• Journal of Microbiology and Biotechnology
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• v.16 no.12
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• pp.1919-1927
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• 2006

Tumor cells genetically engineered to secrete cytokines are effective in tumor therapy, but various unexpected side effects are observed, which may result from the bulk activation of various bystander cells. In this study, we tested tumor vaccines expressing various membrane-bound forms of IL-2 (mbIL-2) on MethA fibrosarcoma cells to focus antitumor immune responses to CTL. Chimeric forms of IL-2 with whole CD4, deletion forms of CD4, and TNF were expressed on the tumor cell surface, respectively. Tumor clones expressing mbIL-2 or secretory form of IL-2 were able to support the cell growth of CTLL-2, an IL-2-dependent T cell line, and the proliferation of spleen cells from 2C TCR transgenic mice that are responsive to the $p2Ca/L^d$ MHC class I complex. Expression of mbIL-2 on tumor cells reduced the tumorigenicity of tumor cells, and the mice that once rejected the live IL-2/TNF tumor clone acquired systemic immunity against wild-type MethA cells. The IL-2/TNF clone was inferior to other clones in tumor formation, and superior in the stimulation of the CD8+ T cell population in vitro. These results suggest that the IL-2/TNF clone is the best tumor vaccine, and may stimulate CD8+ T cells by direct priming. Expression of IL-2/TNF on tumor cells may serve as an effective gene therapy method to ameliorate the side effects encountered in the recombinant cytokine therapy and the conventional cytokine gene therapy using the secretory form of IL-2.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.7
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• pp.555-563
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• 2020

This study aimed to distinguish between predisposing factors influencing the entrepreneurial intentions of university and college students who completed an entrepreneurship education course and to empirically determine the relationship between entrepreneurial intention and entrepreneurial behavior. Since company foundation involves uncertainty, potential entrepreneurs are known to fear creating a new company. Entrepreneurship has been confirmed in advanced studies to not only reduce this fear but also positively influence one's entrepreneurial intention. This study presents a research model that connects entrepreneurship, entrepreneurial intention, and entrepreneurial behavior and verifies it via empirical analysis. It was confirmed as a result that entrepreneurial intention is positively influenced by actively engaging with changes of a certain product or service, problem-solving capability, resolving unexpected setbacks during company foundation, and expertise in the business field where the founded company belongs to. It was also confirmed that entrepreneurial intention has a positive influence on entrepreneurial behavior. In the conclusion of this study, importance and necessity of entrepreneurship education are discussed in order to essentially improve entrepreneurial intention and company foundation via entrepreneurship education.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.8
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• pp.572-578
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• 2020

The stock market is affected by unexpected factors, such as politics, society, and natural disasters, as well as by corporate performance and economic conditions. In recent days, artificial intelligence has become popular, and many researchers have tried to conduct experiments with that. Our study proposes an experiment using not only stock-related data but also other various economic data. We acquired a year's worth of data on stock prices, the percentage of foreigners, interest rates, and exchange rates, and combined them in various ways. Thus, our input data became diversified, and we put the combined input data into a nonlinear autoregressive network with exogenous inputs (NARX) model. With the input data in the NARX model, we analyze and compare them to the original data. As a result, the model exhibits a root mean square error (RMSE) of 0.08 as being the most accurate when we set 10 neurons and two delays with a combination of stock prices and exchange rates from the U.S., China, Europe, and Japan. This study is meaningful in that the exchange rate has the greatest influence on stock prices, lowering the error from RMSE 0.589 when only closing data are used.

• Korean Chemical Engineering Research
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• v.58 no.4
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• pp.604-609
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• 2020

The purpose of this study is to check the priority control status of the current operation process alarm by comparing the priority of the alarm set up in PV high trip point, which is being installed and operated in the domestic petrochemical industry, with the criteria presented in ISA 18.2 International Standard or EEMUA 191 Guidelines. In the event of a process problem, excessively set high alarm is provided to the driver in a short period of time, making it difficult to identify the alarm that needs to be handled first. As a result, it is likely that the operator will not be able to carry out appropriate actions within the specified time frame, and many cases have been reported leading to unexpected process shutdowns or process accidents. Therefore, this study aims to introduce international standards related to alarm management and identify the level of alarm control used at the domestic petrochemical industry site to inform potential risks that may occur in the petrochemical process of the national industrial complex in the future and suggest ways to reduce risk factors. This paper was submitted to Professor Lee Inbeom's retirement anniversary issue.

• The KIPS Transactions:PartA
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• v.18A no.3
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• pp.109-114
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• 2011

We describe a technique for automatically proving compiler optimizations sound, meaning that their transformations are always semantics-preserving. As is well known, IR (Intermediate Representation) optimization is an important step in a compiler backend. But unfortunately, it is difficult to detect and debug the IR optimization errors for compiler developers. So, we introduce a C level error check system for detecting the correctness of these IR transformation techniques. In our system, we first create an IR-to-C converter to translate IR to C code before and after each compiler optimization phase, respectively, since our technique is based on the Memory Comparison-based Clone(MeCC) detector which is a tool of detecting semantic equivalency in C level. MeCC accepts only C codes as its input and it uses a path-sensitive semantic-based static analyzer to estimate the memory states at exit point of each procedure, and compares memory states to determine whether the procedures are equal or not. But MeCC cannot guarantee two semantic-equivalency codes always have 100% similarity or two codes with different semantics does not get the result of 100% similarity. To increase the reliability of the results, we describe a technique which comprises how to generate C codes in IR-to-C transformation phase and how to send the optimization information to MeCC to avoid the occurrence of these unexpected problems. Our methodology is illustrated by three familiar optimizations, dead code elimination, instruction scheduling and common sub-expression elimination and our experimental results show that the C level error check system is highly reliable.

• The Journal of the Acoustical Society of Korea
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• v.22 no.7
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• pp.519-527
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• 2003

Speech is much influenced by the existence of outliers which are introduced by such an unexpected happenings as additive background noise, change of speaker's utterance pattern and voice detection errors. These kinds of outliers may result in severe degradation of speaker recognition performance. In this paper, we proposed the GMM based on robust principal component analysis (RPCA-GMM) using M-estimation to solve the problems of both ouliers and high dimensionality of training feature vectors in speaker identification. Firstly, a new feature vector with reduced dimension is obtained by robust PCA obtained from M-estimation. The robust PCA transforms the original dimensional feature vector onto the reduced dimensional linear subspace that is spanned by the leading eigenvectors of the covariance matrix of feature vector. Secondly, the GMM with diagonal covariance matrix is obtained from these transformed feature vectors. We peformed speaker identification experiments to show the effectiveness of the proposed method. We compared the proposed method (RPCA-GMM) with transformed feature vectors to the PCA and the conventional GMM with diagonal matrix. Whenever the portion of outliers increases by every 2%, the proposed method maintains almost same speaker identification rate with 0.03% of little degradation, while the conventional GMM and the PCA shows much degradation of that by 0.65% and 0.55%, respectively This means that our method is more robust to the existence of outlier.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.46 no.1
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• pp.10-21
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• 2009

In order to enhance the contrast in the regions where the pixels have similar intensities, this paper presents a new histogram equalization scheme. Conventional global equalization schemes over-equalizes those regions so that too bright or dark pixels are resulted and local equalization schemes produce unexpected discontinuities at the boundaries of the blocks. The proposed algorithm segments the original histogram into sub-histograms with reference to brightness level and equalizes each sub-histogram with the limited extents of equalization considering its mean and variance. The final image is determined as the weighted sum of the equalized images obtained by using the sub-histogram equalizations. By limiting the maximum and minimum ranges of equalization operations on individual sub-histograms, the over-equalization effect is eliminated. Also the result image does not miss feature information in low density histogram region since the remaining these area is applied separating equalization. This paper includes how to determine the segmentation points in the histogram. The proposed algorithm has been tested with more than 100 images having various contrast in the images and the results are compared to the conventional approaches to show its superiority.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.47 no.4
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• pp.1-10
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• 2010

This present paper's goal is to show a virtual human agent's movement-data loci based on realistically limited perception data is human-like. To determine human-likeness of the movement-data loci, we consider interactions between two parameters: Realistically Limited Perception (RLP) data and Incremental Movement-Path data Generation (IMPG). That is to consider how the former (i.e., RLP), one of the simulated parameters of human thought or its elements dictates the latter (i.e., IMPG), one of the simulated parameters of human movement behavior. Mapping DB is a prerequisite for navigation in an agent system because it functions as an interface between perception and movement behavior. Although Hill et al. studied mapping DB methodology based on RLP, their research dealt only with a rendering camera's view point data. The agent system in this present paper was integrated with the Hill's mapping DB module and then the two parameters' interaction was considered on a military reconnaissance mission with unexpected enemy emergence. Movement loci that were generated by the agent and subjects were compared with each other. The agent system in this present research verifies that it can be a functional test bed for producing human-like movement-data loci although the human-likeness of agent is the result of a pilot test, determined by two parameters (RLP and IMPG) and only 30 subjects.

• 한국HCI학회:학술대회논문집
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• 2007.02a
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• pp.243-249
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• 2007

In this paper we introduce a system that assists news reporters to easily edit source video anywhere, and transfer the result from a remote site to the station. Presently reporters are bothered to edit source materials, compress and transfer using several separate tools. Moreover such tools have lots of too complicated features to use only for news production. We have integrated file sending and video editing functions together for seamless workflow. News programs usually need promptness in production. For this reason our system is designed to make it possible the one-stop production of news items outside the TV station. Also the system reflects the demands of field workers, that is, easy usage for the beginner and features for speedy news production. One of the most focused is that the reliability of the system is guaranteed in the process of transfer. To achieve this end, we have implemented several error-resilient schemes for unexpected network errors. Our system consists of remote laptop editing terminals and a newsgathering server. DV-format based editing and analog-to-DV converting device are adopted to capture video from not only lightweight DV camcorders but also old-fashioned ENG cameras into laptop computers. We expect that news reporters and cameramen can take terminals anywhere the Internet is available and both editing and sending will be done on the spot. This will help increase the competitive power of our news production.

• The Journal of Korean society of community based occupational therapy
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• v.1 no.1
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• pp.7-17
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• 2011

Objective : This study aimed to understand the experience of taking a bus, investigate successful strategies to overcome the psychological difficulties of people with disabilities. Method : In this study, a phenomenological and hermeneutic approach was used to gain a deeper understanding of the behavior, the language, the process. For participants through interviews and participant observation data were collected. Phenomenological interpretation of the way through technology and to evaluate the results. Result : Ambulatory persons with disabilities in the community have confidence in the bus-independent movement in the community possible. And get on and off the bus at the moment of urgent strategies to use in the bus seats were taken. To cope with unexpected situations like that do not put stress was confirmed. In addition, by bus and go sit on the seat to look at the patient's burden was to. Conclusion : Ambulant disabled people's confidence in the bus had a significant impact on the independent movement. Always on the lookout for falling, and many psychological difficulties and to overcome unforeseen circumstances to predict and know that public transportation could be.