• Korean Journal of Environmental Agriculture
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• v.10 no.1
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• pp.51-57
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• 1991

Field experiments were carried out to evaluate the utility of water hyacinth(Eichhornia crassipes Solm-Laub) for purifyng sewage water in paddy fields of $247m^2$(75 Pyung). A field was lined with PVC film at a depth of 30cm and sewage water for 40 days. The results obtained with the use of water hyacinth in the sewage water are summarized as follows : 1. The Sodium linear dodecyl benzene sulfonate content of sewage water on the inlet was 6.33 ppm, themiddle point was 3.50 ppm and the outlet was 1.37 ppm. 2. With the use of water hyacinth in the sewage and the distilled water, the L.A.S. content were decreased from 7.3 and 4.0 to 0, respectively. 3. Sterillization with 70% ethyl alcohol at the roots of the water hyacinth was reduced the degradation effect of L.A.S. 4. The COD and $NH_4^+-N$ content of the sewage decreased from 107 and 32.7 ppm to 32.6 and 16.2 ppm, respectively and the P, Na and Cl content also were reduced.

• Journal of Energy Engineering
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• v.28 no.4
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• pp.82-93
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• 2019

In this study, a new model is proposed to improve the problem of the decline of predict rate of heat demand on a particular date, such as a public holiday for the conventional heat demand forecasting system. The proposed model was the Four Season Mixed Heat Demand Prediction Neural Network Model, which showed an increase in the forecast rate of heat demand, especially for each type of forecast date (weekday/weekend/holiday). The proposed model was selected through the following process. A model with an even error for each type of forecast date in a particular season is selected to form the entire forecast model. To avoid shortening learning time and excessive learning, after each of the four different models that were structurally simplified were learning and a model that showed optimal prediction error was selected through various combinations. The output of the model is the hourly 24-hour heat demand at the forecast date and the total is the daily total heat demand. These forecasts enable efficient heat supply planning and allow the selection and utilization of output values according to their purpose. For daily heat demand forecasts for the proposed model, the overall MAPE improved from 5.3~6.1% for individual models to 5.2% and the forecast for holiday heat demand greatly improved from 4.9~7.9% to 2.9%. The data in this study utilized 34 months of heat demand data from a specific apartment complex provided by the Korea District Heating Corp. (January 2015 to October 2017).

• Journal of Elementary Mathematics Education in Korea
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• v.14 no.1
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• pp.1-22
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• 2010

The purpose of this study was to examine the relationship between teacher's role and interaction patterns in mathematics classrooms. Teacher's role was divided into usual practices with students, usual practices with content and usual practices with students and contents, and interaction patterns were classified into report, inquiry and discussion. The subjects in this study were teachers and students in three fourth- grade classes in T elementary school located in Seoul. After the classes of every math teacher were observed, three teachers who played distinctively unique roles were selected in accordance with the results of the first-semester autonomous supervision, of open class for parents and of the instructional observation. Thus, there was a close relationship between the teacher roles and interaction patterns. And it's concluded that students are able to have a more discussion on each other's ideas in the student-centered classroom, and that teachers should perform active roles in that process. Given the findings of the study, there are some suggestions: First, the teachers appeared to fulfill consistent roles when their videotaped classes, study aids and performance assessment materials were analyzed, and they should play more active roles in mathematics class. Second, they should try to create the kinds of climate that encourages students to come up with ideas in an active manner. Third, earlier studies had focused on student-teacher interaction patterns, but this study found that the roles of the teachers depended on interaction with not only students but study aids and performance assessment materials, and that the interaction patterns hinged on their roles as well. Therefore more profound research efforts should be directed into this issue.

• Journal of Educational Research in Mathematics
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• v.16 no.4
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• pp.313-326
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• 2006

본 연구는 중학교 2학년 141명의 학생을 대상으로 수학 창의성(Mathematical Creative Problem Solving Ability Test: KEDI, 1997)과 성격유형(Murphy-Meisgeier Type Indicator for Children: 심혜숙 김정택, 1993)과의 상관관계를 조사하였다. 자료 분석은 중학생의 성격 특성을 알아보기 위하여 유형별로 빈도와 백분율을 산출하였고, 성격유형에 따른 수학 창의성의 차이를 검증하기 위하여 평한, 표준편차, t-test, ANOVA와 Duncan 사후검증을 실시하였다. 본 연구 결과는 다음과 같다. 첫 번째, 일반 중학교 2학년과 비교해 볼 때, 선호지표에서 연구 집단의 중학생은 표준화집단(심혜숙 김정택, 1993)보다 I(2.7%), J(3.9%)가 높았다. 두 번째, 수학 창의성과 성격유형을 살펴본 결과, 기질적 측면에서 유창성, 융통성, 수학 창의성 전체에서 NF형이 SJ, SP형에 비해 의미 있게 높았고, SJ형도 SP형에 비해 의미 있게 높게 나타났다. 세 번째, 성격유형 중에서 어떤 요인이 중학교 2학년의 수학 창의성을 잘 예측해 주는지를 살펴본 결과, 직관(N), 내향(I)이 수학 창의성의 예인변인으로서 유의하였다. 이러한 결과와 관련하여 수학 창의성 검사도구 및 수학창의성 프로그램 개발 시 직관과 내향을 우선적으로 고려하여야 한다. 네 번째 NT와 {SP, SJ, NF}는 통계적으로 유의미하게 같은 수준의 집단이 아니므로 직관적사고형(NT)이 감각적 감정형(SF), 감각적 사고형(ST), 직관적 감정형(NF)과는 독립된 특별한 요인으로 보인다. 직관적사고형(NT)은 조사와 개념 학습이나 소크라테스식의 문답법적인 학습과 문제해결학습을 선호하고 독립심이 지지되는 분위기의 학급을 선호한다. 따라서 수학 창의성 증진과 관련된 교육과정이나 프로그램개발 시 조사와 개념 학습이나 소크라테스식의 문답법적인 학습과 문제해결학습을 우선적으로 고려하여야 할 것이다. 연구 결과와 관련하여 연구의 제한점과 후속연구를 위한 제언은 다음과 같다. 첫째, 연구대상이 특정지역의 중학교 2학년 학생이므로 연구결과를 우리나라 중학교 2학년으로 일반화시키는데는 무리가 있을 수 있다. 따라서 후속연구에서는 연구대상의 표집을 확대하여 볼 필요가 있다. 둘째, 수학 창의성과 성격유형간의 관계와 관련하여 수학 창의성과 성격유형의 각 하위 차원들 간에 적률 상관계수를 통해 상관관계를 분석해 보는 것이 필요하다. 셋째 직관과 내향 및 조사와 개념 학승이나 소크라테스식의 문답법적인 학습과 문제해결학습을 고려한 수학 창의성 프로그램이 개발할 필요가 있다.

• The Journal of the Korean Society for Microbiology
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• v.21 no.4
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• pp.441-446
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• 1986

Previous studies have demonstrated that phagocytosis of encapsulated bacteria needs the opsonization of bacteria with immunoglobulin and complement. Several investigators have studied the role of specific antibody to the bacteria. The purpose of this study is to investigate the role of specific anti-Actinobacillus actinomycetemcomitans Y4($A{\alpha}Y4$) antibody, which was obtained from the immunized rabbit serum for phagocytosis of $A{\alpha}Y4$ by PMNL. For this study, specific and nonspecific IgG were separated from the sera of the rabbits and PMNL were isolated from 15 healthy adults. By an enzyme-linked immunosorbent assay, the results showed that the binding capacity of anti-$A{\alpha}Y4$ IgG to $A{\alpha}Y4$ was much higher than that of nonspecific IgG; 0.75 and 0.14(O.D. at 400nm), respectively. The oxygen consumption of PMNL, phagocytizing $A{\alpha}Y4$ which was opsonized with specific $A{\alpha}Y4$ IgG(37.13 nmol/min/$1{\times}10^7$ PMNL), was significantly higher than that with nonspecific IgG(27.95 nmol/min/$1{\times}10^7$ PMNL, p<0.01). In immunofluorescence microscopic examination, the difference between the numbers of the ingested $A{\alpha}Y4$ opsonized with specific anti-$A{\alpha}Y4$ IgG and nonspecific IgG reached to statistically significant level; $184{\pm}11.4$ and $133.2{\pm}8.3$ per 100 PMNL, p<0.05. These results suggest that specific anti-$A{\alpha}Y4$ IgG has a significant role in PMNL phagocytosis of encapsulated $A{\alpha}Y4$ and also it can be available to adopt this system to develop anti-capsular antibody to $A{\alpha}Y4$ for enhancing and emphasizing the phagocytic activity against this bacterium.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.30 no.2
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• pp.211-221
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• 2012

To utilize omni-directional images acquired by a rotating line camera for indoor spatial information services, we should register precisely the images with respect to an indoor coordinate system. In this study, we thus develop a georeferencing method to estimate the exterior orientation parameters of an omni-directional image - the position and attitude of the camera at the acquisition time. First, we derive the collinearity equations for the omni-directional image by geometrically modeling the rotating line camera. We then estimate the exterior orientation parameters using the collinearity equations with indoor control points. The experimental results from the application to real data indicate that the exterior orientation parameters is estimated with the precision of 1.4 mm and $0.05^{\circ}$ for the position and attitude, respectively. The residuals are within 3 and 10 pixels in horizontal and vertical directions, respectively. Particularly, the residuals in the vertical direction retain systematic errors mainly due to the lens distortion, which should be eliminated through a camera calibration process. Using omni-directional images georeferenced precisely with the proposed method, we can generate high resolution indoor 3D models and sophisticated augmented reality services based on the models.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.30 no.3
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• pp.241-247
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• 2012

The national geodetic reference frame of Korea switched to the International Terrestrial Reference Frame (ITRF) in 2003. In order to study the land area changes, we calculated the entire land area of Korea using the administrative boundaries of census data provided by Statistics Korea. The standard transformation procedure by the National Geographic Information Institute (NGII) was followed. The Transverse Mercator (TM) projected coordinates were transformed into the GRS80-based world geodetic reference frame, and the ellipsoidal and the projected areas were calculated. The provinces that range over two projection origins were divided into two polygons and projected using appropriate origins. After the transformation, all boundaries were shifted in the northwestern direction, resulting in a decreased area of $1.36km^2$ (about 0.0013%) on the projected plane. Moving the boundaries into a high latitude area cancels out the effect of the enlarged ellipsoid. In addition, the rate of change shows that a higher-latitude province is more sensitive to the shift of the boundaries. The data by Statistics Korea is significantly different from those of the Ministry of Land, Transport and Maritime Affairs (MLTM), thus it is urgently recommended that the data are integrated and unified.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.30 no.3
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• pp.295-303
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• 2012

Clarify wind energy productivity depends on three factors: the wind probability density function(PDF), the turbine's power curve, and the air density. The wind PDF gives the probability that a variable will take on the wind speed value. Wind shear refers to the change in wind speed with height above ground. The wind speed tends to increase with the height above ground. also, Wind PDF refers to the change with height above ground. Wind analysts typically use the Weibull distribution to characterize the breadth of the distribution of wind speeds. The Weibull distribution has the two-parameter: the scale factor c and the shape factor k. We can use a linear least squares algorithm(or Ln-least method) and moment method to fit a Weibull distribution to measured wind speed data which data was located same site and different height. In this study, find that the scale factor is related to the average wind speed than the shape factor. and also different types of terrain are characterized by different the scale factor slop with height above ground. The gross turbine power output (before accounting for losses) was caculated the power curve whose corresponding air density is closest to the air density. and air desity was choose two way. one is the pressure of the International Standard Atmosphere up to an elevation, the other is the measured air pressure and temperature to calculate the air density. and then each power output was compared.

• Economic and Environmental Geology
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• v.27 no.4
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• pp.345-361
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• 1994

Lens shaped titanomagnetite ore bodies in the Soyeonpyeong iron mine are embedded in amphibolites, which were intruded into Precambrian metasediments such as garnet-mica schist, marble, mica schist, and quartz schist. Mineral chemistry, K-Ar dating and hydrogen and oxygen stable isotopic analysis for the amphibolites and titanomagnetite ores were conducted to interpret petrogenesis of amphibolite and ore genesis of titanomagnetite iron ore deposits. Amphibolites of igneous origin have unusually high content of $TiO_2$, ranging from 0.94 to 6.39 wt.% with an average value of 4.05 wt.%. REE patterns of the different lithology of the amphibolite show the similar trend with an enrichment of LREE. Amphiboles of amphibolites are consist mainly of calcic amphiboles such as ferro-hornblende, tschermakite, ferroan pargasite, and ferroan pargasitic hornblende. K-Ar ages of hornblende from amphibolite and gneissic amphibolite were determined as $440.04{\pm}6.39Ma$ and $351.03{\pm}5.21Ma$, respectively. This indicates two metamorphic events of Paleozoic age in the Korean peninsula which are correlated with Altin orogeny in China. The titanomagnetite mineralization seems to have occurred before Cambrian age based on occurrence of orebodies and ages of host amphibolites. The Soyeonpyeong iron ores are composed mainly of titanomagnetite, ilmenite, and secondary minerals such as ilmenite and hercynite exsolved in titanomagnetite. The temperature and the oxygen fugacity estimated by the titanomagnetite-ilmenite geothermometer are $500{\sim}600^{\circ}C$ (ave. $550^{\circ}C$) and about $2{\pm}10^{-23}bar$, respectively. Hornblendes from ores and amphibolites which responsible for magnetite ore mineralization, have a relatively homogeneous isotopic composition ranging from +0.8 to +3.9 ‰ in ${\delta}^{18}O$ and from -87.8 to -113.3 ‰ in ${\delta}D$. The calculated oxygen and hydrogen isotopic compositions of the fluids which were in equilibrium with hornblende at $550^{\circ}C$, range from 2.8 to 5.9‰ in ${\delta}^{18}O_{H2O}$ and from -60.41 to -81.31 ‰ in ${\delta}D_{H2O}$. The ${\delta}^{18}O_{H2O}$ value of magnetite ore fluids are in between +6.4 to + 7.9 ‰. All of these values fall in the range of primary magmatic water. A slight oxygen shift means that $^{18}O$-depleted meteoric water be acted with basic fluids during immiscible processes between silicate and titaniferous oxide melt. Mineral chemistry, isotopic compositions, and occurences of amphibolites and orebodies, suggest that the titanomagnetite melt be separated immisciblely from the titaniferous basic magma.

• Journal of Animal Science and Technology
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• v.55 no.3
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• pp.179-184
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• 2013

Willingness-to-pay (WTP) for pork produced by quality test was determined using a contingent valuation method. Three model studies including a dichotomous-choice and two double dichotomous-choice types were conducted. The respondents in this study appropriately understood the contingent valuation and the suggested price was significant as a characteristic variable. The results imply that there is lower chance to select pork produced by the quality test, as the price difference is greater between conventional and quality-tested pork. WTPs in double and single contingent valuation models were 735 and 547 won/100 g, respectively. WTP was increased with increasing the educational level of respondents. The average WTPs analyzed by convariate were 1,015 won/100 g for double contingent valuation and 580 won/100 g for single contingent valuation. Considering the minimum price of WTP of pork produced by quality test (547.4 won/100 g), the total economic value was estimated to be 5,173,600 million won and per capita customer value was 106,000 won. Therefore, providing an institutional strategy for pork quality test will be beneficial for the consumers.