• Title/Summary/Keyword: production factors

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Studies on the Ecology of Occurrence and Identification of Typhula Snow Mold of Graminous Plants -II. Several Factors Affecting Growth of Typhula incarnata- (화본과식물에 발생하는 설부소입균핵병균(雪腐小粒菌核病菌)의 동정 및 발생상태에 관한 연구 -II. Typhula incarnata의 생육에 미치는 몇 가지 요인-)

  • Kim, Jin-Won;Lee, Du-Hyung;Shim, Gyu-Yul
    • The Korean Journal of Mycology
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    • v.20 no.1
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    • pp.37-43
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    • 1992
  • Typhula incarnata grew over a temperature range of -5 to $20^{\circ}C$ with maximum growth at 10 to $15^{\circ}C$. Sclerotial production for T. incarnata was greatest at the higher temperature. Maximum mycelial growth of this pathogen occurred from pH 5.4 to 6.2. When carbon sources were added to a basal salt medium (Czapek's dox agar) at 5 g carbon sources/l, inulin, soluble starch, galactose, glucose, mannose, manitol, sucrose, maltose, cellobirose, trehalose, raffinose, and dextrin supported growth better than other carbon sources did. Of the twenty-three nitrogen sources tested, glycine, serine, ammonium sulfate, asparagine, asparatic acid, and ${\beta}-alanine$ were the most favorable for mycelial growth of T. incarnata. Cystine and cysteine were poor nitrogen sources. Ammonium salt of nitrogen sources supported growth better than nitrate salt of nitrogen sources. Potato dextrose agar, oat meal agar, and V-8 juice agar were the most favorable for mycelial growth and sclerotial formation. Appropriate addition of pepton to PDA decreased mycelial dry weight, but sucrose supported good growth of T. incarnata. Percent viable sclerotia of T. incarnate buried in bentgrass soil decreased from 2 months after treatment remarkably. Trichoderma riride and bacteria were isolated from non-germinated sclerotia. Live orchard grass leaf pieces within the soil were colonized by T. incarnata better than sterile and unsterile dead leaf pieces at $0^{\circ}C$. Saprophytic ability of T. incarnate on sterile leaf sheath occurred better at $0^{\circ}C$ than at $10^{\circ}C$. Saprophytic microflora consisting of Cladosporium sp., Fusarium sp., Mucor sp., Pythium sp., and unidentified fungi were the competitors for the sterilized and unsterilized substrate, but their colonization was not find on live leaf sheath buried in the soil at $0^{\circ}C$. In the effect of fungicides to Typhula snow mold disease of creeping bentgrass, mixture of polyoxin and thiram was the most effective, followed by iprodione, mixture of iprodione and oxine copper, thiophanate-methyl, myclobutanil, and tolclofos-methyl.

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A Study on the Stiffness of CBA(Corner Block with Anchor Bolt) Joint in Knockdown Type Table Furniture (조립식(組立式) 탁자(卓子)의 CBA접합부(接合部) 강성(剛性)에 관(關)한 연구(硏究))

  • Chung, Woo-Yang;Lee, Phil-Woo
    • Journal of the Korean Wood Science and Technology
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    • v.17 no.2
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    • pp.34-64
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    • 1989
  • Corner block with anchor bolt(CBA) joint method used in knock-down type table furniture manufacturing can reduce the packing and transporting cost. Unfortunately. it also has the disastrous defect to be loosend and unstable during the service life mainly due to fatigue and creep(repeated and prolonged loading). So 22 joint groups constructed were tested to evaluate the effect of some design factors related to the size of side rail(apron). block attachment to side rail. and the number of anchor bolt as well as the effect of the type of corner block(mitered type vs. rectangular type) Usable strength from the stiffness coefficients of each joint group were analysed with SPSS /PC+ and described as the criteria of CBA joint construction. The conclusions were as follows: The height of side rail(50, 75 and 100 mm) and the addition of polyvinyl acetate(PVAc) emulsion in the corner block attactment to side rail had the effect on raising the usable strength of CBA joint with remarkable high significance. And the effect of 2 - anchor bolts was also superior to that of 1 - bolt significantly. However. the thickness of side rail(22 mm vs. 25 mm) had no effect on the strengthening the table joint rigidity. Mitered type corner block joint appeared to he recommendable for CBA jointed table construction rather than the rectangular type one regardless of the method of block attachment to side rail. The best result identified from Duncan's multiple comparison was in the construction with 25 mm thick and 100 mm height of side rail fastened using 2 - anchor bolts in mitered type corner block. But it would be reasonable to use 22 mm thick & 75 mm high side rail and mitered corner block with PVAc emulsion & 2 bolts considering the productivity and production cost down in the MDF furniture manufacturing industries.

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Factors Affecting Wet-Paddy Threshing Performance (탈곡기의 제작동요인이 벼의생탈곡성능에 미치는 영향)

  • 남상일;정창주;류관희
    • Journal of Biosystems Engineering
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    • v.5 no.1
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    • pp.1-14
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    • 1980
  • Threshing operation may be one of the most important processes in the paddy post-production system as far as the grain loss and labor requirement are concerned . head-feeding type threshers commercially available now in Korea originally were developed for threshing dry paddy in the range of 15 to 17 % in wet basis. However, threshing wet-paddy with the grain moisture content above 20 % has been strongly recommended, especially for new high-yielding Indica -type varieties ; (1) to reduce high grain loss incurred due to the handling operations, and (2) to prevent the quantitative and qualitative loss of milled -rice when unthreshed grains are rewetted due to the rainfall. The objective of this study were to investigate the adaptability of both a head-feeding type thresher and a throw-in type thresher to wet-paddy , and to find out the possiblilities of improving the components of these threshers threshing. Four varieties, Suweon 264 and Milyang 24 as Tongil sister line varieties, minehikari and Jinhueng as Japonica-type varieties, were used at the different levels of the moisture content of grains. Both the feed rate and the cylinder speed were varied for each material and each machine. The thresher output quality , composition of tailing return, and separating loss were analyzed from the sampels taken at each treatment. A separate experiment for measurement opf the power requirement of the head-feeding type thresher was also performed. The results are summarized as follows : 1. There was a difference in the thresher output quality between rice varieties. In case of wet-paddy threshing at 550 rpm , grains with branchlet and torn heads for the Suweon 264 were 12 % and 7 % of the total output in weight, respectively, and for the Minehikari 4.5 % and 2 % respectively. In case of dry paddy threshing , those for the Suweon 264 were 8 % and 5% , and for the Minehikari 4% and 1% respectively. However, those for the Milyang 23 , which is highly susceptable to shattering, were much lower with 1 % and 0.5% respectively, regardless of the moisture content of the paddy. Therefore, it is desirable to breed rice varieties of the same physical properties as well as to improve a thresher adaptable to all the varieties. Torn heads, which increased with the moisture content of rall the varieties except the Milyang 23 , decreased as the cylinder speed increased, but grains with branchlet didnt decrease. The damaged kernels increased with the cylinder speed. 3. The thresher output quality was not affected much by the feed rate. But grains with branchlet and torn heads increased slightly with the feed rate for the head-feeding type thresher since higher resistance lowered at the cylinder speed. 4. In order to reduce grains with branchlet and torn heads in wet-paddy threshing , it is desirable to improve the head-feeding type thresher by developing a new type of cylinder which to not give excess impact on kernels or a concave which has differenct sizes of holes at different locations along the cylinder. 5. For the head-feeding type thresher, there was a difference in separating loss between the varieties. At the cylinder speed of 600 rpm the separating losses for the Minehikari and the Suweon 264 were 1.2% and 0.6% respectively. The separating loss of the head-feeding type thresher was not affected by the moisture content of paddy while that of the Mini-aged thresher increased with the moisture content. 6. From the analysis of the tailings return , to appeared that the tailings return mechanism didn't function properly because lots of single grains and rubbishes were unnecessarily returned. 7. Adding a vibrating sieve to the head-feeding type thresher could increase the efficiency of separation. Consequently , the tailing return mechanism would function properly since unnecessary return could be educed greatly. 8. The power required for the head-feeding type thresher was not affected by the moisture content of paddy, but the average power increased linearly with the feed rate. The power also increased with the cylinder speed.

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A Study on the Relationship between Adiponectin, BDNF and Leptin with Abdominal Fat Thickness in Male Workers (남성 근로자의 복부지방두께와 adiponectin, BDNF 및 leptin의 관련성)

  • Ko, Kyung-Sun;Choi, Yoon-Jung
    • Journal of radiological science and technology
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    • v.36 no.3
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    • pp.209-217
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    • 2013
  • Adiponectin (AdipoN), brain-derived nerotrophic factor (BDNF) and leptin (LeP) are mainly secreted from adipose tissue and are known to be involved in regulation of the development of obese. However, there are not many studies on the association between abdominal fat and neuropeptides such as AdipoN, BDNF and LeP. The aim of this study was undertaken to investigate the association between abdominal fat thickness, neuropeptides and cardiovascular disease (CVD) risk factors. The participants in the study were 138 male employees without CVD. This study was approved by the Institutional Review Board of Occupational Safety and Health Research Institute. Written informed consent for the participants in this study was obtained from all individuals. We obtained subcutaneous fat thickness (SFT) and visceral fat thickness (VFT) by using ultrasonography and neuropeptides levels were measured with ELISA kit according to the method suggested by kit manufacturer. The mean SFT and VFT were $1.58{\pm}0.51$ and $4.52{\pm}1.44$ cm. The mean concentrations of AdipoN, BDNF and LeP were $3.14{\pm}3.52$ ng/ml, $24.11{\pm}8.52$ pg/ml and $4.27{\pm}2.38$ ng/ml, respectively. VFT were positively correlated with total cholesterol (r=0.217, p<0.05), LDL-cholesterol (r=0.271, p<0.01), triglyceride (r=0.233, p<0.05) and insulin (r=0.338, p<0.01), but was inversely correlated with HDL-cholesterol (r=-420, p<0.01). AdipoN levels were positively correlated with HDL-cholesterol (r=0.220, p<0.05) and were inversely correlated with total cholesterol (r=-0.196, p<0.05), LDL-cholesterol (r=-0.190, p<0.05), triglyceride (r=-0.199, p<0.05), SFT (r=-0.195, p<0.05) and VFT (r=-0.412, p<0.01). However, LeP levels showed a reverse trend to AdipoN. AdipoN level was significantly higher in non-obese participants (BMI<25 kg/m), but LeP concentration was significantly higher in obese participants (BMI>25 kg/m) than in non-obese. On multiple logistic regression analysis, obese were significantly associated with AdipoN (odds ratio=0.784) and LeP (odds ratio=1.494). These results suggested that AdipoN and LeP concentrations are affected abdominal fat and that dysfunction and/or declination in the production and secretion of neuropeptides might induced ultimately obese and CVD.

The impact of open innovation activities on performance of Korean IT SMEs·Venture: Technology Transfer Experiences and Technological Collaborations (중소·벤처기업의 개방형혁신 노력이 성과에 미치는 영향에 관한 연구: 기술이전경험과 기술협력유형을 중심으로)

  • Roh, Doo-Hwan;Hwang, Kyung-Ho;Park, Ho-Young
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.12 no.1
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    • pp.33-46
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    • 2017
  • In Korea, small and medium sized domestic enterprises (SMEs) play an pivotal role in the national economy, accounting for 99.8% of all enterprises, 87.9% of total employment, and 48.3% of production. and SMEs were driving a real force of the development of national economy in many respects such as innovation, job creation, industrial diversity, balanced regional development. Despite their crucial role in the national development, most of SMEs suffer from a lack of R&D capabilities and equipments as well as funding capacity. Government-Supported Research Institute (GRI) can provide SMEs with valuable supplementary technological knowledges and help them build technological capacities. so, In order to effectively support SMEs, government and GRI must be a priority to know about the factors influencing the performance related to technology transfer and technological collaborations. The paper analyzes the effects of Korean IT SMEs Venture external collaborations and technology transfer on their performances, according to their collaboration activities and technology transfer experiences. The results show that there was a significant difference between '3~5times' of technology transfer experience and 'zero technology transfer experience' in the case of technology transfer experience. In case of technological collaboration type, there was a significant difference between 'R&D manpower' and 'enhancement of technological capabilities including core technologies'. The results show that the effectiveness of technology transfer of Korean IT SMEs Venture depends on experiences, types of collaboration activities. so the results of this research will be useful for Government-Supported research institute (GRI)' policy makers when establishing technology commercialization support policies and strategic planning of small and medium sized domestic enterprises.

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Grain Yield Potential of a Low-Tillering Large Panicle Type in Rice (벼 소얼 수중형 초형의 수량성)

  • Kim, Je-Kyu;B.S., Vergara
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.37 no.4
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    • pp.361-371
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    • 1992
  • For the increase of grain yield potential in rice, a low-tillering large panicled type has been suggested as an ideotype. A low-tillering plant type may have different yield potential and needs different cultural practices from that used in a high-tillering type for the maximum yield. This study was conducted to evaluate the grain yield performances of a low-tillering large panicled rice and high-tillering small panicled rice at different plant spacings, nitrogen(N) levels and seedling numbers per hill. A low-tillering large panicled genotype, IR25588 was compared with a high-tillering small panicled IR58. The grain yield of IR25588 was significantly higher than that of IR58 under a narrow spacing with high N level. The maximum yields of IR58 and IR25588 were reached at about 35,000 and 40,000 spikelets per m$^2$, respectively. The increased grain yield in IR25588 was mainly due to the increase in spikelet number per unit area which is the most precise indicator of grain yield in rice. The optimum spacing for the maximum yield was denser for IR25588 than that for IR58 under high N level. The intra-hill competition of the low-tillering type was lower than that of the high-tillering type. The higher dry matter production and bigger leaf area and culm weight were the main factors for increased grain yield in a low-tillering panicle weight type. Based on the results, the yield potential of a low-tillering panicle weight type was higher than that of a high-tillering panicle number type, especially under a close spacing with high N level.

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Human Embryonic Stem Cell-derived Neuroectodermal Spheres Revealing Neural Precursor Cell Properties (인간 배아줄기세포 유래 신경전구세포의 특성 분석)

  • Han, Hyo-Won;Kim, Jang-Hwan;Kang, Man-Jong;Moon, Seong-Ju;Kang, Yong-Kook;Koo, Deog-Bon;Cho, Yee-Sook
    • Development and Reproduction
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    • v.12 no.1
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    • pp.87-95
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    • 2008
  • Neural stem/precursor derived from pluripotent human embryonic stem cells (hESCs) has considerable therapeutic potential due to their ability to generate various neural cells which can be used in cell-replacement therapies for neurodegenerative diseases. However, production of neural cells from hESCs remains technically very difficult. Understanding neural-tube like rosette characteristic neural precursor cells from hESCs may provide useful information to increase the efficiency of hESC neural differentiation. Generally, neural rosettes were derived from differentiating hEBs in attached culture system, however this is time-consuming and complicated. Here, we examined if neural rosettes could be formed in suspension culture system by bypassing attachment requirement. First, we tested whether the size of hESC clumps affected the formation of human embryonic bodies (hEBs) and neural differentiation. We confirmed that hEBs derived from $500{\times}500\;{\mu}m$ square sized hESC clumps were effectively differentiated into neural lineage than those of the other sizes. To induce the rosette formation, regular size hEBs were derived by incubation of hESC clumps($500{\times}500\;{\mu}m$) in EB medium for 1 wk in a suspended condition on low attachment culture dish and further incubated for additional $1{\sim}2$ wks in neuroectodermal sphere(NES)-culture medium. We observed the neural tube-like rosette structure from hEBs after $7{\sim}10$ days of differentiation. Their identity as a neural precursor cells was assessed by measuring their expressions of neural precursor markers(Vimentin, Nestin, MSI1, MSI2, Prominin-1, Pax6, Sox1, N-cadherin, Otx2, and Tuj1) by RT-PCR and immunofluorescence staining. We also confirmed that neural rosettes could be terminally differentiated into mature neural cell types by additional incubation for $2{\sim}6$ wks with NES medium without growth factors. Neuronal(Tuj1, MAP2, GABA) and glial($S100{\beta}$ and GFAP) markers were highly expressed after $2{\sim}3$ and 4 wks of incubation, respectively. Expression of oligodendrocyte markers O1 and CNPase was significantly increased after $5{\sim}6$ wks of incubation. Our results demonstrate that rosette forming neural precursor cells could be successfully derived from suspension culture system and that will not only help us understand the neural differentiation process of hESCs but also simplify the derivation process of neural precursors from hESCs.

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Studies on LED Wavelength to Enhance Growth and Bio-active Compounds of Carrots (당근의 성장과 생리활성물질 함량을 증진시키는 LED 파장에 관한 연구)

  • Kang, Suna;Kim, Min-Jung;Kim, Bong Soo;Park, Sunmin
    • Journal of Applied Biological Chemistry
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    • v.58 no.2
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    • pp.131-137
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    • 2015
  • Commercial greenhouse plant factories are highly efficient for controlling external factors such as floods, drought, insects, air pollution etc. However, they require substantial startup & maintenance investments and experimental research to optimize production. These facilities are especially useful for urban farming where high efficiency in small spaces is required. In this study, we investigated whether light emitting diode (LED) lights with mixed dominant wavelengths (650 nm : 550 nm : 445 nm=8:1:1, 650 nm : 445 nm=6:4) can increase the growth rate and bio-active compound content of carrots in comparison to that of fluorescent light (FL). LED with mixed wavelength (650 nm : 550 nm : 445 nm=8:1:1) increased the total weight and root circumference of carrots compared to FL. However, ${\beta}$-carotene contents were not significant in LED (650 nm : 550 nm : 445 nm=8:1:1). However, LED (650 nm : 445 nm=6:4) increased the ${\beta}$-carotene (FL: 7.27, LED: 10.48 mg/g ${\beta}$-carotene dried weight). These results suggested that using LED light at the ideal wavelength, at the antithesis color of the plant, might enhance plant growth and bio-active compound contents.

On the field of domestic studies on Western Art History and Western Art Theory (국내 서양미술사, 서양미술이론 연구 장에 관한 연구)

  • Shim, Sang-Yong
    • The Journal of Art Theory & Practice
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    • no.2
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    • pp.75-120
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    • 2004
  • Studies on western art in Korea has been caught in a dilemma that they could deal with only those things which had been arranged according to their 'historical generalization' in their contexts because of the bounds of time and space. It is not trivial that such conditions affect art studies in Korea. Access to the original texts and to their contexts of production is so restricted that the studies on them are prone to he superficial. And it is not independent on the politics of Korean art scene. Such factors are on the background of Korean art's excessive 'assimilation or accordance' with western art. The domestic studies on western art history and art theory have failed to notice the differences in context and Korean art has simply mediated or reproduced the restricted information by those studies. Also the studies on western art in Korea have been made use of as a justifying method of one's own academic domains. In such situations we should lead the studies on western art history and western art theory to a more reflective direction and confirm that the studies should not have any privileges of the realities. And we should try to reform a scholarship which participates in our life and existence. The field of domestic studies on western art history and western art theory should free itself from the invention of objectivity or the neutrality of mechanical reading and turn its eyes to the realities of life where events happens. Constantly suggesting which way Korean art and world art should go has to be the field's new coordinates.

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Analysis of the Utilization Characteristics of Electrical Power and Equipments on the Farms (농촌의 전력및 전기기기의 이용특성분석)

  • 박승우;류한열
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.17 no.4
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    • pp.3943-3955
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    • 1975
  • The purposes of this study are to evaluate the utilization characteristics of electrical power consumption, to grasp the present trends in the use of electrical equipments, to estimate the demand factor and load factor being held, and to evaluate the efficiency of electical uses for the recently electrified farms cultivating paddy rice. For the purposes, 109 sample farms located in eleven villiages electrified in six different years from 1968 to 1973, were chosen at random and investigated on 35 items concerning to electrical uses and wiring systems. The survey was carried out in 1975, in the vinicity of Suweon city. The results are summarized as follows: i) The average annual power consumption on sample farms is considered to be low, being 242.9 Kwh. in 1974, and varied according to the different electrified year and size of cultivated land, respectively. It has significant positive correlation to the area of farm, too. ii) Between the number of year of electrical uses and the power consumption, there is very significant positive correlation, which could be expressed as Y=43.041+16.108 X, where X represents the number of years of electrical uses. The annual increment of power consumption is much greater at the beginning of the electrification than that at the later years, its average being approximately 20 percent. However, it is recommended that any estimation of long-term increments should be carefully investigated. iii) The monthly power consumption varies considerably throughout a year, in which the heaviest farm load occurs in November. Observing the seasonal variation of consumption, the winter-time is the heaviest season while the summer is the lowest. The result implies house lighting is chief contribution to the present electrical consumption on the farms. Comparing the variation of monthly consumption ratios between the sample farms and industries, the electrical uses on the farms are independant of the industrial uses, and further, the agricultural uses are of inverse pattern to the farms from the results that there is negative correlationship between them, iv) The number of electrical equipments used on the farms are occupied chiefly by lighting sources. Next to the lighting sources, household appliances of small quantity and some motors are used. The mean electrical quantity is about 1, 127.4 watt, which corresponds to about 37.6 per cent to the contracted quantity. The composition of quantity is chiefly occupied by the electrical motor of about 1.5 hp., single-phased. The number of the annual utilization hours of each equipment is tabulated in Table IV-5. In contradiction to the high utilization of lighting sources and small household appliances, the motor is poorly used for approximately 22 hours in a year. v) More than 55 per cent of farms want to purchase new electrical equipments such as small household appliances and electrical motors in their number. The impulse of purchasing such items is stimulated by the contacts to the mass media and their knowledge on such equipments. Consequently, the increase of electrical uses could be prompted by such trials as education and demonstration. vi) The demand and load factors on the farms vary considerably according to the greater variation of the power consumption, daily or monthly. The daily demand factor is 22.4 per cent and load factor 18.6 per cent, while the annual demand factor is 1.3 per cent and load factor 70 per cent approximately. Therefore, the low efficiency of construction cost requires re-evaluation of the present contracted quantity of 3 Kw. or increase of electrical uses. vii) The electrical energy on the farms devoted chiefly to lighten the farm residences does not contribute to the farm incomes. Consequently, the cost of electrical consumption presses considerably upon the farm economy. Therefore, there is great need to build up the electrical uses on the farms through the development of new works and techinques to utilize any electrical equipments on the production of farm products. Further more, such the development should be related to increase the actual income of the farm consumers.

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