• Title/Summary/Keyword: theory theory

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The Relationships between Dry Matter Yield and Days of Summer Depression in different Regions with Mixed Pasture (혼파초지에서 지역별 건물수량과 하고일수 간 관계)

  • Oh, Seung Min;Kim, Moonju;Peng, Jinglun;Lee, Bae Hun;Kim, Ji Yung;Chemere, Befekadu;Kim, Si Chul;Kim, Kyeong Dae;Kim, Byong Wan;Jo, Mu Hwan;Sung, Kyung Il
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.38 no.1
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    • pp.53-60
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    • 2018
  • Yield prediction model for mixed pasture was developed with a shortage that the relationship between dry matter yield (DMY) and days of summer depression (DSD) was not properly reflected in the model in the previous research. Therefore, this study was designed to eliminate the data of the regions with distinctly different climatic conditions and then investigate their relationships DMY and DSD using the data in each region separately of regions with distinct climatic characteristics and classify the data based on regions for further analysis based on the previous mixed pasture prediction model. The data set used in the research kept 582 data points from 11 regions and 41 mixed pasture types. The relationship between DMY and DSD in each region were analyzed through scatter plot, correlation analysis and multiple regression analysis in each region separately. In the statistical analysis, DMY was taken as the response variable and 5 climatic variables including DSD were taken as explanatory variables. The results of scatter plot showed that negative correlations between DMY and DSD were observed in 7 out of 9 regions. Therefore, it was confirmed that analyzing the relationship between DMY and DSD based on each region is necessary and 5 regions were selected (Hwaseong, Suwon, Daejeon, Siheung and Gwangju) since the data size in these regions is large enough to perform the further statistical analysis based on large sample approximation theory. Correlation analysis showed that negative correlations were found between DMY and DSD in 3 (Hwaseong, Suwon and Siheung) out of the 5 regions, meanwhile the negative relationship in Hwaseong was confirmed through multiple regression analysis. Therefore, it was concluded that the interpretability of the yield prediction model for mixed pasture could be improved based on constructing the models using the data from each region separately instead of using the pooled data from different regions.

Study on Measuring the Value of Recreational Forests Using Contingent Valuation Method (조건부가치측정법을 이용한 자연휴양림 휴양가치 측정)

  • Kang, Kee-Rae
    • Journal of the Korean Institute of Landscape Architecture
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    • v.37 no.5
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    • pp.42-52
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    • 2009
  • Recreational forests are catching on as places for personal development through recreation, association with people, education about nature, mind relaxation and spiritual peace. However, the value and significance of recreational forests with various functions are easily overlooked. Whoever pays fees for admission to facilities are able to enjoy fresh air, a comfortable environment, and space for rest. It should be taken into consideration whether the fee which customers pay is appropriate for the value of nature they are enjoying. This study is involved in giving the right recognition to the value of recreation and environment by estimating economically the value of the environment in which visitors stay, and presenting the appropriate price. The most efficient way to achieve this goal is through an economic approach, which suggests following established research skills and yielding suitable and accurate amounts of money. The environmental value of a recreational forests is estimated through contingent valuation method(CVM), which is chosen among several methods to estimate public facilities because the value of recreational forests has strong characteristics as public facilities which are not traded in the market. The annual recreation value per person of surveyed recreational forests is Willingness To Pay(WTP) with a mean between about 16,000 won and 25,400 won. The recreation value of one recreational forest surveyed is annually between approximately 1.7 billions won and 2.7 billions won. The annual recreation value of 85 national and public recreational forests is presumed to be between about 140 billions won and 230 billions won. The presumed amount of money is the environment in which visitors can enjoy whenever they invest some money and time. Indeed, it is more than that; it provides visitors with a greater sense of satisfaction and the recognition of the preciousness of nature and the environment.

The Effect of Cold Shock on Function and Morphology of Dog Epididymal Spermatozoa (개에서 cold shock이 정소상체유래의 정자의 기능과 형태에 미치는 영향)

  • Yu Il-jeoung
    • Journal of Veterinary Clinics
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    • v.21 no.4
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    • pp.329-335
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    • 2004
  • Dog spermatozoa were recovered from the caudae epididymides of 23 domestic dogs which were 11 pure breed and 12 mix-breed dogs ranging in age from 0.6 to 3 years. The experimental designs were as follows: 1) the effect of chilling to 0. 10 or 37$^{\circ}C$. 2) the kinetics of chilling injury at 0 or 4$^{\circ}C$, and 3) the effect of sugars at $0^{\circ}C$. Viable spermatozoa were recovered by percoll gradient separation and adjusted to 5${\times}$10$^{7}$ spermatozoa/ml. In experiment 1, spermatozoa were diluted with 0.33 M glucose supplemented with 3% BSA (G-BSA) at 1:2 dilution. Spermatozoa were loaded into straws and exposed at 0, 10 or 37$^{\circ}C$ for 30 min. In experiment 2, spermatozoa were prepared as the experiment 1 and exposed for 0.5, 5, 15, or 30 min at 0 or 4$^{\circ}C$. In experiment 3, spermatozoa were diluted with different sugars (0.33 M galactose, glucose, fructose, mannitol, lactose, sucrose, raffinose) and cooled to $0^{\circ}C$ for 30 min. Sperm membrane integrity, motility and acrosome integrity were assayed after rewarming at 37$^{\circ}C$ for 5 min. Sperm motility and membrane integrity abruptly decreased with decreasing temperature but acrosome integrity gradually decreased (P<0.05). Sperm motility was more sensitive to cold shock than membrane integrity and acrosome integrity. Spermatozoa cooled to $0^{\circ}C$ were more damaged than those at 4$^{\circ}C$. Sperm motility was not different among exposed times at both. 0 and 4$^{\circ}C$. However, membrane integrity of spermatozoa exposed for 30 min at both 0 and 4$^{\circ}C$ was significantly lower (P<0.05). Spermatozoa diluted in 0.33 M fructose or galactose showed lower motility and higher morphological abnormality with coiled tail at $0^{\circ}C$. These sperm characteristics were strongly related. These results indicate that dog epididymal spermatozoa are relatively sensitive to rapid cooling and higher morphological abnormality at $0^{\circ}C$ was shown in spermatozoa diluted in fructose and galactose.

The Future Prospect of the Studies on the Objectification of Sasang Constitution (사상체질진단(四象體質診斷)의 객관화(客觀化) 연구(硏究)에 대한 현황(現況) 및 전망(展望))

  • Song, Il-byung
    • Journal of Sasang Constitutional Medicine
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    • v.10 no.1
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    • pp.1-11
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    • 1998
  • Constitution means to combine the function into the body. It also includes the genetic factor and the environmental factor. Sasang Constitutional Medicine has the organized and unique ideas of the theory and the practice. So it is widly used in korea. But It has a problem to be popular. That's the objectification of Sasang constitution. There are so many studies to classify Sasang constitution analytic and objectively. I try to classify the studies to identify Sasang constitution objectively and check the problems. 1. The morphologic studies of Sasang Constitution are dividied into the figure and the face-speech through the morphologics and the phonetics. We need to standardize and make a simple method through computer software. 2. The study of the mind is used by the questionnaire about the telent, the character, and the greed each constitution. Recently QSCC II computer software is made and is used at many clinics in Korea. We need to recheck children and Taeyangin. 3. The symptom and the disease are subjective. So the study of them is usually used by some diagnostic equipments. But these have to be revaluated on the view of Oriental Medicine and Sasang Constitutional Medicine and try to study the objectification of Sasang constitution. And then we must try to objectify Sasang constitutional disease. 4. Disease and symptoms have to be studied much more about the mechanism and the relation. The study of medicine was done the way of the homeopathy using EAV. But that had some problems. So it should depend on the new science.

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A Study on the Effectiveness and Possibility of General Chemistry Experiment Lecture with Flipped Classroom (거꾸로 교실을 적용한 일반화학실험 강좌의 효과 및 가능성 탐색 연구)

  • Yoon, Jihyun;Son, E Nok;Kang, Seong-Joo
    • Journal of the Korean Chemical Society
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    • v.62 no.2
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    • pp.124-136
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    • 2018
  • In this study, we applied the flipped-classroom to the general chemistry experiment lecture of the domestic university with strong teacher-led, and explored the effects and possibilities of the course. For this purpose, 30 students who were enrolled in the Science Education Department of the College of Education in the metropolitan area were randomly assigned to two groups, namely, the flipped-classroom group and the traditional class group. Then, we developed a general chemistry experiment lessons based on the flipped-classroom along with visual materials and we applied the lessons for 15 weeks. After all the classes, we conducted a survey to see the students' perception of the general chemistry experiment lecture by flipped classroom. As a result of analysis, the students of the flipped-classroom group were more positive than the students of the traditional class group in terms of the usefulness of the class activity, the importance of each activity element for the successful learning, the learning level, and the intention for another lesson. As a result of analyzing students' perceptions in terms of general chemical experiment activities such as conducting experiments or writing reports and understanding the contents of experiments, the average score of the flippedclassroom group was higher than the traditional class group, and the main cause of this result was the video material provided by prior learning activities. In addition, as a result of analyzing students' perceptions in terms of interactions and self-directed learning in class, the average score of the flipped-classroom group was generally higher than the traditional class group. In particular, students' interactions and self-directed learning were statistically significant differences between the two groups. And the students' perception of video material was very positive, and it was analyzed that the video that the instructor directly explained experiment theory and method was the most favorite videos of students. We discussed educational implications of these findings.

Determination of Reactivities by Molecular Orbital Theory (V). Sigma Molecular Orbital Treatment of $S_N$ Reactivities of Alkylchlorides. (화학반응성의 분자궤도론적 연구 (제5보). 염화알킬의 친핵성치환 반응성에 대한 시그마 분자궤도론적 연구)

  • Ikchoon Lee;Bon-Su Lee;Kwang-Su Kim
    • Journal of the Korean Chemical Society
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    • v.17 no.2
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    • pp.95-104
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    • 1973
  • Ground electronic structures and SNreactivities of a series of alkylchlorides (methyl,ethyl, iso-propyl, trans n-butyl, sec-butyl, tert-butylchloride) have been studied using approximate $({\sigma}-MO)$ method, such as EHT and CNDO/2. It was found that CNDO/2 gives better results for the systems such as alkylchlorides whose structural differences are not remarkable, in comparison with EHT method. According to CNDO/2 results, calculated dipole moments for alkylchlorides are slightly higher than observed values, showing the order of primary < secondary < tertiary alkylchlorides. It was also found that highest occupied(HO) MO's are completely or nearly degenerate, and show relatively weak $\pi$-antibonding nature between$\alpha$-carbon and Cl atoms. Furthermore, the electrons in this MO are largely confined to Cl atom, and hence these behaves as likely as p-lone pair electrons of Cl atom. On the contrary, lowest unoccupied (LU) MO's show strong $\sigma$-antibonding nature between $\alpha$-carbon and Cl atoms whose electron clouds are directed along the C-Cl axis. It has been discussed that the$S_N2$ reactivities of alkylchlorides may largely be controlled by ${\sigma}^{\ast}$ LUMO, and the antibonding strength between $\alpha$-carbon and Cl atoms in this MO may become the measure of $S_N2$reactivity. The relationship between $S_N2$reactivity and C-Cl bond polarizability has also been discussed. It has been suggested that the unique structure factors determining $S_N1$reactivities may be $\pi$-antibonding strength between $\alpha$-carbon and Cl atoms in HOMO and C-Cl bond strength in ground state.

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Bond Orbital Theory of Chemical Reactivity (反應性의 結合 Orbital 理論)

  • Yang, Kang;Ree, Tai-Kyue
    • Journal of the Korean Chemical Society
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    • v.8 no.1
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    • pp.20-24
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    • 1964
  • The linear combination of bond orbitals method is used to investigate the reactivity of halomethanes in abstraction reactions by atoms. The activation energy is evaluated on the assumption that, in an activated complex, two electrons in a bond to be broken become completely isolated from the rest of the ${\sigma}$-electron systems. Such a model leads to an intuitively attractive concept that the interactions between the reactive bond and the neighboring bonds govern the reactivity of ${\sigma}$-electron systems. The resulting equation for the activation energy, ${\varepsilon},\;is:\;{\narepsilon}= ${\varepsilon}={\zeta}+$$${\sum}_{i=1}^3$${\eta}c-I,$ c-4 Here, subscript C-4 indicates the bond to be broken, while C-i represents the other three bonds surrounding the reactive bond; ξ is the activation energy of a hypothetical reaction of an isolated C-4 bond and an attacking atom; and ${\eta}$C-i,C-4 stems from the stabilizing interacting of C-4 bond with neighboring C-i bonds. A choie of η′s consistent with bond strength data simplifies the above equation to a form ${\varepsilon}={\zeta}\;+\;N{\eta}c$-H, C-4 where N denotes the number of C-H plus C-F bond in halomethanes. In agreement with this equation, experimental -values increase linearly with increasing N.

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Removal of Red Tide Organisms -1. flocculation of Red Tide Organisms by Using IOSP- (적조생물의 구제 -1. IOSP에 의한 적조생물의 응집제거-)

  • KIM Sung-Jae;CHO Kyu-Dae
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.33 no.5
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    • pp.448-454
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    • 2000
  • This study was to examine the physicochemical characteristics of coagulation reaction between ignited oyster shell powder (IOSP) and red tide organisms (RTO), and its feasibility, in developing a technology for the removal of RTO bloom in coastal sea,IOSP was made from oyster shell and its physicochemical characteristics were examined for particle size distribution, surface characteristic by scanning electron microscope, zeta potential, and alkalinity and pH variations in sea water. Two kinds of RTO that were used in this study, Cylindrotheca closterium and Skeletonema costatum, were sampled in Masan bay and were cultured in laboratory. Coagulation experiments were conducted using various c(Incentrations of IOSP, RTO, and a jar tester. The supernatant and RTO culture solution were analyzed for pH, alkalinity, RTO cell number, IOSP showed positive zeta potentials of $11.1{\~}50.1\;mV\;at\;pH\;6.2{\~}12.7$, A positive zeta potential of IOSP slowly decreased with decreasing pNa 4,0 to 2,0. When pNa reached zero, the zeta potential approached zero, When a pMg value was decreased, the positive zeta potential of IOSP increased until pMg 3.0 and decreased below pMg 3.0. IOSP showed 4.8 mV of positive zeta potential while RTO showed -9.2 mV of negative zeta potential in sea water. A positive-negative EDL (electrical double-layer) interaction occurred between $Mg(OH)_2$ adsorption layer of IOSP and RTO in sea water so that EDL attractive force always worked between them. Hence, their coagulation reaction occurred at primary minimum on which an extreme attractive force acted because of charge neutralization by $Mg(OH)_2$ adsorption layer of IOSP. As a result, the coagulation reaction was rapidly processed and was irreversible according to DLVO (Deriaguin-Landau-Verwey-Overbeek) theory. Removal rates of RTO were exponentially increased with increasing both IOSP concentration and G-value. The removal rates were steeply increased until 50 mg/l of IOSP and reached $100{\%}\;at\;400\;mg/l$ of IOSP. Removal rates of RTO were $70.5,\;70.5,\;81.7,\;85.3{\%}$ for G-values of $1,\;6,\;29,\;139\;sec^(-1)$at IOSP 100 mg/l, respectively. This indicated that mixing (i.e., collision among particles) was very important for a coagulation reaction.

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A Study on the Characteristics of Descriptions of the Perspiration in "Hwangjenaegyeong(黃帝內經)" (황제내경(黃帝內經)에 보이는 한(汗)관련 서술(敍述)의 특징(特徵)에 대한 고찰(考察))

  • Lyu, Jeong-Ah;Jang, Woo-Chang;Baik, You-Sang;Jeong, Chang-Hyun
    • Journal of Korean Medical classics
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    • v.23 no.2
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    • pp.205-223
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    • 2010
  • In Korean Traditional Medicine(abbreviated to K.T.M.), hyperhidrosis and anhidrosis are the targets of the medical treatment. Furthermore sweating appearance is also one of the important symptoms which explain a particular situation of the patient in K.T.M. And at "Sanghanron(傷寒論)" which is a traditional chief clinical bible written by Jang Gi(張機) later Han dynasty(漢代) in China made full use of the various kinds of diaphoresis[汗法] as a main medical treatment with purgation therapy[下法] and emetic therapy[吐法]. So the sweat in itself not only is the disease, but also is one of the symptoms explain a disease pattern. This thesis inquires into "Hwangjenaegyeong(黃帝內經)" referring to sweat which is the origin of recognition to the sweat in K.T.M. Some theses similar to this research had been made progresses and already reported, but most of them have classified the contents into biology, pathology, diagnosis, treatment after the model of western medical theory. In the aspect of comparative studying with other literature and clinic practical using, we found characteristics of referring to sweat in "Hwangjenaegyeong(黃帝內經)". And we classify the characteristics into some categories as follows. 1. There are some terms which make a title including sweat and symbolize the characteristics, for example sweat of soul[魄汗], sweat of death[絶汗], sweat of streaming[灌汗], sweat of weakness[白汗], sweat of sleep[寢汗], sweat of bright and heat[炅汗], sweat of kidney[腎汗], sweat of escaping[漉汗], cold sweat[寒汗], sweat on the head[頭汗], hyperhidrosis[多汗], heavy sweat[大汗]. But there aren't spontaneous sweat[自汗] or sweat like a thief[盜汗] which are the normal terms referring to sweat in history of K.T.M. And there are several descriptions about sweat appearance such as sweating in half of body[汗出偏沮], sweating in the rear end and thigh and knee[汗出尻陰股膝], hyperhidrosis in the neck and aversion to wind[頸多汗惡風], hyperhidrosis in the head and face and aversion to wind[頭面多汗惡風], cannot stopping the sweating under head[頭以下汗出不可止], make a person sweat to one's feet[令汗出至足], sweating like escaping[漯漯然汗出], sweating like soaking[汗出如浴], sweating become moist[汗出溱溱], hardly escaping sweat[汗大泄], escaping sweating[漉漉之汗], sweat moisten the pores [汗濡玄府], ceaseless sweating like pouring[汗注不休] sweating like pouring and vexation[汗注煩心], damp with sweat[汗汗然], sweating spontaneously[汗且自出], removal of fever with sweat drying[熱去汗稀]. That can be divided into sweat region and sweat form. 2. There are detailed explanations of the principle of perspirations caused by hot weather, hot food, hard working and meeting damp pathogen. 3. There are some explanations of the principle of removing fever due to the excessive heat from internal and external body through sweating by replenishing the body fluid. And many descriptions about overcoming the febrile disease by dropping temperature through sweating and many diaphoresis for curing. 4. There are some descriptions about five Jang organs perspirations and attachment of five mucous body fluid to five Jang organs. 5. There are pathogenic progresses after sweating affected by the Six Atmospheric Influences and water. And detailed explanations of disease mechanism a sweat leading to another disease. 6. There are descriptions about various sweat absent situations.

Reliability Analysis on Firewater Supply Facilities based on the Probability Theory with Considering Common Cause Failures (소방수 공급설비에 대한 공통원인고장을 고려한 확률론적 신뢰도 분석)

  • Ko, Jae-Sun;Kim, Hyo
    • Fire Science and Engineering
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    • v.17 no.4
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    • pp.76-85
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    • 2003
  • In this study, we write down the definitions, their causes and the techniques of analysis as a theoretical consideration of common cause failures, and investigate the limitation and the importance of the common cause failures by applying to the analysis on the fire protection as a representative safety facility. As you can know in the reliability analysis, most impressive cause is the malfunctions of pumping operations; especially the common cause failure of two pumps is dominant. In other words, it is possible to assess system-reliability as twice as actual without CCF From these, CCF is extraordinarily important and the results are highly dependent on the CCF factor. And although it would increase with multiple installations, the reliability are not defined as linear with those multiplications. In addition, the differences in results due to the models for analysis are not significant, whereas the various sources of data produce highly different results. Therefore, we conclude that the reliabilities are dependent on the quality of the usable data much better than the variety of models. As a result, the basic and engineering device for the preventions of CCF of the multiple facilities is to design it as reliably as to design the fire-water pump. That is to say, we must assess those reliabilities using PFD whether they are appropriate to SIL (Safety Integrity Level) which is required for the reliability in SIS (Safety Instrumented System). The result of the analysis on the reliability of the fire-water supply with CCF shows that PFD is 3.80E-3, so that it cannot be said to be designed as safely as in the level of SIL5. However, without CCF, PFD is 1.82E-3 which means that they are designed as unsafely as before.