• Title/Summary/Keyword: dependent error

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Why A Multimedia Approach to English Education\ulcorner

  • Keem, Sung-uk
    • Proceedings of the KSPS conference
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    • 1997.07a
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    • pp.176-178
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    • 1997
  • To make a long story short I made up my mind to experiment with a multimedia approach to my classroom presentations two years ago because my ways of giving instructions bored the pants off me as well as my students. My favorite ways used to be sometimes referred to as classical or traditional ones, heavily dependent on the three elements: teacher's mouth, books, and chalk. Some call it the 'MBC method'. To top it off, I tried audio-visuals such as tape recorders, cassette players, VTR, pictures, and you name it, that could help improve my teaching method. And yet I have been unhappy about the results by a trial and error approach. I was determined to look for a better way that would ensure my satisfaction in the first place. What really turned me on was a multimedia CD ROM title, ELLIS (English Language Learning Instructional Systems) developed by Dr. Frank Otto. This is an integrated system of learning English based on advanced computer technology. Inspired by the utility and potential of such a multimedia system for regular classroom or lab instructions, I designed a simple but practical multimedia language learning laboratory in 1994 for the first time in Korea(perhaps for the first time in the world). It was high time that the conventional type of language laboratory(audio-passive) at Hahnnam be replaced because of wear and tear. Prior to this development, in 1991, I put a first CALL(Computer Assisted Language Learning) laboratory equipped with 35 personal computers(286), where students were encouraged to practise English typing, word processing and study English grammar, English vocabulary, and English composition. The first multimedia language learning laboratory was composed of 1) a multimedia personal computer(486DX2 then, now 586), 2) VGA multipliers that enable simultaneous viewing of the screen at control of the instructor, 3) an amplifIer, 4) loud speakers, 5)student monitors, 6) student tables to seat three students(a monitor for two students is more realistic, though), 7) student chairs, 8) an instructor table, and 9) cables. It was augmented later with an Internet hookup. The beauty of this type of multimedia language learning laboratory is the economy of furnishing and maintaining it. There is no need of darkening the facilities, which is a must when an LCD/beam projector is preferred in the laboratory. It is headset free, which proved to make students exasperated when worn more than- twenty minutes. In the previous semester I taught three different subjects: Freshman English Lab, English Phonetics, and Listening Comprehension Intermediate. I used CD ROM titles like ELLIS, Master Pronunciation, English Tripple Play Plus, English Arcade, Living Books, Q-Steps, English Discoveries, Compton's Encyclopedia. On the other hand, I managed to put all teaching materials into PowerPoint, where letters, photo, graphic, animation, audio, and video files are orderly stored in terms of slides. It takes time for me to prepare my teaching materials via PowerPoint, but it is a wonderful tool for the sake of presentations. And it is worth trying as long as I can entertain my students in such a way. Once everything is put into the computer, I feel relaxed and a bit excited watching my students enjoy my presentations. It appears to be great fun for students because they have never experienced this type of instruction. This is how I freed myself from having to manipulate a cassette tape player, VTR, and write on the board. The student monitors in front of them seem to help them concentrate on what they see, combined with what they hear. All I have to do is to simply click a mouse to give presentations and explanations, when necessary. I use a remote mouse, which prevents me from sitting at the instructor table. Instead, I can walk around in the room and enjoy freer interactions with students. Using this instrument, I can also have my students participate in the presentation. In particular, I invite my students to manipulate the computer using the remote mouse from the student's seat not from the instructor's seat. Every student appears to be fascinated with my multimedia approach to English teaching because of its unique nature as a new teaching tool as we face the 21st century. They all agree that the multimedia way is an interesting and fascinating way of learning to satisfy their needs. Above all, it helps lighten their drudgery in the classroom. They feel other subjects taught by other teachers should be treated in the same fashion. A multimedia approach to education is impossible without the advent of hi-tech computers, of which multi functions are integrated into a unified system, i.e., a personal computer. If you have computer-phobia, make quick friends with it; the sooner, the better. It can be a wonderful assistant to you. It is the Internet that I pay close attention to in conjunction with the multimedia approach to English education. Via e-mail system, I encourage my students to write to me in English. I encourage them to enjoy chatting with people all over the world. I also encourage them to visit the sites where they offer study courses in English conversation, vocabulary, idiomatic expressions, reading, and writing. I help them search any subject they want to via World Wide Web. Some day in the near future it will be the hub of learning for everybody. It will eventually free students from books, teachers, libraries, classrooms, and boredom. I will keep exploring better ways to give satisfying instructions to my students who deserve my entertainment.

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Enhancement of the solubility of human tissue inhibitor of matrix metallocroteinase-2 (TIMP-2) in E. coli using a modified in vitro mutagenesis (새로운 유전자 재조합 방법을 이용한 대장균에서의 인간 tissue inhibitor of mtrix metalloproteinase-2 (TIMP-2) 유전자의 가용성 발현)

  • Kim, Jong-Uk;Choi, Dong-Soon;Joo, Hyun;Min, Churl-K.
    • KSBB Journal
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    • v.23 no.3
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    • pp.231-238
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    • 2008
  • The second family member of tissue inhibitors of matrix metalloproteinases, TIMP-2, is a 21kDa protein which inhibits matrix metalloproteinases 2 (MMP-2). Expression of mammalian proteins in E. coli often forms inclusion bodies that are made up of mis-folded or insoluble protein aggregates. The requirement for the formation of 6 disulfide bonds in the process of the TIMP-2 folding is likely to be incompatible with the reducing environment of E. coli. However, this incompatibility can be often overcome by introducing a mutagenesis that could lead to enhancement of the protein solubility. In this reason, we have attempted to express the soluble TIMP-2 in E. coli by applying a modified staggered extension process (StEP), one of the in vitro PCR-based recombinant mutagenesis methods, and error-prone PCR. C-terminally located CAT fusion protein with respect to mutated TIMP-2 proteins enables us to differentiate the soluble TIMP-2 from the insoluble in E. coli by virtue of chloramphenicol resistance. According to this scheme, E. coli harboring properly-folded CAT fused to TIMP-2 protein was selected, and some of the resulting colonies exhibited an enhanced, soluble expression of TIMP-2 compared to the wild type, implying (i) the StEP technique is successfully employed to enhance the proper folding thereby increasing the solubility of TIMP-2, and (ii) the CAT dependent screening may be a simple and effective method to differentiate the soluble protein expression in E. coli.

A Study on eDesign Platform for Effective Communication and Information sharing - with an emphasis on process and template (효과적인 커뮤니케이션과 정보공유를 위한 e디자인 플랫폼 구축에 관한 연구 - 프로세스와 템플릿을 중심으로)

  • 윤주현
    • Archives of design research
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    • v.17 no.2
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    • pp.425-436
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    • 2004
  • A new design field called eDesign appears as if eBiz is an online related business in which an industrialized design creates the individual value added facing a digital revolution. The field of eDesign requires a special design process and management methodology regardless of the fact that human sensitivity will be satisfied through a dehumanized computer technique. However, it is the reality of eDesign that has been dependent upon a simple process or project management tool of general design. In this study, we develop an eDesign platform based on an eDesign process and template mainly focused on eBusiness in order to overcome the wrong situation. The template is a kind of document that has a standardization form. We aim to establish a general process through various case projects, store information using a necessary template, and use for the way of visual communication. We propose a standard of eDesign platform that can be widely applied to the field of design, medium and small enterprises focused on IT businesses or design-team through this project performed as an educational-industrial study. It makes it possible to get a detailed process methodology, which can be applied to many small design related companies that don't have their own process yet, and will be a scale for comparing their own process in which the company has a process of opened standard eDesign with it. In addition, it makes possible a systematic control of the own projects within and outside the firm, accumulating information for the firm through the database, and easy communication. Furthermore, it can be applied to check the process of the project as a checklist, and then it will reduce trial and error repeated for every project that has been done.

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A Study on Retrieval of Storage Heat Flux in Urban Area (우리나라 도심지에서의 저장열 산출에 관한 연구)

  • Lee, Darae;Kim, Honghee;Lee, Sang-Hyun;Lee, Doo-Il;Hong, Jinkyu;Hong, Je-Woo;Lee, Keunmin;Lee, Kyeong-sang;Seo, Minji;Han, Kyung-Soo
    • Korean Journal of Remote Sensing
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    • v.34 no.2_1
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    • pp.301-306
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    • 2018
  • Urbanization causes urban floods and urban heat island in the summer, so it is necessary to understanding the changes of the thermal environment through urban climate and energy balance. This can be explained by the energy balance, but in urban areas, unlike the typical energy balance, the storage heat flux saved in the building or artificial land cover should be considered. Since the environment of each city is different, there is a difficulty in applying the method of retrieving the storage heat flux of the previous research. Especially, most of the previous studies are focused on the overseas cities, so it is necessary to study the storage heat retrieval suitable for various land cover and building characteristics of the urban areas in Korea. Therefore, the object of this study, it is to derive the regression formula which can quantitatively retrieve the storage heat using the data of the area where various surface types exist. To this end, nonlinear regression analysis was performed using net radiation and surface temperature data as independent variables and flux tower based storage heat estimates as dependent variables. The retrieved regression coefficients were applied to each independent variable to derive the storage heat retrieval regression formula. As a result of time series analysis with flux tower based storage heat estimates, it was well simulated high peak at day time and the value at night. Moreover storage heat retrieved in this study was possible continuous retrieval than flux tower based storage heat estimates. As a result of scatter plot analysis, accuracy of retrieved storage heat was found to be significant at $50.14Wm^{-2}$ and bias $-0.94Wm^{-2}$.

Middle School Students' Construction of Physics Inquiry Problems and Variables Isolation and Clarification during Small Group Open-inquiry Activities (중학생의 소집단 자유탐구활동 중 물리 영역 탐구문제의 구성과 변인 추출 및 명료화 과정)

  • Yoo, Junehee;Kim, Jongsook
    • Journal of The Korean Association For Science Education
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    • v.32 no.5
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    • pp.903-927
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    • 2012
  • The study aimed to analyze middle school students construction of physics inquiry problems for open inquiry from the viewpoint of variable isolation and clarification, and investigate students' difficulties during the processes of variable isolation and clarification to get implications for teaching and learning strategies for small group open inquiry activities which have been included in the 2007 national curriculum. The participants were 4 students who had attended an outreach program for the science gifted run by a university institution located in Seoul area. They performed an open inquiry on egg drop for 13 lessons for 30 hours. Level descriptions for variable isolation and clarification have been developed and applied to analyze students' inquiry problems and variables included by the problems. Students iterated inquiry processed 5 times and the inquiry problem showed progress gradually. Dependent variables have been isolated ahead and the levels of variable isolation and clarification showed higher than the independent variables. Many kinds of independent variables isolated extensively and the independent variables and control variables have been mingled. One of the reasons why students had some difficulties in isolation of independent variables could be the absence of theoretical models. The realities of school lab could restrict the variable isolation and clarification as well as topic selections. Some sensory or extensive variables such as broken eggs and drop height seem to be salient to be focused on as core variables. Lack of background knowledges could be one of the reasons for students' difficulties in variable clarification, such as theoretical definitions and operational definitions. As a result of lacking background knowledges, students could not construct theoretical models even though they could isolate and clarify variables as scientific lexical definitions. Some perceptions of inquiry as trial and error or reckless establishment of causal relations between variables could be accounted as one reason.

The Study of DNA Mutations of Phenylketonuria in Koreans (한국인에서의 페닐케톤뇨증의 유전자변이에 대한 고찰)

  • Yoo, Su-Jung;Hong, Yong-Hee;Lee, Yong-Wha;Jung, Sung-Chul;Ki, Chang-Seok;Lee, Dong-Hwan
    • Journal of Genetic Medicine
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    • v.5 no.1
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    • pp.26-33
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    • 2008
  • Purpose : Phenylketonuria(PKU) is an inborn error of metabolism and a genetic disorder resulting from a deficiency of phenylalanine hydroxylase(PAH) and decreased activity of tetrahydrobiopterin(BH4).In this study the correlation between the DNA mutation and clinical manifestations was investigated and PAH DNA mutations were compared bewteen Asian and Caucasian populations. Methods : DNA was isolated from peripheral leukocytes. The PAH gene was amplified by Polymerase Chain Reaction(PCR) and the sequence was analyzed with Multiplex Ligation-dependent Probe Amplification(MLPA). Results : We characterized the PAH gene of 102 independent Korean patients with PKU. PAH nucleotide sequence analysis revealed 44 different mutations, including 10 novel mutations comprising 9 missense mutations(N207D, K95del, A447P, G344D, P69S, S391I, A202T, G103S, and I306L) and 1 novel splice-site variant mutation(IVS10-3C>G). R243Q was the most prevalent mutation in this study. A259T has not previously been reported in Asian populations, but we found that this mutation had a frequency of 10.1% in our study. Furthermore, the genotypes of $BH_4$ responsive patients were analyzed and were divided into two groups: $BH_4$ medication-only group and $BH_4$ medication with diet therapy group. In the $BH_4$ medication-only group and $BH_4$ medication with diet therapy group, R241C was the most common mutation. Conclusion : Novel mutations in the PAH gene of PKU patients are still being discovered. Additional information as to the frequency of mutations in the tetrahydrobiopterine responsive gene is also accumulating. We anticipate that knowledge of these PKU gene mutations will assist the diagnosis, genetic counseling, and therapeutic treatment of PKU patients in future.

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PCA­based Waveform Classification of Rabbit Retinal Ganglion Cell Activity (주성분분석을 이용한 토끼 망막 신경절세포의 활동전위 파형 분류)

  • 진계환;조현숙;이태수;구용숙
    • Progress in Medical Physics
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    • v.14 no.4
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    • pp.211-217
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    • 2003
  • The Principal component analysis (PCA) is a well-known data analysis method that is useful in linear feature extraction and data compression. The PCA is a linear transformation that applies an orthogonal rotation to the original data, so as to maximize the retained variance. PCA is a classical technique for obtaining an optimal overall mapping of linearly dependent patterns of correlation between variables (e.g. neurons). PCA provides, in the mean-squared error sense, an optimal linear mapping of the signals which are spread across a group of variables. These signals are concentrated into the first few components, while the noise, i.e. variance which is uncorrelated across variables, is sequestered in the remaining components. PCA has been used extensively to resolve temporal patterns in neurophysiological recordings. Because the retinal signal is stochastic process, PCA can be used to identify the retinal spikes. With excised rabbit eye, retina was isolated. A piece of retina was attached with the ganglion cell side to the surface of the microelectrode array (MEA). The MEA consisted of glass plate with 60 substrate integrated and insulated golden connection lanes terminating in an 8${\times}$8 array (spacing 200 $\mu$m, electrode diameter 30 $\mu$m) in the center of the plate. The MEA 60 system was used for the recording of retinal ganglion cell activity. The action potentials of each channel were sorted by off­line analysis tool. Spikes were detected with a threshold criterion and sorted according to their principal component composition. The first (PC1) and second principal component values (PC2) were calculated using all the waveforms of the each channel and all n time points in the waveform, where several clusters could be separated clearly in two dimension. We verified that PCA-based waveform detection was effective as an initial approach for spike sorting method.

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Agroclimatology of North Korea for Paddy Rice Cultivation: Preliminary Results from a Simulation Experiment (생육모의에 의한 북한지방 시ㆍ군별 벼 재배기후 예비분석)

  • Yun Jin-Il;Lee Kwang-Hoe
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.2 no.2
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    • pp.47-61
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    • 2000
  • Agroclimatic zoning was done for paddy rice culture in North Korea based on a simulation experiment. Daily weather data for the experiment were generated by 3 steps consisting of spatial interpolation based on topoclimatological relationships, zonal summarization of grid cell values, and conversion of monthly climate data to daily weather data. Regression models for monthly climatological temperature estimation were derived from a statistical procedure using monthly averages of 51 standard weather stations in South and North Korea (1981-1994) and their spatial variables such as latitude, altitude, distance from the coast, sloping angle, and aspect-dependent field of view (openness). Selected models (0.4 to 1.6$^{\circ}C$ RMSE) were applied to the generation of monthly temperature surface over the entire North Korean territory on 1 km$\times$l km grid spacing. Monthly precipitation data were prepared by a procedure described in Yun (2000). Solar radiation data for 27 North Korean stations were reproduced by applying a relationship found in South Korea ([Solar Radiation, MJ m$^{-2}$ day$^{-1}$ ] =0.344 + 0.4756 [Extraterrestrial Solar Irradiance) + 0.0299 [Openness toward south, 0 - 255) - 1.307 [Cloud amount, 0 - 10) - 0.01 [Relative humidity, %), $r^2$=0.92, RMSE = 0.95 ). Monthly solar irradiance data of 27 points calculated from the reproduced data set were converted to 1 km$\times$1 km grid data by inverse distance weighted interpolation. The grid cell values of monthly temperature, solar radiation, and precipitation were summed up to represent corresponding county, which will serve as a land unit for the growth simulation. Finally, we randomly generated daily maximum and minimum temperature, solar irradiance and precipitation data for 30 years from the monthly climatic data for each county based on a statistical method suggested by Pickering et a1. (1994). CERES-rice, a rice growth simulation model, was tuned to accommodate agronomic characteristics of major North Korean cultivars based on observed phenological and yield data at two sites in South Korea during 1995~1998. Daily weather data were fed into the model to simulate the crop status at 183 counties in North Korea for 30 years. Results were analyzed with respect to spatial and temporal variation in yield and maturity, and used to score the suitability of the county for paddy rice culture.

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Developing a Traffic Accident Prediction Model for Freeways (고속도로 본선에서의 교통사고 예측모형 개발)

  • Mun, Sung-Ra;Lee, Young-Ihn;Lee, Soo-Beom
    • Journal of Korean Society of Transportation
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    • v.30 no.2
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    • pp.101-116
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    • 2012
  • Accident prediction models have been utilized to predict accident possibilities in existing or projected freeways and to evaluate programs or policies for improving safety. In this study, a traffic accident prediction model for freeways was developed for the above purposes. When selecting variables for the model, the highest priority was on the ease of both collecting data and applying them into the model. The dependent variable was set as the number of total accidents and the number of accidents including casualties in the unit of IC(or JCT). As a result, two models were developed; the overall accident model and the casualty-related accident model. The error structure adjusted to each model was the negative binomial distribution and the Poisson distribution, respectively. Among the two models, a more appropriate model was selected by statistical estimation. Major nine national freeways were selected and five-year dada of 2003~2007 were utilized. Explanatory variables should take on either a predictable value such as traffic volumes or a fixed value with respect to geometric conditions. As a result of the Maximum Likelihood estimation, significant variables of the overall accident model were found to be the link length between ICs(or JCTs), the daily volumes(AADT), and the ratio of bus volume to the number of curved segments between ICs(or JCTs). For the casualty-related accident model, the link length between ICs(or JCTs), the daily volumes(AADT), and the ratio of bus volumes had a significant impact on the accident. The likelihood ratio test was conducted to verify the spatial and temporal transferability for estimated parameters of each model. It was found that the overall accident model could be transferred only to the road with four or more than six lanes. On the other hand, the casualty-related accident model was transferrable to every road and every time period. In conclusion, the model developed in this study was able to be extended to various applications to establish future plans and evaluate policies.

Estimation of Reference Crop Evapotranspiration Using Backpropagation Neural Network Model (역전파 신경망 모델을 이용한 기준 작물 증발산량 산정)

  • Kim, Minyoung;Choi, Yonghun;O'Shaughnessy, Susan;Colaizzi, Paul;Kim, Youngjin;Jeon, Jonggil;Lee, Sangbong
    • Journal of The Korean Society of Agricultural Engineers
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    • v.61 no.6
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    • pp.111-121
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    • 2019
  • Evapotranspiration (ET) of vegetation is one of the major components of the hydrologic cycle, and its accurate estimation is important for hydrologic water balance, irrigation management, crop yield simulation, and water resources planning and management. For agricultural crops, ET is often calculated in terms of a short or tall crop reference, such as well-watered, clipped grass (reference crop evapotranspiration, $ET_o$). The Penman-Monteith equation recommended by FAO (FAO 56-PM) has been accepted by researchers and practitioners, as the sole $ET_o$ method. However, its accuracy is contingent on high quality measurements of four meteorological variables, and its use has been limited by incomplete and/or inaccurate input data. Therefore, this study evaluated the applicability of Backpropagation Neural Network (BPNN) model for estimating $ET_o$ from less meteorological data than required by the FAO 56-PM. A total of six meteorological inputs, minimum temperature, average temperature, maximum temperature, relative humidity, wind speed and solar radiation, were divided into a series of input groups (a combination of one, two, three, four, five and six variables) and each combination of different meteorological dataset was evaluated for its level of accuracy in estimating $ET_o$. The overall findings of this study indicated that $ET_o$ could be reasonably estimated using less than all six meteorological data using BPNN. In addition, it was shown that the proper choice of neural network architecture could not only minimize the computational error, but also maximize the relationship between dependent and independent variables. The findings of this study would be of use in instances where data availability and/or accuracy are limited.