• Microbiology and Biotechnology Letters
• /
• v.19 no.6
• /
• pp.583-587
• /
• 1991

A threonine overproducer, E. coli TF427, which is resistant to threonine analogue, a-amino-(3-hydroxyvaleric acid (AHV), and requires both methionine and isoleucine was developed by the mutations of E, coli W3110 using N-methyl-Nf-nitro-N-nitrosoguanidine (NTG) and UV. The E. coli TF427 produced 46.5 gll of threonine in a 5-L jar fermentor after 44 hr cultivation. The aspartokinase I of TF427 was not inhibited by threonine, and its synthesis was not repressed by threonine plus isoleucine.

• Journal of Biosystems Engineering
• /
• v.31 no.1 s.114
• /
• pp.24-32
• /
• 2006

Compaction is becoming a greater concern in crop production and the environment because it can have deleterious effects on growing conditions that are difficult to remediate. Because compaction can vary considerably from point to point within a field, and also from depth to depth within the soil profile, it is important to consider quantification and management of the spatial and vertical variability in soil compaction when developing an overall site-specific crop management plan. In this paper, the importance of soil compaction, techniques for quantification of its variability, and the concept of site-specific tillage are examined. Methods and systems to detect within-field variation in soil strength as a surrogate measure of soil compaction and related soil properties are also compared and discussed. Quantification of variability in soil compaction and site-specific compaction management was motivated recently, and sensors and control systems are still under development. Future study will need to address a number of issues related to understanding and applying the sensor measurements.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.13 no.6
• /
• pp.284-289
• /
• 2003

The electric furnace, inside which the desired temperature is kept by the generated heat, is known to be a difficult system to control and model exactly because system parameters and response delayed time are varied as the temperature and positions are changed. In this study, the GPCEW (generalized predictive control with exponential weight), which always guarantees the stability of the closed loop system and can be effectively applied to the internally unstable system, was introduced to the ceramic drying electric furnace and was verified by showing its temperature tracking performance experimentally.

• Journal of Biomedical Engineering Research
• /
• v.21 no.2
• /
• pp.219-224
• /
• 2000

본 연구는 몸통의 반복적인 flexion/extension 동작 수행시 근전도신호를 측정하고 이들 신호에서 나타난 EMG parameters(median frequency, median power, RMS) 와 피실험자의 주관적 불편도의 변화양상간의 정량적인 관계를 알아보고자 수행되었다. 피실험자별로 3-5회 정해진 업무를 수행하였고 주관적불편도와 근전도 신호를 측정하였다. 실험결과 반복횟수가 증가할수록 주관적 불편도는 증가하였으며 각 task 별로 EMG parameter와 불편도의 증감율 간의 회귀분석과 상관분석을 수행한 결과 실험과 EMG parameter에 따른 변이는 존재했지만 대체로 RMS에 비해 MF와 MP의 증감율이 불편도 증감율과 상관관계가 높은 것으로 나타났다.

• Korean Journal of Plant Resources
• /
• v.17 no.1
• /
• pp.20-23
• /
• 2004

These studies were carried out to develop native Calanthe in Korea. Calanthe native to southern islands in korea has beautiful flowers with various color and sweet fragrance, and it has been reported to have very good ornamental value. Concerning the classified 57 lines had surveyed their characteristics during the three years, and confirmed which that had manifestation stably. And then, a line was developed and given a name of horticultural cultivar to ‘Saegdong’. The major characteristics of the selected line, ‘Saegdong’, were as follows. In its color of flower, sepal was reddish orange, petal was yellow and lip was yellow. ‘Saegdong’ had a bended-inner blooming type.

• Korean Journal of Child Studies
• /
• v.27 no.6
• /
• pp.249-261
• /
• 2006

This study investigated the influence of socio-environmental variables and cognitive variables on adolescent depression. Subjects were 494 middle and high school students of Deagu. The instrument was a self-report questionnaire; data were analyzed by t-test, stepwise multiple regression and path analysis. Among Socio-environmental variables, social support variables had a stronger effect on depression than stress. Among cognitive variables, automatic thought had a stronger effect on depression than cognitive distortion and socio-environmental variables. In path analysis, social support had a direct effect on cognitive distortion and automatic thought. Automatic thought served as a mediater of the relation between social support and depression. Although adolescent stress resulted in high depression, its effect on depression varied with the level of perceived social support.

• The KIPS Transactions:PartA
• /
• v.8A no.4
• /
• pp.455-460
• /
• 2001

For some applications, the computational structure changes dynamically during the program execution. When this happens, static partitioning and allocation of tasks are not enough to achieve high performance in parallel computers. In this paper, we propose a dynamic load balancing algorithm efficiently distributes the computation with dynamically growing tree structure to processors. We present an implementation technique for the algorithm on mesh architectures, and analyze its complexity. We also demonstrate through experiments how our algorithm provides good quality solutions.

• Journal of Broadcast Engineering
• /
• v.9 no.3
• /
• pp.236-245
• /
• 2004

A multiview sequence CODEC with view scaiability is proposed in this paper. We define a GGOP (Group of GOP) structure as a basic coding unit to efficiently code multiview sequences. 7he proposed CODEC provides flexible GGOP structures based on the number of views and baseline distances among cameras. Multiview sequences encode consists of disparity estimation/compensation, motion estimation/compensation, residual coding and rate control and generates multiview sequence bitstream. The main bitstream is the same as an MPEG-2 mono-sequence bitstream for MPEG-2 compatibility. The auxiliary bitstream contains information concerning the remaining multiview sequences except for the reference sequences. The proposed CODEC with view scalability provides that a number of view flints are selectively determined at the receiver according to the type of display modes. The proposed multiview sequence CODEC is tested with several multiview sequences to determine its flexibility. compatibility with MPEG-2 and view scaiability. In addition, we subjectively confirm that the decoded bitstreams with view scaiability can be Properly displayed by several types of display modes. including 3D monitors.

• Journal of Korean Society of Forest Science
• /
• v.81 no.4
• /
• pp.320-324
• /
• 1992

It has been reported that there are two distinct phenotypes in Fraxinus mandshurica Rupr. growing in Korea. Recently developed polymerase chain reaction(PCR) was used to detect DNA sequence polymorphism in the species. Using a thermostable DNA polymerase and synthetic DNA primers, unknown DNA sequences from the species were randomly amplified. The two types of the species produced different DNA amplification pattern with three different primers tested. Although DNA polymorphism was detected among individuals within types, each type has its own distinct pattern. The two types could be easily differentiated by trier characteristic predominant bands.

• Applied Chemistry for Engineering
• /
• v.24 no.2
• /
• pp.155-160
• /
• 2013

Research on mutant generation and isolation for microalgae yielding enhanced lipid accumulation is an important issue for the production of economic biodiesel. In the present study, ultraviolet (UV-B type) ray induced mutant generation was tried using a photosynthetic microalgae, Nannochloropsis oculata (N. oculata), for the production of biodiesel. The resulting colonies were isolated and further cultured with both liquid and solid state f/2 media. After a few week cultivation, changes of cell growth rate, dry cell weight, and several important intracellular components (chlorophyll, carotenoid, and lipid) were investigated. Two mutants among thousands colonies showed an increased cell growth and high lipid accumulation as compared to those of wild type. It was also observed that the increased cell growth rate is associated with the overexpressed intracellular proteins. However, the mutants showed a decrease in the chlorophyll biosynthesis.