• Journal of Life Science
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• v.18 no.2
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• pp.206-212
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• 2008

The quorum sensing (QS) regulatory network has been the subject of extensive studies during recent years and has also attracted a lot of attention because it both positively and negatively regulates various putative virulence factors, although initially considered to be a specialized system of Vibrio fischeri and related species. In this study, to identify the novel materials which inhibit QS system of microorganisms, extracts of eighteen natural products were tested by bioassay using N-(3-oxohexanoyl)-$_L$-homoserine lactone and N-(3-oxooctanoyl)-$_L$-homoserine lactone synthesized in this experiment and an Agrobacterium tumefaciens NT1 biosensor strain containing a traI::lacZ fusion. The result indicated that the extracts of cabbage, leek, and onion exhibited the QS inhibition activity. Thus, materials contained in the extracts were isolated via recycling preparative HPLC and were purified via a JAIGEL-LS255 column. The common fraction corresponding to a peak of the 83 min point of them quenched the quorum sensing of A. tumefaciens NT1 biosensor strain in ABMM containing X-gal and was designated quorum sensing inhibitor-83 min (QSI-83). The QSI-83 exhibited the heat stability and did not inhibit the growth of A. tumefaciens NTl. Furthermore, thin layer chromatography (TLC) results suggested that these novel materials may be antagonists of N-acyl homoserine lactone or may inhibit the QS autoinducer synthesis by Pseudomonas syringae pv. tabaci.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.2
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• pp.627-633
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• 2020

Assembly process data can be gathered in real time in a manufacturing execution system (MES) server using proximity sensors, barcodes, RFID, ZigBee, Bluetooth, wireless sensor networks, etc. Although this is suitable for identifying process flow and checking production progress, it is difficult to trace the location of individual workers in real time for missing work or trajectories within the work area. To overcome this, the location and trajectory of the working tool can be analyzed in real time through a position tracking system of an operator's working tool. It can instruct the operator to perform a consistent working process. Productivity and quality improvement can be achieved by an alarming or blocking operator with possible assembly defects during the assembly process in real time. To this end, we developed a real-time tool position-tracking sensor system based on Ultra Wide Band (UWB) trilateration using a Kalman filter to eliminate mechanical vibration and radio communication noise.

• Women's Health Nursing
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• v.2 no.2
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• pp.284-297
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• 1996

A maternity ward in a hospital in Seoul has an educational program for postpartal mothers since its opening, but evaluation on the program has not been done. This study was to find whether the educational program contributed to increase of knowledge and confidence of the post-partal mothers in the area of postpartal self-care and the newborn baby care or not. This study aimed at improvement of the educational program for posrpartal mothers and the newborn babies. Subjects were 40 primiparae who were admitted to the obstetric ward in a general hospitals in Seoul from August 20th to September 10th, 1995. Subjects were those who had no labor pain at the admission time, had no complications during labor and delivery, gave a birth to a healthy baby, and agreed to participate in this study. All subjects were well educated and were in well-to-do group. Most of them received antenatal care adequately. They were tested on knowledge and self-confidence in the area of postpartal self-care and infant care two times, one at the admission time and the other prior to discharge. After the first test, nurses in a maternity ward and nursery taught them on postpartal self-care and infant care. Education consisted of a 1 hour planned program and incident teachings done at bed side. Four tools were developed by authors based literature review. The test tool for knowledge of postpartal self-care consisted of 15 items which included the definition of postpartum, dangerous symptoms in postpartum, lochia, time to begin coitus, postpartum exercise, sitz-bath, and perineal care. The test tool for self-confidence in postpartal self-care included such items as emergency care on dangerous symptoms in postpartum, sexual life and contraception after postpartum, self-confidence in postpartum exercise and perineal care. The test tool for knowledge of newborn baby care consisted of 18 items which included bathing, umbilical cord care, vaccination, breast feeding, abnormal symptoms of neonate. The test tool for self confidence in the newborn baby care included umbilical cord care, vaccination, breast feeding, emergency care for baby. Analysis of demographic data were analyzed with calculation of percentage. Score differences between the first test and the second test were analyzed with paired t-test. SAS / PC (Release 6.04 for DOS) program are as follows. 1. Mothers' knowledge of postpartal self-care increased significantly after education (t=10.04, df=38, p=0.0001). 2. Mothers' self-confidence in postpartal self-care increased significantly after education (t=6.53, df=38, p=0.0001). 3. Mother's knowledge of the newborn abay care increased significantly after education (t=9.74, df=38, p=0.0001). 4. Mothers' self-confidence in the newborn baby care increased significantly after education(t=8.22, df=38, p=0.0001) Suggestions for further studies and nursing practice were as follows. 1. We suggest studies by randomized control-group pretest-posttest design or nonequivalent control group pretest-posttest design will be done. 2. We suggest follow-up studies to find if mothers's confidence will last or not after discharge. 3. We suggest general hospitals to establish a phone-counseling system.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.3 no.3
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• pp.158-164
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• 1998

We introduce a statistical scheme to classify seabed from acoustic profiling data acquired using Chirp sonar system. The classification is based on grouping of signal traces by similarity index, which is computed using the K-L (Karhunen-Lo$\grave{e}$ve) transform of the Chirp profiling data. The similarity index represents the degree of coherence of bottom-reflected signals in consecutive traces, hence indicating the acoustic roughness of the seabed. The results of this study show that similarity index is a function of homogeneity, grain size of sediments and bottom hardness. The similarity index ranges from 0 to 1 for various types of seabed material. It increases in accordance with the homogeneity and softness of bottom sediments, whereas it is inversely proportional to the grain size of sediments. As a real data example, we classified the seabed off Cheju Island, Korea based on the similarity index and compared the result with side-scan sonar data and sediment samples. The comparison shows that the classification of seabed by the similarity index is in good agreement with the real sedimentary facies and can delineate acoustic response of the seabed in more detail. Therefore, this study presents an effective method for geoacoustic modeling to classify the seafloor directly from acoustic data.

• Economic and Environmental Geology
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• v.41 no.6
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• pp.747-761
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• 2008

In order to experiment the acoustic remote classification of seabed sediment, we achieved ground-truth data(i.e. video and grab samples, etc.) and developed post-processing for automatic classification procedure on the basis of 300 kHz MultiBeam Echo Sounder(MBES) backscattering data, which was acquired using KONGBERG Simrad EM3000 at Sock-Cho Port, East Sea of South Korea. Sonar signal and its classification performance were identified with geo-referenced video imagery with the aid of GIS (Geographic Information System). The depth range of research site was from 5 m to 22.7 m, and the backscattering amplitude showed from -36dB to -15dB. The mean grain sizes of sediment from equi-distanced sampling site(50 m interval) varied from 2.86$(\phi)$ to 0.88(\phi). To acquire the main feature for the seabed classification from backscattering amplitude of MBES, we evaluated the correlation factors between the backscattering amplitude and properties of sediment samples. The performance of seabed remote classification proposed was evaluated with comparing the correlation of human expert segmentation to automatic algorithm results. The cross-model perception error ratio on automatic classification algorithm shows 8.95% at rocky bottoms, and 2.06% at the area representing low mean grain size.

• Journal of the Korean School Mathematics Society
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• v.16 no.4
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• pp.797-820
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• 2013

This study intended on analyzing the error patterns of mathematic problem posing sentences by the 100 elementary pre-teachers and discussing about the solutions. The results showed that the problem posing sentences have five error patterns: phonological error patterns, word error patterns, sentence error patterns, meaning error patterns, and notation error patterns. Divided into fourteen specific error patterns, they are as in the following. 1) Phonological error patterns are consisted of the 'ㄹ' addition error pattern and the abbreviated word error pattern. 2) Words error patterns are divided with the inappropriate usage of word error pattern and the inadequate abbreviation error pattern, which are formulized four subgroups such as the case maker, ending of the word, inappropriate usage of word, and inadequate abbreviation of article or word error pattern in detail. 3) Sentence error patterns are assumed four kinds of forms: the reference, ellipsis of sentence component, word order, and incomplete sentence error pattern. 4) Meaning error patterns are composed the logical contradiction and the ambiguous meaning. 5) Notation error patterns are formed four patterns as the spacing, punctuation, orthography of Hangul, and spelling rules of foreign words in Korean. Furthermore, the solutions for these error patterns were discussed: First, it has to be perceived the differences between spoken and written language. Second, it has to be rejected the spoken expressions in written contexts. Third, it should be focused on the learning of the basic sentence patterns during the class. Forth, it is suggested that the word meaning should have the logical development perception based on what it means. Finally, it is proposed that the system of spelling of Korean has to be learned. In addition to these suggestions, a new understanding is necessary regarding writing education for college students.

• Geophysics and Geophysical Exploration
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• v.11 no.2
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• pp.148-152
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• 2008

Multichannel seismic profiles reveal a strong bottom simulating reflector (BSR) occurring below the seafloor in the plain of the Ulleung Basin, East Sea (Japan Sea). The essential characteristics of the BSR include its cross-cutting relationship to strata, strong amplitude, and reverse polarity with respect to the seafloor reflection, representing the base of the gas hydrate stability zone (BHSZ). The BSR reflection coefficient ranging from -0.23 to -0.26 is 1.5${\sim}$1.7 times that of the seafloor reflection and interval velocities decrease to less than 700 m/s below the BSR. These features indicate the existence of free gas beneath the GHSZ. Heat flow, estimated from the BSR depth as $95{\sim}98mW/m^2$, is in good agreement with measured values. Therefore, the BSR can be efficiently used to estimate regional distribution of heat flow in the Ulleung Basin.

• The Journal of the Petrological Society of Korea
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• v.23 no.3
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• pp.187-195
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• 2014

In this paper, we report new OSL ages of the marine terrace sediments at Suryum fault site, using single grains of quartz, and briefly discuss their chronological implications on the timing of terrace formation along the southeastern coast of Korea. Of 1200 grains measured, 93 quartz grains were found to have OSL properties suitable for dating, the equivalent dose ($D_e$) values of which varied significantly, ranging from 50 Gy to 610 Gy with the overdispersion of $30{\pm}4%$. Applied to the Central Age Model (CAM) and Minimum Age Model (MAM), these quartz grains showed the OSL ages of $83{\pm}4ka$ and $60^{+3}{_{-7}}ka$, respectively, both of which are stratigraphically inconsistent with the previously reported OSL ages of lower $2^{nd}$ terrace (MIS 5a; ~80 ka). However, Finite Mixture Model (FMM) revealed that a small fraction of the measured quartz grains ($6{\pm}4%$) were of the ages ($194{\pm}24ka$) corresponding to MIS 7. Conclusively, based on single grain OSL ages, it would be prudent not to exclude the possibility that the marine terrace sediments at Suryum fault site have formed during MIS 7. Further, our single grain OSL ages imply that multiple grain(single aliquot) OSL dating methods are not applicable to the marine sediments at Suryum fault site.

• The Journal of the Korea Contents Association
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• v.21 no.9
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• pp.75-87
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• 2021

The purpose of this study is to derive the characteristics of interaction design for each stage of content composition so that it can be referred to in the planning and production of virtual reality safety education contents. It was confirmed that each of the following interaction design features was found in the three configuration steps: acquisition of situation response procedure knowledge, accident situation experiential learning, and content confirmation and evaluation. First, it was revealed that the quality of experience was controlled by increasing the fidelity of behaviors and reducing general and repetitive behaviors in order to emphasize the educational content-related experiences in the learner experience stage. Second, in order for learners to easily recognize main interaction objects in order to acquire information on safe behavior procedures in unfamiliar environments, use of spatial UI or signifiers using arrows or symbols, posts that specifically instruct actions, and multisensory signals Therefore, it was found to be important to emphasize essential actions in a way that lowers the degree of freedom of user experience, and the proportion of non-realistic interactions for cognitive interactions was found to increase. Lastly, in the confirmation and evaluation stage of the experience, it is important to use the meta UI to alleviate negative experiences such as physical damage after experiencing a safety accident situation,

• Science of Emotion and Sensibility
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• v.5 no.2
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• pp.11-22
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• 2002

This study investigated the effects of mild mental imagery inducing pleasantness or unpleasantness and cognitive mental arithmetic task on skin conductance level. Subjects were f undergraduates(male 5, female 4). They were given the list of the words and asked to write down the liked objects and the disliked ones freely associated with these words. Among these objects the most-liked one and the most disliked one were selected as the self-induced mental imageries. Data-collection procedures were as follows ; first baseline, pleasant imagery, 2nd baseline, unpleasant imagery, finally 3rd baseline, and mental arithmetic task subtracting continuously 7 from the number 500. During these trials, the SCLs were recorded every 10 seconds. The results indicated that there were nonsignificant differences between the 3 trial-baselines ot each condition. This suggested that unlike the procedures used in the previous studies, our procedures would give the stability of the baseline level necessary for the comparison of the effects of several stimuli. Also, the level of skin conductance in mental arithmetic condition was significantly higher than that of the emotional mental imagery. This suggested the possibility that mental arithmetic task would gave rise to the higher physiological arousal in comparison to mental imageries. Overall, it was suggested that the procedures and the stimulus presentation methods used in this preliminary study could be useful for the data-collection techniques for The future study. Implications for the future study were presented.