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A Study on the Characteristics of Tropical Cyclone Passage Frequency over the Western North Pacific using Empirical Orthogonal Function (경험적 직교함수를 이용한 북서태평양 열대저기압의 이동빈도 특성에 관한 연구)

  • Choi, Ki-Seon;Kang, Ki-Ryong;Kim, Do-Woo;Hwang, Ho-Seong;Lee, Sang-Ryong
    • Journal of the Korean earth science society
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    • v.30 no.6
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    • pp.721-733
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    • 2009
  • A pattern of tropical cyclone (TC) movement in the western North Pacific area was studied using the empirical orthogonal function (EOF) and the best track data from 1951 to 2007. The independent variable used in this study was defined as the frequency of tropical cyclone passage in 5 by 5 degree grid. The $1^{st}$, $2^{nd}$ and $3^{rd}$ modes were the east-west, north-south and diagonal variation patterns. Based on the time series of each component, the signs of first and second mode changed in 1997 and 1991, respectively, which seems to be related to the fact that the passage frequency was higher in the South China Sea for 20 years before 1990s, and recent 20 years in the East Asian area. When the eigen vectors were negative values in the first and second modes and TC moves into the western North Pacific, TC was formed mainly at the east side relatively compared to the case of the positive eigen vectors. The first mode seems to relate to the pressure pattern at the south of Lake Baikal, the second mode the variation pattern around $30^{\circ}N$, and the third mode the pressure pattern around Japan. The first mode was also closely related to the ENSO and negatively related to the $Ni\tilde{n}o$-3.4 index in the correlation analysis with SST anomalies.

Dynamic Behavior of Reactor Internals under Safe Shutdown Earthquake (안전정기지진하의 원자로내부구조물 거동분석)

  • 김일곤
    • Computational Structural Engineering
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    • v.7 no.3
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    • pp.95-103
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    • 1994
  • The safety related components in the nuclear power plant should be designed to withstand the seismic load. Among these components the integrity of reactor internals under earthquake load is important in stand points of safety and economics, because these are classified to Seismic Class I components. So far the modelling methods of reactor internals have been investigated by many authors. In this paper, the dynamic behaviour of reactor internals of Yong Gwang 1&2 nuclear power plants under SSE(Safe Shutdown Earthquake) load is analyzed by using of the simpled Global Beam Model. For this, as a first step, the characteristic analysis of reactor internal components are performed by using of the finite element code ANSYS. And the Global Beam Model for reactor internals which includes beam elements, nonlinear impact springs which have gaps in upper and lower positions, and hydrodynamical couplings which simulate the fluid-filled cylinders of reactor vessel and core barrel structures is established. And for the exciting external force the response spectrum which is applied to reactor support is converted to the time history input. With this excitation and the model the dynamic behaviour of reactor internals is obtained. As the results, the structural integrity of reactor internal components under seismic excitation is verified and the input for the detailed duel assembly series model could be obtained. And the simplicity and effectiveness of Global Beam Model and the economics of the explicit Runge-Kutta-Gills algorithm in impact problem of high frequency interface components are confirmed.

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The Effect of the Anthracnose Resistant Chili Pepper (PepEST gene) on the Non-target Insects, Green Peach Aphids (Myzus persicae Sulzer, Homoptera) (유전자 변형 탄저병 저항성 고추(PepEST gene)가 비표적 곤충인 복숭아혹진딧물(Myzus persicae Sulzer)에 미치는 영향)

  • Park, Ji-Eun;Yi, Hoon-Bok;Kim, Chang-Gi;Jeong, Soon-Chun;Yoon, Won-Kee;Park, Kee-Woong;Lee, Bum-Kyu;Kim, Hwan-Mook
    • Korean journal of applied entomology
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    • v.46 no.3
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    • pp.343-348
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    • 2007
  • To assess the environmental risks of transgenic chili pepper with PepEST gene on non-target organisms before it exposes to the agro-ecosystem environments, we conducted the three sets of green peach aphids (Myzus persicas S.) life table experiment under laboratory conditions (Temp. $25^{\circ}C$, R.H. 50-70%, Photoperiod L16 : D8) in series during 2005-2006. We measured the net reproductive rate ($R_0)^*$, the intrinsic rate of increase ($r_m$), the mean generation time ($T_c$), $fecundity^*$, life span, and reproduction period between non-transgenic chili peppers and transgenic chili peppers, respectively. The life span of green peach aphids from three sets was 31, 27, 25 days, and the period of life span was similar to the general average length of green peach aphids, 25-29 days. Although the first reproduction of transgenic pepper was similar to the non transgenic pepper (P>0.05), the fecundity and the net reproductive rate ($R_o$) by using Jackknife method of transgenic pepper were lower than those of non transgenic pepper (P<0.05). Conclusively, we observed the adverse effect from our results but we should execute further experiments to confirm the results at the fields with the similar way.

Price Volatility, Seasonality and Day-of-the Week Effect for Aquacultural Fishes in Korean Fishery Markets (수산물 시장에서의 양식 어류 가격변동성.계절성.요일효과에 관한 연구 - 노량진수산시장의 넙치와 조피볼락을 중심으로 -)

  • Ko, Bong-Hyun
    • The Journal of Fisheries Business Administration
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    • v.40 no.2
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    • pp.49-70
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    • 2009
  • This study proviedes GARCH model(Bollerslev, 1986) to analyze the structural characteristics of price volatility in domestic aquacultural fish market of Korea. As a case study, flatfish and rock-fish are analyzed as major species with relatively high portion in an aspect of production volume among fish captured in Korea. For analyzing, this study uses daily market data (dating from Jan 1 2000 to June 30, 2008) published by the Noryangjin Fisheries Wholesale Market which is located in Seoul of Korea. This study performs normality test on trading volume and price volatility of flatfish and rock-fish as an advanced empirical approach. The normality test adopted is Jarque-Bera test statistic. As a result, first, a null hypothesis that "an empirical distribution follows normal distribution" was rejected in both fishes. The distribution of daily market data of them were not only biased toward positive(+) direction in terms of kurtosis and skewness, but also characterized by leptokurtic distribution with long right tail. Secondly, serial correlations were found in data on market trading volume and price volatility of two species during very long period. Thirdly, the results of unit root test and ARCH-LM test showed that all data of time series were very stationary and demonstrated effects of ARCH. These statistical characteristics can be explained as a reasonable ground for supporting the fitness of GARCH model in order to estimate conditional variances that reveal price volatility in empirical analysis. From empirical data analysis above, this study drew the following conclusions. First of all, from an empirical analysis on potential effects of seasonality and the day of week on price volatility of aquacultural fish, Monday effects were found in both species and Thursday and Friday effects were also found in flatfish. This indicates that Monday is effective in expanding price volatility of aquacultural fish market and also Monday has higher effects upon the price volatility of fish than other days of week have since it has more new information for weekend. Secondly, the empirical analysis led to a common conclusion that there was very high price volatility of flatfish and rock-fish. This points out that the persistency parameter($\lambda$), an index of possibility for current volatility to sustain similarly in the future, was higher than 0.8-equivalently nearly to 1-in both flatfish and rock-fish, which presents volatility clustering. Also, this study estimated and compared and model that hypothesized normal distributions in order to determine fitness of respective models. As a result, the fitness of GARCH(1, 1)-t model was better than model where the distribution of error term was hypothesized through-distribution due to characteristics of fat-tailed distribution, was also better than model, as described in the results of basic statistic analysis. In conclusion, this study has an important mean in that it was introduced firstly in Korea to investigate in price volatility of Korean aquacultural fishery products, although there was partially a limited of official statistic data. Therefore, it is expected that the results of this study will be useful as a reference material for making and assessing governmental policies. Also, it is looked forward that the results will be helpful to build a fishery business plan as and aspect of producer, and also to take timely measures to potential price fluctuations of fishery products in market. Hence, it is advisable that further studies related to such price volatility in fishery market will extend and evolve into a wider variety of articles and issues in near future.

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Developing Korean Forest Fire Occurrence Probability Model Reflecting Climate Change in the Spring of 2000s (2000년대 기후변화를 반영한 봄철 산불발생확률모형 개발)

  • Won, Myoungsoo;Yoon, Sukhee;Jang, Keunchang
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.18 no.4
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    • pp.199-207
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    • 2016
  • This study was conducted to develop a forest fire occurrence model using meteorological characteristics for practical forecasting of forest fire danger rate by reflecting the climate change for the time period of 2000yrs. Forest fire in South Korea is highly influenced by humidity, wind speed, temperature, and precipitation. To effectively forecast forest fire occurrence, we developed a forest fire danger rating model using weather factors associated with forest fire in 2000yrs. Forest fire occurrence patterns were investigated statistically to develop a forest fire danger rating index using times series weather data sets collected from 76 meteorological observation centers. The data sets were used for 11 years from 2000 to 2010. Development of the national forest fire occurrence probability model used a logistic regression analysis with forest fire occurrence data and meteorological variables. Nine probability models for individual nine provinces including Jeju Island have been developed. The results of the statistical analysis show that the logistic models (p<0.05) strongly depends on the effective and relative humidity, temperature, wind speed, and rainfall. The results of verification showed that the probability of randomly selected fires ranges from 0.687 to 0.981, which represent a relatively high accuracy of the developed model. These findings may be beneficial to the policy makers in South Korea for the prevention of forest fires.

A Study on the Micro Discourse about Urban Parks in Blogs - In the Case of the Seoul Forest - (블로그(Blog)에 나타난 도시공원 미시담론 - 서울숲을 대상으로 -)

  • Lee, Jaei;Sung, Jong-Sang
    • Journal of the Korean Institute of Landscape Architecture
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    • v.43 no.1
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    • pp.29-39
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    • 2015
  • This study has attempted to determine the micro-discourse from blogs as personal media that reflect citizens' actual opinions of the Seoul Forest without intervention of experts. Furthermore, a qualitative research method discourse analysis was selected to analyze the micro-discourse regarding the Seoul Forest in a time series. The extracted samples of blogs by year were intended to identify the comment section of the process of change and the discursive structure. The results are as follows; first, from the beginning of the development of the Seoul Forest to the present, it is divided into four chronological periods along with individuals' micro-discourse with social changes. During the beginning of the development of the Seoul Forest, the social discourse was formed, and in the next period, the micro-discourse was developed with a more emotional and complex discourse. In the formative period, four or five years later, the discourse reflected the civic consciousness of development more than ever, showing the diversity of participation in the program at the Seoul Forest. In the growth period, as the users' experiences had been accumulated, the users started writing about the role of the Seoul Forest in their own words. This can also be called place discourse. From the individuals' micro-discourse, this study shows the discourse structure of how individuals think about the Seoul Forest in each period. Unlike the experts, the micro-discourse contains specific daily interactions, experiences, and the stories of individuals who actually use the parks. It also shows how users reproduce and understand the space. In this respect, this is the most significant finding of this study. Based on this research, this study has demonstrated that the emotional description of a place that actually functions as a discourse about city parks, and confirms that blogs could be used as a space to form discourse and as a research tool to read the trends. In accordance with these results, this study has described not only the discourse of experts, but also how the discourse of individuals' comments can be an important part of the discourse of modern urban parks.

A Study on the Manual Skills of Experimental Apparatuses of Preservice Elementary School Teachers (초등 예비교사의 실험 기구 조작 능력에 대한 연구)

  • Lee, So-Ree;Choi, Hyun-Dong;Lim, Jae-Keun;Shin, Se-Young;Yang, Il-Ho
    • Journal of Science Education
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    • v.35 no.1
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    • pp.80-90
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    • 2011
  • The purpose of this study is to investigate manual skills of experimental apparatuses of pre-service elementary school teachers by examining and analyzing the process of experiments conducted by pre-teachers. For this study, 24 pre-service elementary school teachers were selected as the subjects and 4 experimental apparatuses were chosen through analyzing science textbooks from 3rd grade to 6th grade in elementary school. The selected experimental apparatuses were alcohol burner, dropper, microscope, instruments for making a prepared specimen. In addition, a task was carefully chosen to conduct an investigation in real settings and a series of evaluation standards was developed. While 3 subjects conducted experiments in separated and independent space at the same time, 3 collaborators observed the experiment process and recorded whether the subject met the evaluation standards or not, using O, X. The study suggests that pre-service elementary school teachers' manual skills of experimental apparatuses were under far below our projections. Particularly, in case of alcohol burner, the subjects showed lower ability to properly light the burners - which is to brush through the lampwick with fire - and to adjust the height of tripods according to the flame. Also, when it comes to dropper, they were not held the way they were supposed to be. In addition, when designing prepared specimen, the subjects used their hands instead of tweezers and often skipped the process of dripping water drop and wiping water with an oilpaper. Moreover, they did not know how to use a microscope properly so there were many times that they could not focus a microscope, failing to observe the objects. Educational implications are discussed.

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Results of Arthroscopic Debridement of the Elbow Osteoarthritis (주관절 골관절염에서 관절경적 변연절제술 후 결과)

  • Chun, Churl-Hong;Kim, Jung-Woo;Lim, Jae-Chang
    • Clinics in Shoulder and Elbow
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    • v.12 no.1
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    • pp.53-60
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    • 2009
  • Purpose: Primary osteoarthritis on the elbow is the result of the growth of osteophytes and contracture of the capsule. It often causes disability on joint motion and pain while exercising. As arthroscopy has developed, the arthroscopic diagnosis and treatment of the elbow have recently become more generalized as well. Therefore, we like to report on arthroscopy for treating elbow arthritis and its results. Materials and Methods: This study includes 23 cases of elbow arthritis that were seen between 2005 June to 2007 June and these patients didn't response to conservative treatment. From this we excluded 18 cases that underwent arthroscopic surgery and among these 18 cases, 6 cases underwent ulnar nerve transfer. The average observation time was 21.3 months and the average age was 48.4 years (range: 22-66 years). The pre and post operative pain was evaluated with using the Visual Analogue Scale (VAS) and functional evaluation was done with using the Mayo elbow Performance Score (MEPS) with the range of joint motion. Results: The VAS score at the last follow up was significantly decreased from 3.4 to 1.9 compare to the preoperative score. The range of joint motion was improved by 25 (0-40) to 8.5 (0-20) in extension and 101.7 (80-140) to 125.2 (85-140) in flexion (p<0.05). The MEPS always showed significant improvement by showing an increase from 65.4 (40-85) to 87.9 (55-100). However, 3 cases showed a decreased range of motion after the operation. One case showed ulnar nerve symptoms after surgery. Conclusion: An arthroscopic procedure can treat the pathologic processes associated with arthritis of the elbow and it was safe and effective in this series.

Pornographic Animation's Sexuality through Japanese Sex Culture (일본의 성문화를 통해 본 포르노그래피 애니메이션의 선정성)

  • Choi, Eun-Hye;Oh, Jin-Hee
    • Cartoon and Animation Studies
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    • s.36
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    • pp.281-302
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    • 2014
  • Human beings have advanced to release instinctive desire. Among the human desires, sexual desire is classed as a basic desire with appetite and has been expressed in many ways from prehistoric times to present. Despite the social and ethical restriction, expression of sexual image has been evolved with change of time and medium's development. Thanks to inventing the photograph technique, Change of pornographic image has showed a dramatic aspect since early 20th century. The video which delivers message more directly than the picture boosted this change, and the animation has experimented the expression methods and techniques numerously exceeding the limit of realistic image which reappeared by the device. In this thesis, I want to discuss how human beings express sexual desire in animation based on society's sex culture, and analyzed Japanese pornographic animation as its obvious cases. Japanese pornographic animation should be interpreted as the result of culture and society system's history. Through Heian, Edo and early Meiji period, Japanese sex culture has been kept very openly and preposterously. Transformation, metamorphosis, pedophilia, tentacle sex and exposure of specific body parts that are frequently appear in Japanese animation can be interpreted by ancient Japanese open sex culture like Wakashu, polygamy, sleeping in mixed sex group and pederasty. These Japanese odd sex culture is hard to find elsewhere and settled as intrinsic sexual expression in Japanese animation. This situation was institutionally severed by European Modernization's force at the end of World War II in 20th century. However, it seems they have been keeping their influence in a proper form until now. In this study, I discussed that pornographic animation should be interpreted in a frame of cultural phenomenon by researching the series of procedure that ancient Japanese open sex culture has been changed by the system. Sexuality which is found in general Japanese animation was started from their history, and the dichotomous expression about women can be understood that it is bent by institutionally regulated sexual opinion. Japanese history and culture can be understood that it is transformed to the dichotomy that are simultaneously according freedom of eroticism to the pornographic animation, and the fear and irresistible temptation about the woman's body as the other.

A Numerical and Experimental Study for Fry-drying of Various Sludge (슬러지 유중 건조에 대한 전산 해석 및 실험적 연구)

  • Shin, Mi-Soo;Kim, Hey-Suk;Kim, Byeong-Gap;Hwang, Min-Jeong;Jang, Dong-Soon;Ohm, Tae-In
    • Journal of Korean Society of Environmental Engineers
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    • v.32 no.4
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    • pp.341-348
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    • 2010
  • The basic principle of fry drying process of sludge lies in the rapid pressure change of sludge material caused by the change of temperature between oil and moisture due to the difference of specific heat. Therefore, the rapid increase of pressure in drying sludge induces the efficient moisture escape through sludge pores toward heating oil media. The object of this study is to carry out a systematic investigation of the influence of various parameters associated with the sludge fry drying processes on the drying efficiency. To this end, a series of parametric experimental investigation has been made together with the numerical calculation in order to obtain typical drying curves as function of important parameters such as drying temperature, sludge diameter, oil type and sludge type. In the aspect of frying temperature, especially it is found that the operation higher than $140^{\circ}C$ was favorable in drying efficiency regardless of type of waste oil employed in this study. The same result was also noted consistently in the investigation of numerical calculation, that is, in that the sludge particle drying was efficiently made over $140^{\circ}C$ irrespective of the change of particle diameter. As expected, in general, the decrease of diameter in sludge was found efficient both experiment and numerical calculation in drying due to the increased surface area per unit volume. In the investigation of oil type and property, the effect of the viscosity of waste oil was found to be more influential in drying performance. In particular, when the oil with high viscosity, a visible time delay was noticed in moisture evaporation especially in the early stage of drying. However, the effect of high viscosity decreased significantly over the temperature of $140^{\circ}C$. There was no visible difference observed in the study of sludge type but the sewage sludge with a slightly better efficiency. The numerical study is considered to be a quite useful tool to assist in experiment with more detailed empirical modeling as further work.