• Progress in Medical Physics
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• v.19 no.1
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• pp.73-79
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• 2008

Retinal prosthesis is regarded as the most feasible method for the blind caused by retinal diseases such as retinitis pigmentosa (RP) or age related macular degeneration (AMD). Recently Korean consortium launched for developing retinal prosthesis. One of the prerequisites for the success of retinal prosthesis is the optimization of the electrical stimuli applied through the prosthesis. Since electrical characteristics of degenerate retina are expected to differ from those of normal retina, we performed voltage stimulation experiment both in normal and degenerate retina to provide a guideline for the optimization of electrical stimulation for the upcoming prosthesis. After isolation of retina, retinal patch was attached with the ganglion cell side facing the surface of microelectrode arrays (MEA). $8{\times}8$ grid layout MEA (electrode diameter: $30{\mu}m$, electrode spacing: $200{\mu}m$, and impedance: $50k{\Omega}$ at 1 kHz) was used to record in-vitro retinal ganglion cell activity. Mono-polar electrical stimulation was applied through one of the 60 MEA channel, and the remaining channels were used for recording. The electrical stimulus was a constant voltage, charge-balanced biphasic, anodic-first square wave pulse without interphase delay, and 50 trains of pulse was applied with a period of 2 sec. Different electrical stimuli were applied. First, pulse amplitude was varied (voltage: $0.5{\sim}3.0V$). Second, pulse duration was varied $(100{\sim}1,200{\mu}s)$. Evoked responses were analyzed by PSTH from averaged data with 50 trials. Charge density was calculated with Ohm's and Coulomb's law. In normal retina, by varying the pulse amplitude from 0.5 to 3V with fixed duration of $500{\mu}s$, the threshold level for reliable ganglion cell response was found at 1.5V. The calculated threshold of charge density was $2.123mC/cm^2$. By varying the pulse duration from 100 to $1,200{\mu}s$ with fixed amplitude of 2V, the threshold level was found at $300{\mu}s$. The calculated threhold of charge density was $1.698mC/cm^2$. Even after the block of ON-pathway with L-(1)-2-amino-4-phosphonobutyric acid (APB), electrical stimulus evoked ganglion cell activities. In this APB-induced degenerate retina, by varying the pulse duration from 100 to $1200{\mu}s$ with fixed voltage of 2 V, the threshold level was found at $300{\mu}s$, which is the same with normal retina. More experiment with APB-induced degenerate retina is needed to make a clear comparison of threshold of charge density between normal and degenerate retina.

• Geotechnical Engineering
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• v.12 no.4
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• pp.157-178
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• 1996

Current design methods for reinforced earth structures take no account of the magnitude of the strains induced in the tensile members as these are invariably manufactured from high modulus materials, such as steel, where straits are unlikely to be significant. With fabrics, however, large strains may frequently be induced and it is important to determine these to enable the stability of the structure to be assessed. In the present paper internal design method of analysis relating to the use of fabric reinforcements in reinforced earth structures for both stress and strain considerations is presented. For the internal stability analysis against rupture and pullout of the fabric reinforcements, a strain compatibility analysis procedure that considers the effects of reinforcement stiffness, relative movement between the soil and reinforcements, and compaction-induced stresses as studied by Ehrlich 8l Mitchell is used. I Bowever, the soil-reinforcement interaction is modeled by relating nonlinear elastic soil behavior to nonlinear response of the reinforcement. The soil constitutive model used is a modified vertsion of the hyperbolic soil model and compaction stress model proposed by Duncan et at., and iterative step-loading approach is used to take nonlinear soil behavior into consideration. The effects of seepage pressures are also dealt with in the proposed method of analy For purposes of assessing the strain behavior oi the fabric reinforcements, nonlinear model of hyperbolic form describing the load-extension relation of fabrics is employed. A procedure for specifying the strength characteristics of paraweb polyester fibre multicord, needle punched non-woven geotHxtile and knitted polyester geogrid is also described which may provide a more convenient procedure for incorporating the fablic properties into the prediction of fabric deformations. An attempt to define improvement in bond-linkage at the interconnecting nodes of the fabric reinforced earth stracture due to the confining stress is further made. The proposed method of analysis has been applied to estimate the maximum tensions, deformations and strains of the fabric reinforcements. The results are then compared with those of finite element analysis and experimental tests, and show in general good agreements indicating the effectiveness of the proposed method of analysis. Analytical parametric studies are also carried out to investigate the effects of relative soil-fabric reinforcement stiffness, locked-in stresses, compaction load and seepage pressures on the magnitude and variation of the fabric deformations.

• Journal of Korean Home Economics Education Association
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• v.21 no.2
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• pp.23-43
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• 2009

This study examined the relativity between school uniform behavior(especially attitude toward school uniform, school uniform satisfaction, school uniform alteration) and attitude toward appearance in the adolescence. From November to December in 2007, 898 middle school and high school students from four schools in Jeollabuk-do Province were analyzed and the influence of relevant variables was understood to gather basic information about the fashion life in the adolescence. This study used SPSS 11.5 for Windows Program to conduct frequency analysis, factor analysis, reliability analysis, ${\chi}^2$-test, t-test, One-way ANOVA, Duncan's multiple comparison test, and Pearson's correlation. The following summarizes the findings of this study: The results of analysing the factors to the response attitude toward uniforms and attitude toward appearance and clothing attitude emerged four dimensions(fashion, symbolism, cleanliness, alternation), three dimensions(needs value conformity toward appearance). In attitude toward uniform, female students were more actively altering their uniforms than male students and middle school students were more sensitive to trends than high school students. However, high school students were more aware of the cleanliness and alteration of uniforms. Overall, most students were not very satisfied with their uniforms (design, color, texture). When students' attitude toward appearance and demographical characteristics were examined, it was found that female students were more aware of desire, value, and conformity in appearances than male students. By age, it was found that high school students were more aware than middle school students. Also, students receiving KRW 30,000 or more for monthly allowance were more aware than others who receive a lower amount between KRW 10,000 and KRW 20,000. Therefore, most students(62.1%) have experiences in altering uniforms. Especially, more female students and more high school students had such experiences. Uniform alteration is more related to attitude to appearance. In other words, students who choose to alter their uniforms are highly aware of desire, value, and conformity toward appearance. Students who are satisfied with all factors regarding attitude toward uniform, except for alteration, did not alter their uniforms that much. In addition, when the relativity between students' attitude toward appearance with uniform was considered, students that are not very satisfied with their uniforms were more aware of desire, value, and conformity toward appearance. In conclusion, it was found that students' attitude toward appearance and school uniform behavior are closely related and their interests in appearance lead to alteration of uniforms, the clothing in which they spend most time of the day. From now on, students' opinions shall be considered when selecting or designing school uniforms.

• Journal of Korean Home Economics Education Association
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• v.32 no.2
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• pp.141-157
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• 2020

This study analyzed the content of national-level curriculum documents for the purpose of reviewing the overall status of population education in elementary and secondary schools in South Korea. Based on the results of the analysis, directions for the future of population education at school were proposed. Both the 2007-Revised Curriculum and the 2009-Revised Curriculum contain the contents of population education as a 'Cross-curricular learning topic' in the general curriculum influenced by the low birth rate and ageing society, yet not in the current 2015-Revised Curriculum. Furthermore, when the curriculum documents for the ten common subjects corresponding to the 'National Common Basic Curriculum' proposed by the 7th Curriculum were examined, only 'Home Economics' curriculum at the secondary school level and 'Social Studies' curriculum at the elementary and the secondary school levels adequately reflected the subject goals, characteristics, contents and achievement standards that correspond to those of population education. Based on the results of the curriculum analysis, the following five directions for population education at school are drawn. First, the purpose of population education at school should be stated using gender-neutral terms of 'response to low-birth and aging society' and it has to be emphasized that it is not to intervene in natural childbirth. Second, the subject which deals directly with the goals, content elements, and achievement standards of population education should be designated as the leading subject for population education. Third, with its inter-disciplinary nature, population education should be able to provide quality contents for convergence education. Fourth, the government should provide policy support to the leading subjects for population education so that more high schools may select the subjects as elective courses. Fifth, teacher education should be improved to enhance teachers' perceptions on population. This study asserts that 'Home economics,' which deals with human daily lives, is an optimal subject that can reflect population education in connection with real life. To this end, policy support should be provided for 'Home economics' so that it may fulfill the mission as a leading subject of population education.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.12
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• pp.1830-1841
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• 2012

We investigated the changes in microbial and physicochemical characteristics of the raw materials of Saengsk (brown rice, barley, carrot, potato, Angelica utilis Makino and kale) during storage after treatment with slightly acidic electrolyzed water (SAEW). To confirm the antimicrobial effects of the treatment washing solutions as well as the physicochemical changes in chromaticity, we stored the raw materials of Saengsik for 5, 10, 15, 20, 25 and 30 days at storage temperatures of 4, 10, 15, 20, 25 and $30^{\circ}C$ in a shelf-life study. The effects of microbial inhibition were higher in carrot treated with SAEW than in that treated with NaOCl, as indicated by a 1.75 log CFU/g reduction. Moreover, a 1.54 log CFU/g reduction of total coliforms was achieved in brown rice in response to SAEW treatment, which was higher than NaOCl treatment at all storage temperatures and periods. The lightness, redness and yellowness values of the raw materials of Saengsik were not significantly affected by SAEW treatments, except for Angelica utilis Makino and kale, whereas SAEW treatment resulted in decreased chromaticity values when compared to the NaOCl treatment. Overall, there was a significant difference (p<0.05) between the efficacy of the SAEW and NaOCl treatments. These results indicate that washing with SAEW is an effective method to reduce the microorganisms and enhance the shelf-life of raw materials of Saengsik; therefore, it can be effectively used to sanitize ingredients of Saengik without affecting the other properties during storage.

• Korean journal of applied entomology
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• v.58 no.4
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• pp.355-362
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• 2019

Cotesia glomerata L., an internal parasitoid wasp, attacks the larvae of both the cabbage white butterfly (Artogeia rapae L.) and the diamondback moth (Plutella xylostella L.). It can be utilized as a natural biological enemy to control these two insect pests in the summer cabbage fields of the Korean highland areas. The developmental response and sex ratio of C. glomerata to various temperatures and its longevity were examined in the laboratory. The egg-to-larva and pupa stages of C. glomerata were 12.1 ± 2.1 and 6.4 ± 1.8 days, respectively, at 20℃, The developmental threshold for egg-to-larva and pupa stages were 7.7 and 8.5℃, respectively. The sex ratios of C. glomerata when reared under various temperatures were 61.0 ± 4.5% at 15℃, 44.2 ± 1.0% at 20℃, and 39.0 ± 2.3% at 25℃, and the incidence of females increased as the temperature decreased. The longevity of C. glomerata when fed a 10% sugar solution was 20.4 ± 0.2 days, while in adults without any feed, the longevity was 3.6 ± 0.1 days. Indoor reared C. glomerata adults were released into cabbage fields from 2007 to 2018, in early August of each year, and the outdoor parasitism rates were surveyed. The parasitism rates were found to increase gradually as the year passed (Y = 0.2696X + 2.8633, R² = 0.3994). The highest parasitism rate was observed in 2013 at 7.6%, and the lowest was in 2018 at 6.5 %. These results could be used as basic information for biological control of kimchi cabbage pests at highland fields.

• Journal of the Korean Institute of Landscape Architecture
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• v.37 no.1
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• pp.110-119
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• 2009

Sosang Pal-Kyung(瀟湘八景), which originated in China and means eight scenes of So River and Sang River, greatly influenced the poems and the pictures in East Asia for a long time and became a cultural phenomenon leading the stereotype of the traditional landscapes in Korea and Japan. Studies on 'Kyung(a scene)' such as 'Pal-Kyung(八景)', have been made continuously until now, but there are no results of a study intensively focusing on the meaning and the form of Sosang Pal-Kyung, which is the origin of the domestic Pal-Kyung culture. The goal of this study is to investigate the typical form observed in Sosang Pal-Kyung-Ga(瀟湘八景歌) and Sosang Pal-Kyung-Do(瀟湘八景圖), as a text of a cultural landscape, and to clear up the coherence structure between a recognition system and a way of thinking that existed in the cultural phenomenon of Sosang Pal-Kyung. In this study, the symbolism of Pal(八) was summarized and the surface structure and the correlation of each Kyung of Sosang Pal-Kyung was explained in light of semiotics through segmenting and disjointing the lexeme of a landscape while the coherence structure and the meaning of Sosang Pal-Kyung-Ga and Sosang Pal-Kyung-Do as a text were investigated. Sosang Pal-Kyung is based on the view of the Sun and the Moon(or Positive and Negative) and the Eight Trigrams(八卦) for divination and is a linguistic symbol in which human life and the principle of circulation and conversion of nature are expressed as characters and picture texts. Its structure has strong coherence and cohesion, which attempt to move the abstruse truth of nature into human consciousness by developing and corresponding the grammatical structure and form of the sentences and the implicative languages emphasizing the symbolism of the words to the characteristics of similarities and contrast. In addition, Sosang Pal-Kyung expresses human life, the processes of birth and death of nature and the mutual response dialectically by putting various factors of the landscape in the frame of regular formality and structure. It is considered that the image signs in Sosang Pal-Kyung emphasize the theory of circulation of human life and nature are narrative scenery, which one looks at with a contemplative view in the circulation system of the time and the season. The cultural phenomena of Sosang Pal-Kyung in the Joseon Dynasty, which had been handed down from the Goryeo Dynasty, had become the driving force of leading aesthetics of Joseon's art and literature by adding the scenery of the point of view of Sung Confucianism. Its coherence structure was changed, but its cohesion was handed down continuously so that it became not only the basic text of the traditional and cultural landscape but also, the typical Korean-style stereotype of a landscape.

• Child Health Nursing Research
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• v.6 no.2
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• pp.224-239
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• 2000

This descriptive study was conducted to understand the contents and degree of parental stress level in the NICU patients, and to give a baseline data in developing nursing intervention program. Subjects were the 62 mother of hospitalized newborn in NICU of 1 University Hospital in Taejon City from May 1st, 1999 to November 30th, 1999, who agreed to take part in this study. The instrument used in this study were Parental Stressor Scales : NICU(PSS:NICU) developed by Miles et al. and validated by 3 NICU practitioners and 3 child health nursing faculties. The questionnaire has 4 dimensions and 45 items; sight and sounds of NICU(5 items), babies' appearance and behavior(19 items), parental role alteration and relationship with their baby(10 items), communication with health team(11 items). The questionnaire asks parents to rate each item on a five-point Likert type scale that ranges from (1) to (5). Total scores representing overall stress from the NICU environment are calculated by summing response to each item. A high score indicates high stress. A subscale score is calculated by summing the responses to each item in the subscale. Cronbach's α coefficients were .93. The data was analyzed as average, Frequency, Standard deviation, t-test, ANOVA, Pearson correlation coefficient by use of SPSS/PC+. The results of this study is summarized as follows ; 1. The total perceived stress level score of mothers was slightly high(3.6±.7). The highest scored dimension was 'appearance and behavior of the baby'(3.9±1.5), and next were 'relationship with their baby and parental role change'(3.5±1.4), 'communication with health team'(3.4±.9), 'sight and sounds of NICU'(3.2±.8). 2. Two variables were statistically significant with PSS:NICU total scale ; mother's perceived severity of the baby's condition (r=.482, P=.002) and mother's religious attendance(t=2.83, P=.01). The more the mother perceive their baby's condition severe, the higher the total stress score. There were high stress score noted in the mother of no religious attendance. 3. Four variables were statistically significant with NICU environment subscale ; mother's educational background(F=3.45, P=.04), religious attendance(t=2.28, P=.04), sex of the baby(t=2.83, P=.01) and NICU patients' hospital day(r=.359, P=.004). That is mother with high educational background and girl baby were high NICU environment subscale score. 4. Four variables were statistically significant with appearance and behavior of the baby subscale ; when first saw baby(F=3.52, P=.04), incubator care(t=2.83, P=.01), mother's perceived severity of the baby's condition(r=.303, P=.017), number of NICU visit(r=.441, P=.002). That is, seeing the baby first in the NICU and recieved incubator care was very stressful. Also, the more the mother perceive their baby's condition severe and more NICU visit, the higher the appearance and behavior of the baby subscale stress score. 5. Four variables were statistically significant with relationship with their baby and parental role change subscale ; when first saw baby(F=3.37, P=.04), sex of the baby(t=2.36, P=.03), incubator care(t=5.60, P=.00), mother's perceived severity of the baby's condition(r=.401, P=.001). That is, seeing the baby first in the NICU and girl baby was very stressful. Also, the more the mother perceive their baby's condition severe, the higher the relationship with their baby and parental role change subscale stress score. 6. Three variables were statistically significant with communication with health team subscale ; mother's educational background (F=3.63, P=.04), incubator care(t=4.24, P=.00), gestational age(r=-.394, P=.047), and birth weight(r=-.460, P=.004). That is, mother with high educational background and receiving incubator care were high communication with health team subscale score. Also, the shorter the gestational age and smaller the baby's birth weight, the higher the communication with health team subscale score. In conclusion, information about physical environment of NICU, the mother's perceived severity of baby's illness state, maternal role change related variables and the knowledge of characteristics of NICU patients must be included in nursing intervention program of mother's of NICU patients in reducing the maternal stress and anxiety level.

• Journal of muscle and joint health
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• v.5 no.1
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• pp.57-71
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• 1998

This study purports to examine sociodemographic characteristics and those factors associated with osteoarthritis in women experiencing the disease in order to make suggestions for the prevention and management of osteoarthritis in women. The subjects were 143 women who were diagnosed to have osteoarthritis and under follow-up care at an outpatient department of a university-affiliated hospital. The data were collected through personal interviews by using the structured questionnaire between October 6 and October 24, 1997. The degree of daily living activities was measured with 24 items, which were made based upon Katz Index, Barthel Index and Functional Status Index. Each item has 4 response categories : (1) being able to do alone with any difficulty, (2) being able to do alone with some difficulty, (3) being able to do alone with the help of a person or an instrument, (4) not being able to do at all. The data was analyzed with correlation analysis, t-test, ANOVA, and regression analysis. The results are summarized as follows : 1. As for the age of the subjects, 59.4% were between 45 and 64 years, while 28% were 65 years and above. The subjects having religion were 71.7% and 44.1% of the subjects were protestants. The educational level was low : 31.5% graduated from elementary school, while 30.1% had no formal education. Those married subjects were 72%. Fifty nine percent of the subjects evaluated their economic status as middle class. 2. Those people from whom the subjects currently receive some help were spouses in 35.8% of the subjects. Likewise, 50% of the subjects indicated spouse as the people from whom they want to receive help. 3. The score of the ability of daily living activities ranged between 48 and 96, with the mean of 78.94. Those means of physical activity, ADL(activities of daily living) and IADL(instrumental activities of daily living) were 14.89, 13.97 and 50.09, respectively. Except for the items of carrying heavy stuff and of washing clothes in the sitting position the subjects showed independence in more than 90% of the items, where Independence is defined as being able to do alone or with the help of a person or an instrument. 4. The increase in age was a significant predictor of the decrease in the ability of daily living activities. Those graduated from middle school and above showed a significantly higher degree in the ability of daily living activities than those with less educational level. The married women revealed significantly higher scores in physical activity, ADL, and IADL than the unmarried ones. The ability of daily living activities was not significantly related to having religion, economic status and living with family. 5. The average duration of experiencing osteoarthritis was 4 years and 7 months. Regarding the site of the onset, 65% of the subjects indicated knees. The women with osteoarthritis for less than 3 years were 65%. The ability of daily living activities was significantly different by the duration of illness : the longer the duration of illness, the less the ability of activities. The above findings suggest the need for developing those programs for prevention disabilities in performing daily living activities and for managing diseases targeting the women of middle and old age, with low educational level, and with unmarried status. In addition, there should be developed an instrument for measuring the ability of daily living activities which reflects daily lives of Korean women with osteoarthritis in order to examine comprehensive effects of osteoarthritis on women's daily lives in this country.

• Information Systems Review
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• v.18 no.1
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• pp.57-78
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• 2016

Hacking has raised many critical issues in the modern world, particularly because the size and cost of the damages caused by this disruptive activity have steadily increased. Accordingly, many significant studies have been conducted by behavioral scientists to understand hackers and their practices. Nonetheless, only qualitative methods, such as interviews, meta-studies, and media studies, have been employed in such studies because of hacker sampling limitations. Existing studies have determined that intrinsic motivation was the dominant factor influencing hackers, and that their techniques were mainly acquired from online hacking communities. However, such results have yet to be causally proven. This study attempted to identify the causal factors influencing the motivational and environmental factors encouraging hackers to learn hacking skills. To this end, hacker community members using the theory of planned behavior were observed to identify the causal factors of their learning of hacking skills. We selected a group of students who were developing their hacking skills. The survey was conducted over a two-week period in May 2015 with a total of 227 students as respondents. After list-wise deletion, 215 of the responses were deemed usable (94.7 percent). In summary, the hackers were aware that hacking skills are considered socially unethical, and their attitudes toward the learning of hacking skills were affected by both intrinsic and extrinsic motivations. In addition, the characteristics of the online hacking community affected their perceived behavioral control. This study introduced new concepts in the process of conducting a causal relationship analysis on a hacker sample. Moreover, this research expanded the discussion on the causal direction of subjective norms in unethical research, and empirically confirmed that both intrinsic and extrinsic motivations affect the learning of hacking skills. This study also made a practical contribution by raising the educational and policy response issues for ethical hackers and demonstrating the necessity to intensify the punishment for hacking.