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Synthesis and Properties of 1,4-Diboracyclohexene-2 Derivatives (1,4-Dibora-2-cyclohexene 유도체들의 합성과 그 성질)

  • Uhm, Jae-Kook;Hu D.;Zenneek U.;Pritzkow H.;Siebert W.
    • Journal of the Korean Chemical Society
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    • v.34 no.5
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    • pp.490-497
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    • 1990
  • Two synthetic routes for the 1,4-diboracyclohexene-2 ring 8 have been developed. Method i) starts with 1,2-bis(dichloroaluminyl)ethane, in which the AlCl$_2$ group is replaced by BCl$_2$. Exchange of the chlorine with BI$_3$ in 1,2-bis-(dichloroboryl)ethane yields the corresponding iodo compound, which reacts with the alkynes to heterocycles 8a, b in good yield. In method ii) B$_2$Cl$_4$ is added to alkenes, replacement of chlorine with BI$_3$ yields the bis(diiodoboryl)ethane derivatives which undergo redox reactions with alkynes to give 8c, d. The diiodo derivative 8a forms the pyridine adduct 9a, and reacts with ether to give the ethoxy derivative 8f. 8a-d react with AlMe$_3$ to yield the corresponding dimethyl derivatives 8g-j, which give unstable radical anions when treated with potassium in THF. The ESR parameters are reported. In electrochemical experiments irreversible reductions of 8g-j are observed. 8g-j react with (C$_5$H$_5$)Co(C$_2$H$_4$)$_2$ to give the intermediate 16 VE complexes (C$_5$H$_5$)Co(8), in which C-H activation occurs with formation of the corresponding red 1,4-diboracyclohexadiene complexes 10. The X-ray structure analyses of 10h and 10j are reported.

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The Urban Spaces and Politics of Hybridity: Repoliticizing the Depoliticized Ethnicity in Los Angeles Koreatown (혼성성의 도시 공간과 정치 : 로스앤젤레스 한인타운에서의 탈정치화된 민족성의 재정치화)

  • Park, Kyong-Hwan
    • Journal of the Korean Geographical Society
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    • v.40 no.5 s.110
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    • pp.473-490
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    • 2005
  • The term hybridity has recently emerged as one of the most popularized leitmotivs in contemporary diasporic and transnational problematics on migrants' nomadic experiences. Especially, in postcolonial politics, hybridity is argued to provide a critical 'third space' on which to challenge discursive boundaries and redescribe power-embedded history However, this paper suggests that the hybrid subject position can be easily articulated in producing new cultural discourse and empowering hegemonic subjects in certain spates. Based on distinguishing the intentional, conscious hybridity from the organic, lived hybridity, this research Intends to investigate the Janus-faced, double-edged nature of the postcolonial politics of hybridity in the case of Los Angeles Koreatown. First, I discuss how a place of organic hybridity in Koreatown can lead to challenging invented and depoliticized ethnicity. At the second half of this paper, 1 focus on understanding the ways in which new Korean American professionals and elites employ the discourse of '1.5 generation' as an intentional hybridity for empowering their own political position at a local scale. I conclusively suggest that hybridity should be a deconstructive strategy to unlearn dominant socio-spatial boundaries rather than bring about the third space as a reterritorialized political position.

Effect of Carbohydrate Source and Cottonseed Meal Level in the Concentrate on Feed Intake, Nutrient Digestibility, Rumen Fermentation and Microbial Protein Synthesis in Swamp Buffaloes

  • Wanapat, Metha;Pilajun, R.;Polyorach, S.;Cherdthong, A.;Khejornsart, P.;Rowlinson, P.
    • Asian-Australasian Journal of Animal Sciences
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    • v.26 no.7
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    • pp.952-960
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    • 2013
  • The objective of this study was to investigate the effect of carbohydrate source and cottonseed meal level in the concentrate on feed intake, nutrient digestibility, rumen fermentation and microbial protein synthesis in swamp buffaloes. Four, 4-yr old rumen fistulated swamp buffaloes were randomly assigned to receive four dietary treatments according to a $2{\times}2$ factorial arrangement in a $4{\times}4$ Latin square design. Factor A was carbohydrate source; cassava chip (CC) and CC+rice bran at a ratio 3:1 (CR3:1), and factor B was level of cottonseed meal (CM); 109 g CP/kg (LCM) and 328 g CP/kg (HCM) in isonitrogenous diets (490 g CP/kg). Buffaloes received urea-treated rice straw ad libitum and supplemented with 5 g concentrate/kg BW. It was found that carbohydrate source did not affect feed intake, nutrient intake, digested nutrients, nutrient digestibility, ammonia nitrogen concentration, fungi and bacterial populations, or microbial protein synthesis (p>0.05). Ruminal pH at 6 h after feeding and the population of protozoa at 4 h after feeding were higher when buffalo were fed with CC than in the CR3:1 treatment (p<0.05). Buffalo fed with HCM had a lower roughage intake, nutrient intake, population of total viable and cellulolytic bacteria and microbial nitrogen supply than the LCM fed group (p<0.05). However, nutrient digestibility, ruminal pH, ammonia concentration, population of protozoa and fungi, and efficiency of microbial protein synthesis were not affected by cottonseed meal levels (p>0.05). Based on this experiment, concentrate with a low level of cottonseed meal could be fed with cassava chips as an energy source in swamp buffalo receiving rice straw.

An Analysis on Preferred Occupation and its Readiness to Students in Dept. of Library & Information Science (문헌정보학 전공자의 선호 직업 및 준비성 실태 분석 연구)

  • Lee, Jong-Moon
    • Journal of Korean Library and Information Science Society
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    • v.40 no.2
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    • pp.473-490
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    • 2009
  • The purpose of this study was to analyze the recognition of those majoring Library & Information Science on the jobs that they can get and want to work for, employment requirements and their preparation, to identify problems and to suggest how to improve current status. To this end, the jobs and employment rate reported by most of the Depts. of Library & Information Science and the preferred jobs and preparation to those majoring library and information were surveyed with 107 students studying in the Dept. of Library & Information Science in the K University as the subjects. According to the results, 49 jobs were identified as the jobs that those majoring Library & Information Science could get into. In the 1st to 20th job ranking groups, 82.1% of all identified jobs, librarian job took lower ranking as 29.2% while other jobs accounted for 52.9%. However, among the jobs from the 1st to 20th ranking accounting for 96% of all jobs that the subjects wanted to have, the librarian job took 45.8% and other jobs 50.6%, which suggested that the preference on librarian job was slightly increased among the jobs that the subjects wanted to have. Furthermore, the employment requirements were classified into religion, language, scholastic achievement, certification and experience. In accordance with investigation on requirements from employment announcement, 92% were in the generally acceptable level or insufficient level. On the basis of such results, it is suggested to introduce a variety of jobs to students and to provide Case-by-Case employment guidance for improvement of employment rate and social capability of students.

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Human Gait-Phase Classification to Control a Lower Extremity Exoskeleton Robot (하지근력증강로봇 제어를 위한 착용자의 보행단계구분)

  • Kim, Hee-Young
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.39B no.7
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    • pp.479-490
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    • 2014
  • A lower extremity exoskeleton is a robot device that attaches to the lower limbs of the human body to augment or assist with the walking ability of the wearer. In order to improve the wearer's walking ability, the robot senses the wearer's walking locomotion and classifies it into a gait-phase state, after which it drives the appropriate robot motions for each state using its actuators. This paper presents a method by which the robot senses the wearer's locomotion along with a novel classification algorithm which classifies the sensed data as a gait-phase state. The robot determines its control mode using this gait-phase information. If erroneous information is delivered, the robot will fail to improve the walking ability or will bring some discomfort to the wearer. Therefore, it is necessary for the algorithm constantly to classify the correct gait-phase information. However, our device for sensing a human's locomotion has very sensitive characteristics sufficient for it to detect small movements. With only simple logic like a threshold-based classification, it is difficult to deliver the correct information continually. In order to overcome this and provide correct information in a timely manner, a probabilistic gait-phase classification algorithm is proposed. Experimental results demonstrate that the proposed algorithm offers excellent accuracy.

The Survey on the Drug use status, Knowledge and Attitude of College Students (Seoul and Northern Part of the Kyunggi-do) (대학생의 약물 사용 실태.지식 및 태도(서울 및 경기 북부지역))

  • Han, Kyoung-Soon;Moon, Sun-Young;Park, Hyun-Ok;Park, Eun-Hee
    • The Journal of Korean Academic Society of Nursing Education
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    • v.6 no.2
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    • pp.376-389
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    • 2000
  • The Purpose of this study was to grasp the status of drug uses in college students, and to investigate the knowledge and attitude when they use it. We collected through questionnaires from Sep. 1 to Oct. 30 in 1999. The subjects were 490 college students in Seoul and northern of the Kyunggi-do. The data analysis was performed using SPSS (version 7.0) and ANOVA. The results of this study were as follows. 1. There was no correlation for all factors in the relationship between general characteristics of subjects and knowledge for drugs. On the contrary, in the relation of the general characteristics and attitude for drug of subjects, some factors are statistically significant e.g., department (F=3.049, p<.010), satisfaction for school life (F=6.167,p<.002), body shape(F=8.092, p<.000), and the relationship with ones parents (F=3.728, p<.005). 2. In the analysis of drug use status and knowledge, only in the factor of administration control was statistically significant(F=4.304, p<.014) and in the relation of attitude for drug uses, drug administration was statistically significant (F=4.521, p<.004). 3. In the mean scores for the drug knowledge analysis, the highest factor was 'A narcotic make deformed persons through poisoning of physical and mental' (M=4.14), the lowest factor was 'If catch the flu during the pregnancy, should be take drug as possible as quickly to reduce negative effect for fetal' (M=1.94). 4. In the analysis for drug attitude, the highest factor was 'A drug is alike a poison' (M=3.48), 'Should be keep the usage and dosage of drug' was the lowest (M=1.48). 5. From the investigation for status of drug use, it was revealed that the most subjects (73.6%) were purchase drugs after explain their symptoms to pharmacist. And they take drugs only when they felt painful in 43.1%. The most students (70.4%) were experienced control of drug administration. It was inquired that subjects were mainly obtained information about drugs from pharmacist and television (or radio) advertisement, 33.5% and 33.1%, respectively. In the examination for existence of long-term administrators in their family, 'none' and 'only parents' are 49.6% and 37.3%, respectively. When their parents have illness, the persons go to drugstore and hospital for heath-care, 47.8% and 44.3%, respectively. On the basis of results of this study, we suggest as follows. 1. This study was analyzed data from questionnaires for college students in a part of local areas, so we suggest that the next research should be perform for national-wide students as subjects to generalize the results. 2. It is need more intensive research methodologies such as interview and observation. 3. Additional research is required for knowledge and behaviors of drug uses that will how impact on ones health behavior.

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Performance Evaluation of Karan Fries and Karan Swiss Cattle under Closed Breeding System

  • Singh, M.K.;Gurnani, M.
    • Asian-Australasian Journal of Animal Sciences
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    • v.17 no.1
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    • pp.1-6
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    • 2004
  • The 490 and 380 performance records of Karan Fries and Karan Swiss cows developed through crossbreeding followed by inter-se mating were evaluated for production, reproduction performance and disposal rate. Duration of study (1982-92) was grouped into five periods (1982-83; 1984-85; 1986-87; 1988-89; 1990-92) and each year was divided into four seasons (Winter: Dec.-Jan.; Spring: Feb.-March; Summer: April-June; Rainy: July-Sept.; Autumn: Oct.-Nov). Data were also classified according to sire and level of inbreeding. The least squares means of FLY (first lactation yield -305 days), FLL (first lactation length), FSP (first service period), FDP (first dry period), FCI (first calving interval ), MY/FLL (milk yield per day of first lactation length), MY/FCI (milk yield per day of first calving interval), EBV (expected breeding value) and EBE (expected breeding efficiency) were $3,173{\pm}82$ kg, $34611{\pm}$days, $143{\pm}11$ days, $75{\pm}6$ days, $423{\pm}11$ days, $10.6{\pm}0.2$ kg, $8.9{\pm}0.2$ kg, $3,380{\pm}26$ kg, and $88.2{\pm}1.3$% respectively in Karan Fries. Corresponding estimates in Karan Swiss cows were $2,616{\pm}82$ kg, $328{\pm}8$ days, $148{\pm}12$ days, $103{\pm}9$ days, $435{\pm}13$ days, $8.9{\pm}0.2$ kg, $7.2{\pm}0.3$ kg, $2,924{\pm38}$ kg and $86.0{\pm}3.8$% respectively. The effect of sire was significant on FLY, MY/FLL, MY/FCI and EBV in both the herd (p<0.01). The 10 and 15% sires showed superiority (FLY) over herd average of 11 and 7% in Karan Fries and 32 and 21% in Karan Swiss cattle respectively. Inbreeding has adversely and significantly (p<0.05) affected the FLY, MY/FLL, MY/FCI and survivability of Karan Fries females; FDP and disposal through culling of Karan Swiss heifers. The Karan Fries heifers with inbreeding above 12.5% performed 16% lower FLY to herd average. The effect of season of calving was significant on FLL, FSP and FCI (p<0.05) in Karan Fries. Summer calvers ($361{\pm}12$) were have higher lactation length and autumn calvers ($329{\pm}14$) had minimum. Period of calving significantly influenced the FSP, FCI, MY/FLL and MY/FCI in Karan Fries and FLY, MY/FLL and MY/FCI in Karan Swiss. Production efficiency traits in Karan Fries herd witnessed higher yield in the last two periods whereas, Karan Swiss heifers showed fluctuating performance. The findings suggested judicious use of available genetic variability, keeping of inbreeding under safer level and managemental interventions for the consistent improvement of both herds.

Anaerobic Digestion of Fish Offal(II) : Evaluation of Biodegradability Using Biochemical Methane Potential (생선 폐기물의 혐기성 소화 처리(II) : Biochemical Methane Potential을 이용한 생분해도 평가)

  • Jeong Byung-Gon
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.9 no.3
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    • pp.154-159
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    • 2006
  • It is essential to understand the decomposition characteristics for developing the optimum anaerobic digestion system of organic wastes. In this study, BMP (Biochemical Methane Potential) test using serum bottle was conducted to evaluate the anaerobic degradability of fish offal. 3 different groups of fish offal including waste from mackerel and hairtail handling except viscera and fish viscera were chosen for the substrates. Grinded fish offal was transferred anaerobically to serum bottle in amounts of 50 ml, 100 ml and 150 ml, respectively. BMP test was carried out in triplicate. Cumulative methane production and methane production rate depending on incubation time were evaluated. These results varied depending on substrate characteristics. The average values of ultimate methane yield ranged between $420ml{\cdot}CH_4/g{\cdot}VS$ and $490ml{\cdot}CH_4/g{\cdot}VS$, and the methane production and degradation rate of viscera were higher than those of other parts of fish offal. According to the analysis of elemental composition, average C/N ratio of fish offal used in this study was 5.2. Theoretical ultimate methane yield calculated from elemental composition was $522ml{\cdot}CH_4/g{\cdot}VS$. Biodegradability was calculated as 0.847.

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Human Engineering Approach to the Standardization of Shelving, Chairs, Tables and Card Cabinets for College and University Libraries In Korea (한국 대학도서관 가구의 표준화에 관한 인간공학적 연구 -서가${\cdot}$의자${\cdot}$책상${\cdot}$ 목록함을 중심으로-)

  • Sohn Jung Pyo
    • Journal of the Korean Society for Library and Information Science
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    • v.11
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    • pp.3-42
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    • 1984
  • This is to establish a model of the standardization of shelving, chairs, tables and card cabinets for college and university libraries in Korea. The size of furniture was measured on the base of the analysis of the human factors, such as the standard size of human bodies of the college students in Korea, the scope of work area, the moving degree of muscles, the limit of the visual field, etc. The results of this study are as follows: 1. It is desirable that the standard shelf length should be 800mm. and the maximum . shelving height should not exceed 1,803mm. And it is desirable that the bottom shelf has a ground clearance of about $210\~390mm$. 2. It is advisable that the sloped shelving has the slope from about 1,000mm, or 930mm, and the gradient should be $19^{\circ}$ from the above mentioned sloping position and the bottom of each shelf. And it is desirable that the slope height of each shelf should be 77mm. 3. It is advisable that the seat area for users should be $410\~420\times420mm$, and the seat height should be $390\~0400mm$. 4. It is desirable that the table size per user should exceed $490\times880\~890mm$, and the table height should be $680\~690mm$. 5. It is advisable that each tray of the card cabinet should hold about 740 cards, and the depth should exceed 430mm. And it is desirable that the maximum height of card cabinets should be as follows: 60du(drawer units)-$1,400\~1,460mm$, 30du-1, 300mm, 15du-1,100mm. In addition, it is advisable that the 30du cabinet should accomodate 5 trays vertically and 6 trays horizontally for avoiding the worst working position rather than 6 trays vertically and 5 trays horizontally. 6. It is desirable that the height of sliding reference shelves in card cabinets, or consultation tables should be 900mm. But in the case of the sliding shelves, it is desirable to be as follows: 15du-900mm when the card cabinet height is more than 1,100, mm, but unnecessary when less than 1,100mm high, 30du-1,000mm, or 1,100mm in the case of $5\times6du$, but 900mm in the case of $6\times5du$, $60du-900\~950mm$ when the card cabinet height is $1,400\~1,460mm$.

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Reason and Prevention of Color Reversion of Corn Oil in Summer (옥수수기름의 하절기 변색현상 원인규명 및 방지대책)

  • Koo Bon-Soon
    • Food Science and Preservation
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    • v.11 no.4
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    • pp.485-490
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    • 2004
  • Crude corn oil (CCO) was obtained through the expression-extraction process from corn germ. The CCOs of final process at $90^{\circ}C,\;70^{\circ}C\;and\;50^{\circ}C$ were stored in outdoor storage tanks. From the samples, refined CCO (RCCO) were prepared with $0\%,\;10\%\;and\;20\%$ excessive of phosphoric acid, caustic solution and acidic clay were used in degumming-alkali refining-bleaching process. RCCOs were stored at room temperature in dark places. The color change was not effected by the amount of phosphoric acid, caustic solution and acidic clay, but temperature of process affects the color change. Finally, the prevention for color reversion of RCCO could be obtained by lowering the temperature of final process and optimal temperature of RCCO in summer was found about less than $50^{\circ}C$.