• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.4
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• pp.773-778
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• 2020

In this paper, we analyzed the effects of musical stimuli on humans in performing mathematical tasks through EEG measurements. The musical stimuli were divided into preferred music and non-preferred music, and mathematical tasks were divided into memorization task and procedure task. The data measured in the EEG experiments was divided into frequency bands of Theta, SMR, and Mid-beta because of the concentration. In our results, preferred music causes more positive emotional response than no music and non-preferred music regardless of the type of mathematical task.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.3
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• pp.565-570
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• 2016

User requirements for access and authentication increase daily because of the diversification of the Internet of Things (IoT) and social structures. The increase in authentication needs requires the generation of new passwords. Users want to utilize the same passwords for memorization convenience. However, system administrators request each user to use different passwords, as well as passwords that include special symbols. Differnet passwords and including special symbols passwords seem to exceed the tolerance range within your memorization skills. It fetches a very negative consequences in terms of password management. This paper proposes a preference symbol password system that does not require memorization by users. First, a survey is conducted to prove statistical safety, and based on this, an evolution-type password system that uses preference symbols is designed. Preference symbol passwords show superiority with respect to installation cost and convenience, compared with conventional non-memorizing password systems such as biometrics, keystrokes, and mouse patterns.

• Horticultural Science & Technology
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• v.34 no.1
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• pp.67-76
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• 2016

This study was conducted to examine the optimal environmental condition for promoting the growth of sowthistle as affected by light quality and photoperiod in a closed-type plant production system. Seeds were sown in 240-cell plug trays and then germinated for 3 days at a 24-hour photoperiod in a closed-type plant production system with LED lights (R:B:W = 8:1:1). Seedlings were transplanted and grown under 3 types of LED (R:B:W = 8:1:1, R:W = 3:7, or R:B = 8:2) and 4 photoperiods (24/0, 16/8, 8/16, or 4/20 hours) with $230{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ light intensity at a density of $20cm{\times}20 cm$. The experimental design was a randomized complete block design. Plants were cultured for 40 days un der the condition of $21{\pm}2^{\circ}C$ and $70{\pm}10%$ relative humidity after transplanting. Plants were fed with a recycling nutrient solution (pH 7.0 and EC $2.0dS{\cdot}m^{-1}$) contained in a deep floating tank. Fresh weight and dry weight of shoot or root, leaf length, and leaf area were the greatest in the photoperiod of 24/0 (light/dark) with RW LED. The highest number of leaves occurred in the photoperiod of 16/8 (light/dark) with RB LED, while the incidence of tip burn was higher in the photoperiod of 24/0 (light/dark) compared to the other treatments. Chlorophyll value was the highest in the 16/8 (light/dark) photoperiod and there was no significant difference by light quality. Chlorophyll fluorescence was the lowest in the photoperiod of 24/0 (light/dark) compared with other treatments. Therefore, in terms of economic feasibility and productivity for Ixeris dentata Nakai cultivation in a closed-type plant production system, the results obtained suggest that plants grew the best when kept in a photoperiod of 16/8 (light/dark) and light quality of combined LED RW (3:7).

• Horticultural Science & Technology
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• v.30 no.6
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• pp.673-679
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• 2012

This study was conducted to examine the effect of artificial light source and photoperiod on the growth of leaf lettuce (Lactuca sativa L.) 'Seonhong Jeokchukmyeon' in a closed-type plant production system. Seedlings were grown under 3 light sources, fluorescent lamp (FL, Philips Co. Ltd., the Netherlands), WL #1 (Hepas Co. Ltd., Korea), and WL #2 (FC Poibe Co., Ltd., Korea), each with 3 photoperiods, 12/12, 18/6, and 24/0 (Light/Dark). An irradiance spectrum analysis showed that FL has various peaks in the 400-700 nm range, while WL #1 and WL #2 have only one monochromatic peak at 450 and 550 nm, respectively. The greatest plant height, fresh and dry weights were obtained in the 24/0 (Light/Dark) photoperiod. The 24/0 (Light/Dark) photoperiod treatment promoted vegetative growth of the leaf area. Length of the longest root, number of leaves, fresh weight, and total anthocyanin contents were greater in FL than in either WL #1 or #2. The greatest chlorophyll fluorescence (Fv/Fm) was found in the 12/12 (Light/Dark) photoperiod with FL treatment. The energy use efficiency of the LED increased by about 35-46% as compared to FL. Results suggest a possibility of LED being used as a substitute light source for fluorescent lamp for lettuce cultivation in a plant factory system.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.3
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• pp.505-510
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• 1997

Temperature and light responses on the growth and maturation of gametophytes of Undaria pinnatifida were studied in laboratory culture. The effect of the environmental factors on formation of young sporophyte of U. pinnatifida was also examined in the same culture system. Maximum growth and rapid maturation of the gametophytes were observed at $12:12LD,\;17^{\circ}C$ and 60{\mu}mol\;m^{-2}s^{-1}. However, they survived in a wide range of the examined temperature, light intensity and photoperiod. Particularly they survived under continuous dark condition (0:24LD) until 210 days without any growth and maturation, but died within $10\~40$ days at $30^{\circ}C$. This suggests that optimum rendition for conservation of Undaria gametophytes is under continuous dark photoperiod at $17\~25^{\circ}C$.

• Journal of Bio-Environment Control
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• v.22 no.3
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• pp.228-233
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• 2013

This study was conducted to examine the effect of light intensity and photoperiod of white LEDs as the artificial light source on the growth of leaf lettuce (Lactuca sativa L.) 'Seonhong Jeokchukmyeon' in a closed-type plant production system. Seedlings, transplanted at a density of $20cm{\times}20cm$ in a completely randomized design, were grown under white LEDs (FC Poibe Co. Ltd., Korea), at one of the 3 light intensities (100, 200, or $300{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$), and each with one of 3 photoperiods [12/12, 18/6, or 24/0 (Light/Dark)]. Plants were cultured for 22 days under the condition of $21{\pm}2^{\circ}C$, $60{\pm}10%$ RH, and $400{\pm}50{\mu}mol{\cdot}mol^{-1}\;CO_2$. The greatest leaf length and width, fresh and dry weights, and total anthocyanin content were obtained in the 24/0 photoperiod, regardless of the light intensity. Length of the longest root, fresh and dry weights, and number of leaves were greater in light intensity of $200{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ than 100 or $300{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$. Chlorophyll value was the greatest in the photoperiod 12/12 than 18/6 or 24/0. The results obtained suggest that plant grew the best kept by light intensity at 200 or $300{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, and photoperiod of 12/12 or 18/6.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.1
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• pp.89-94
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• 2021

In this paper, we presented the results of analysis with data obtained through EEG measurements to confirm the effect of musical stimulus when performing mathematical tasks. While the subject was solving a mathematical task, favorite and unfavorite music classified according to the subject's preference were presented as musical stimulus and the tasks were divided into memorization task and procedure task. The data measured in the EEG experiments was divided into theta waves, SMR waves and mid-beta waves which are the frequency bands related to concentration to compare the relative power spectrum values. In our results, in the case of comparing no music with favorite music and no music with unfavorite music, a significant difference was observed in the several channels, and the average difference was shown in the channels F3 and F4 of the frontal lobe. In that channels, the power was found to be greater when the music was presented than the case where there was no music. Depending on the subject's preference, it was confirmed that favorite music showed greater brain activity than unfavorite music.

• Annual Conference on Human and Language Technology
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• 2001.10d
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• pp.267-272
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• 2001

구(phrase) 단위 또는 문장(sentence) 단위의 연어(collocation) 정보는 자연언어 처리를 위한 단일어 또는 이중어 데이터베이스를 구축할 수 있는 중요한 기초 자료가 될 뿐 아니라, 외국어 학습에서도 어휘 단계를 넘어선 학습 자료를 제공할 수 있다. 불어는 굴절 언어(inflectional language)로서 기본형 대 굴절형의 비율이 약 1:9 정도로 비교적 굴절 비율이 높은 언어다. 또한 불어 표제어 중 95% 이상을 차지하는 불어의 동사, 명사, 형용사 중 상당한 비율이 암기해야 할 목록(list)이라는 특성을 갖기 때문에 검색과 학습에 있어 오류가 지속적으로 일어나는 부분이다. 표제어의 검색의 경우 불어 굴절 현상을 지원하는 전자 사전이 개발되어 있지만 아직까지 연어 정보에서 굴절형을 지원할 수 사전 또는 데이터베이스는 개발되어 있지 않다. 본 연구의 목적은 전자 사전과 형태소 분석기를 이용하여 굴절형 처리를 지원할 수 있는 불-한 연어 데이터베이스를 구축하는데 있다. 이를 위해 부산대학교 언어정보 연구실에서 개발한 불어 형태소 분석기 Infection와 불-한 전자 사전 Franco를 사용하였으며, 지금까지 구축된 불-한 연어 정보는 94,965 개이다. 본 고에서는 두 정보를 이용하여 불어 굴절형 정보를 분석 및 생성하는 방식 및 불-한 연어 데이터베이스 구조를 살펴 본다.

• Proceedings of the Korea Information Processing Society Conference
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• 2022.11a
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• pp.88-90
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• 2022

영어 교육 시장이 증대되면서 영어 학습을 효과적으로 지원하는 다양한 학습 시스템들이 개발되고 있다. 영어문장을 구성하는 기본적인 단위는 어휘로 문장 전체의 의미를 파악하기 위해서는 어휘의 의미를 이해하는 것이 필수적이다. 따라서 영어 어휘 능력 향상을 위한 다양한 영어 어휘 학습 시스템들이 개발되고 있으나, 어휘가 사용되는 문맥을 고려하거나 동시에 학습하면 효과적인 어휘 등 어휘 학습에 효과적인 교수학습 방법의 원리가 적용된 영어 어휘 학습 시스템에 대한 연구는 미비한 상황이다. 본 논문에서는 n 개의 영어 단어가 하나의 그룹으로 동시에 제시되면서 그 n개의 영어 단어가 모두 포함된 예문을 제공하는 지능형 영어 어휘 학습 시스템을 설계한다. 임의로 n 개의 영어 어휘가 주어졌을 경우 문맥에 맞게 영어 예문을 자동으로 생성하는 지능형 영어 문장 생성 모델이 본 연구의 핵심이다. 또한, 어휘 능력 평가에서 기존 어휘 학습 시스템과 같이 단순히 어휘를 얼마나 암기하고 있는지에 대한 평과 결과만을 제시하는 것이 아니라, 그룹별 취약 어휘 분석을 통해 효과적인 그룹 어휘 선택 규칙을 파악할 수 있는 기반을 마련하고자 한다. 본 논문에서 제안한 지능형 영어 어휘 학습 시스템을 통해 영어 어휘 학습자들의 학습 능력 향상에 도움이 될 것으로 기대한다.

• Journal of Educational Research in Mathematics
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• v.17 no.4
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• pp.395-418
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• 2007

The purpose of this study was to analyze the influence of mathematical tasks on mathematical communication. Mathematical tasks were classified into four different levels according to cognitive demands, such as memorization, procedure, concept, and exploration. For this study, 24 students were selected from the 5th grade of an elementary school located in Seoul. They were randomly assigned into six groups to control the effects of extraneous variables on the main study. Mathematical tasks for this study were developed on the basis of cognitive demands and then two different tasks were randomly assigned to each group. Before the experiment began, students were trained for effective communication for two months. All the procedures of students' learning were videotaped and transcripted. Both quantitative and qualitative methods were applied to analyze the data. The findings of this study point out that the levels of mathematical tasks were positively correlated to students' participation in mathematical communication, meaning that tasks with higher cognitive demands tend to promote students' active participation in communication with inquiry-based questions. Secondly, the result of this study indicated that the level of students' mathematical justification was influenced by mathematical tasks. That is, the forms of justification changed toward mathematical logic from authorities such as textbooks or teachers according to the levels of tasks. Thirdly, it found out that tasks with higher cognitive demands promoted various negotiation processes. The results of this study implies that cognitively complex tasks should be offered in the classroom to promote students' active mathematical communication, various mathematical tasks and the diverse teaching models should be developed, and teacher education should be enhanced to improve teachers' awareness of mathematical tasks.