrate temperature were $670^{\circ}C$ and $410^{\circ}C$ respectively, and the thickness of the single crystal thin films is 2.1$\mu\textrm{m}$. The crystalline structure of single crystal thin films was investigated by the photoluminescence and double crystal X-ray diffraction (DCXD). Hall effect on this sample was measured by the method of van der Pauw and studied on carrier density and mobility dependence on temperature. The carrier density and mobility of $CuGaTe_2$single crystal thin films deduced from Hall data are $8.72{\times}10{23}$개 $\textrm m^3$, $3.42{\times}10^{-2}$ $\textrm m^2$/V.s at 293K, respectively. From the photocurrent spectrum by illumination of perpendicular light on the c-axis of the $CuGaTe_2$single crystal thin film, we have found that the values of spin orbit coupling $\Delta$s.o and the crystal field splitting $\Delta$cr were 0.0791 eV and 0.2463 eV at 10 K, respectively. From the PL spectra at 10 K, the peaks corresponding to free bound excitons and D-A pair and a broad emission band due to SA is identified. The binding energy of the free excitons are determined to be 0.0470 eV and the dissipation energy of the donor-bound exciton and acceptor-bound exciton to be 0.0490 eV, 0.0558 eV, respectively.

• Korean journal of communication and information
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• v.22
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• pp.131-166
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• 2003

The opening of advertising market and introduction of the free competition doctrine make the competition harsher among advertising agencies. Advertising agencies do their best to execute their ad more efficiently and scientifically. But, it is the reality that broadcasting advertising industry in korea did not construct enough infrastructure to execute the systematic activities compared with that of advanced countries. So, we need to grasp the present conditions and draw a time-table to construct primarily necessary infrastructures. In case of hardware infrastructure in advertising industry, digitalization of broadcasting and convergence of broadcasting with telecommunication make it hurry to construct that. But as the ad agencies was in the situation to compete each other, they have a difficulty to construct common hardware infrastructure enthusiastically. Thus, it is necessary to build hardware infrastructure in advertising industry for policy. And the construction of that should be executed systematically not for the short term effects but for the long term objectives. Also, it is the most important to construct reliable Software infrastructure in advertising industry from all of ad agencies. In these days, ad agencies have a tendency not to believe the important information, like the data of ratings and advertising transaction information, in relation to the advertising activities. And they do not share and communicate about the information of the advertising industry trends, research trends, advertisement related information. So, it is also hurry to build the on-line and off-line database system. Finally, for the development of brainware infrastructure in advertising industry, it is the most necessary to activate the cooperation relation between university and advertising agencies. Universities need to invite experts in the advertising to teach the students practical knowledge and ad agencies to recruit students who want to develop their carrier in the advertising industries. In conclusion, advertising industry in korea to solve these tasks for the development of advertising industry infrastructure in the way of cooperation and harmony of each other rationally and efficiently.

• Korean Journal of Crystallography
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• v.7 no.1
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• pp.8-19
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• 1996

Cholestryl Methyl and Propyl Carbonate(CH3OCOOC27H45, C3H7OCOOC27H45) are monoclinic, space group P21, with a=17.014(1), b=7.682(1), c=10.612(1)Å, β=103.05(1)°, Z=2, V=1351.16Å3, Dc=1.09 g/cm3 for methyl carbonate, and with a=13.683(1), b=11.864(2), c=18.904(2)Å, β=106.30(1)°, Z=4, V=2945.4Å3, Dc=1.06 g/cm3, Dm=1.06 g/cm3 for propyl carbonate. The intensity data were collected on an Enraf-Nonius CAD-4 diffractometer with a graphite monochromated Cu-Kα radiation. The structure was solved by direct methods and refined by full matrix least-squares methods. The final R factor was 0.051 for 2323 observed reflections for methyl carbonate and 0.074 for 3323 observed reflections for propyl carbonate. Compared with other cholesteryl derivatives, the cholesteryl ring and tail region of the molecules are normal. The molecules are stacked in clearly separated layers. At center of the layer, there are cholesteryl-C(17) side chain interactions. The interface region between layers is occupied by the loosely packed methyl carbonate chains. The structure of cholesteryl propyl carbonates have two propyl carbonates have two molecules(A, B) that are not related by crystal symmetry and have their tetracyclic system almost parallel to each other. Cholesteryl-cholesteryl interactions between symmetry related A-molecules, and cholesteryl-C(17) side chain interactions between symmetry related B-molecules occur at the center of the layers and these molecules stack along 2₁ screw axes. There are also C(17)chain-carbonate chain and C(17)chain-C(17)chain interactions in the interface region between layers. There is efficient packing between cholesteryl ring systems in propyl carbonates. Temperature ranges of cholesteric mesophases of cholesteryl alkyl cargonates are narrow for methyl, pentyl and hexyl carbonates, and rather broader for ethyl and propyl carbonates. Cholesteryl-isotropic transitions change very little with chain length.

• Management & Information Systems Review
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• v.33 no.4
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• pp.1-19
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• 2014

This Study focuses on the university students' job attitude and cost of employment preparation. Nowadays, many university and college students spend a big money improving their employment preparation such as studying on foreign language, getting various kinds of certificates and tooth correction, clothing etc. for employment interview. This study investigated the cost of employment preparation and Job attitude of the 484 students of universities and colleges, the analysis of the collected data was conducted with SPSS 12.0 program by using frequency analysis, factor analysis, reliability assessment, correlation test, t-test, one way ANOVA. The university students paid more costs of employment preparation such as a language training abroad, a private training, and clothing than the college students. Also, Allied social science students paid more costs of the language training abroad, and clothing than allied computer science and allied design students. The female students paid more money than male students for tooth correction. The costs of language training abroad, private training and clothing are affected the students' socioeconomic background of a home. Regarding the job attitude of students, the university students are feeling more positive than the college students of the employment efficacy and cognition of the education environment. As result, the differences in the cost of employment preparation by the university type, faculty major course, their sex, and socioeconomic background of a home. The student's employment-efficacy and cognition of the education environment are also differences between the university and the college students. So, to improve the job attitude, developing their ability for employment preparation, educational programs should be arranged in school and continuous researches are needed.

• Tuberculosis and Respiratory Diseases
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• v.50 no.1
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• pp.76-83
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• 2001

Background : Coal workers' pneumoconiosis is a fibrotic lung disease resulting from chronic inhalation of coal dust. The precise mechanism of lung fibrosis in coal workers' pneumoconiosis is uncertain. However, a relationship between the stimulation of fibroblast proliferation and collagen production by mediators released from in flammatory and resident lung cells is thought to be a major factor. The transforming growth factor-$\beta$(TGF-$\beta$), a multifunctional cytokine and growth factor, plays a key role in the scarring and fibrotic processes due to its ability to induce extracellular matrix proteins and modulate the growth and immune function of many cell types. To determine the involvement of TGF-$\beta$ in the development of lung fibrosis in coal workers' pneumoconiosis, the TGF-${\beta}_1$ level in plasma was measured in patients with coal workers' pneumoconiosis. Methods : Plasma was collected from 40 patients with coal workers' pneumoconiosis (20 with simple coal workers' pneumoconiosis and 20 with complicated coal workers' pneumoconiosis) and from 10 normal controls. The ELISA method was used to measure the plasma TGF-${\beta}_1$ concentration. Results : Compared to the control group ($0.63{\pm}01.8$ ng/mL), there was no significant difference in the plasma TGF-${\beta}_1$ level in patients with simple coal workers' pneumoconiosis ($0.64{\pm}0.17$ ng/mL) (p>0.05). However, in patients with complicated coal workers' pneumoconiosis the plasma TGF-${\beta}_1$ level ($0.79{\pm}0.18$ ng/mL) was significantly higher than in patients with simple coal workers' pneumoconiosis and the control group (p<0.05). Conclusion : The data suggests that TGF-${\beta}_1$ has some influence in the development of lung fibrosis in coal workers' pneumoconiosis.