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李麗夏,鄭燦吉 建國大學校附設 農業資源開發硏究所 1980 論文集 Vol.5 No.-
1. The Korean Government has put massive effort to protect and reforest the mountains since her independence in 1945. Without adequate alternative means of fuel supplies, however, farmers and firewood dealers could not help stop illegal cutting of the forest woods. Recognizing the necessity of alternative ways of fuel supplies the Government started to establish 850 thousands hectars of fuelwood plantations in 1959 with an aim to arrange farm fuels through the establishment of fuel forests, contributing to the prevention of forest demages. The program was accomplished in 1977, totalling 643 thousand hectars planted in terms of area which is less than as planned by 207 thousand hectare,after many years of trial and errors. Of 643 thousand hectare of the fuelwood establishment, 50 thousand hectares were carried out in 1976,and 127 thousand hectare in 1977 respectively. Part of the necessary funds for the project was provided by IBRD loaning during 1976 and 1977 years. Shape of forest is visibly improving in re cent years. 2. The present status of the Village Forestry association system as of the end of October, 1977 is that a total mambers of the VFA are amounted to 2,250,000. There are more 21,109 VFA and there associations organize 141 City and County Forestry Association Unions, these organizations resemble the administrative organization system and become to have cooperation and connection with administrative system. 3. The total number of households of the 36 sample Villages was 4,085. Average number of households per village was 113. Average family number per household was 5.7 person which was very high. Of the total households 3,624 households were farm households and the rest nonfarm households. This comprises the ratio of 89 percent for the farm households and 11 percent for the non-farm households. Relatively high ratio of the farm households indicates that rural households in Korea are heavily dependent upon farming. Members of Village Forestry Association were 3,839 which amount to 93 percent of the total household surveyed. Of the total VFA member households, 916 households were forest land owners and 2,741 households did not possess their own forest land. 4. A total land area of the sample Villages was 19,789,871 hectare consisting of 4,323 hectare of cultivation land 2,936 hectare of upland, and 10,807 hectare of forest land. An average land area per Village was about 300 hectare. 5. Of 10,807 hectare of the forest land the share of fuelwood plantation was 2,962 hactare which amounts to 27.4 percent of the total forest land of the sample villages. Of the tota plantation area 1,877 hectare which amounts to 631.4 percent was established before 1976 and 1,084 hectare which is 36.6 persent was planted since 1973. 611.6 hectare which amounts to 20.6 percent of the total fuelwood plantation was established during 1976 and 1977 with IBRD loans. Amount 20 percent of the fuelwood plantation area which was established before 1973 was disused and considered to result in a great waste of resources. 6. Varieties of the fuelwood species are regidar pine, acasia, alter, acasia-alter mixed forest and bush clover. The most preferable species among VFA members was rigidar pine due to its strong adaptability to environment and fast growth. Looking at the fuelwood plantation area established before 1973 by fuelwood species acasia amounted to 38.4 percent rigidar pine 50.7 percent, alder 6 percent,and other 41.8 percent. Of 190 hectares planted in 1974 acasia amounted to 33 percent, rigidar pine 36 percent, alder 17 percent, and bush clover 5 percent. Of 204 hectare established in 1975 acasia was 36 percent, rigidar pine 21 percent, alder 34.7 percent, and bush clover 7.8 percent. Of 290 hectare planted in 1976 acasia amounted to 23.3 percent, rigidar pine 40.4 percent, alder 26.9 perpent, bush clover 2.8 percent, and other 6.5 perpent. Of 374 hectare planted 1977 acasia amounted to 22.4 percent, rigidar pine 41.8 percent, alder 15.7 percent, bush clover 15.2 percent, and other 4.9 percent. According to the figures the rigidar pine has the largest planted area except 1975. On the basis of the percentage of the plantation area the rankings among fuelwood species are rigidar pine, alder, acasia, and bush clover. 7. Ninetynine percent of fuelwood plantation in terms of hectare nearby mountains from villages and other along roads and the edge of streams. The ownership of the site planted by fuelwood species is mostly private owned which amounts to 90 percent. The owners of the plantation site have to render their tenure rights to VFA to establish fuelwood plantation by law if the County office designate the site for fuelwood planation. The fuelwood plantation is established and managed by VFA with voluntary labor of VFA members. The harvested products will be shared by VFA and the site owners with 9:1 ratio. 8. The servival rates of planted tree ranged from 75 percent to 95 percent and the reforestration of nearby forest is closely visible fuelwood raising status varied widely depending upon soil,light,location,and management of the plantation site. Application of fertilizer,particularly, seems to be very important to raise fuelwood in good condition. Among the 36 sample Villages 30 Villages have applied fertilizers after the establishment of the fuelwood plantations. After the plantation of fuelwood aftercares such as weedings, tendings,fertilizations are carried out for 2∼3years by the members of VFA, voluntarily, with no wages paid except fertilizers subsidied the Government. For autonomus fuelwood plantation protection a patrol team is organized by the VFA members. The inturn patrol team consisting of two VFA members makes intensive patrols during the season of fall through the spring of the following year which forest damages are heavily expected. These patrols have served for the prevention of collecting illegally forest products, control of destructive actions against forest facilities, prevention of forest fire, prevention of illegal hunting, etc. There were no villages hired full time patrolmen among the 36 sample villages. All chiefs of the VFA surveyed were serving without pay. It takes generally 4∼5years to harvest fuelwood after planting the seedlings. Weeding is taking place every year until the havest time comes, and the remains are not remains are not collected for fuel. They are spreaded and left around the tree for fertilizer. 9. Fuel production from the fuelwood plantation has been considerably low compared to what has been expected. The survey reveals that the average amount of fuel harvest out of the fuelwood plantation was 1,71 M/T per hectare. Expected or planned fuel production was fire M/T per hectare. The highest production turned out to be 10 M/T per hectare while the lowest 0.1 M/T. 10. The principal benefits of the fuelwood project would be: (a) production of forest fuel which would replace illegal cutting and gathering of timber and other forest products. (b) labor saving in collecting fuel. (c) creation of permanent timber producing forests as a secondary purpose of the fuelwood plantation projects, and consequent reduction of soil errosion and flood protection. (d) increase inseedling farmer's income and creation of employment opportunities for the labor intensive seedling farms. (e) beautification of mountains and villages, and institutional building at village level leading to self reliance. 11. Quantitative measurement of direct benefits a and b is attempted. There are no explicit markets for fuetwood rural area any more. However fuelwood, more specifically trimmed tree branches sometimes are bought and sold among the residents in a village. Price of the fuelwood is around 1,000 won per 60㎏,a loadful of “gike”(A-frame). It is assumed that full yield would be reached in eighth year and would equal 5 tons/ha. Yields would build up 0.5 ton in forth year, 1 tons in fifth year, 2 tons in sixth year, 4 tons in seventh year and there-after 5 tons/ha until 20th year. There will be no production until fourth year. During years 1 to 3, there would be a certain amount of grass and weeds produced but usually it is left on the site for fertilizer and value of this would be merely equal to the opporunity cost of labor maintaining the fuelwood plantation. 12. When there were no fuelwood plantations, a household had to spent average 41 days per annum to stock up 1 year fuel requirement during mostly winter time. With fuelwood plantation, a rural household spends about 7 days for a year to serve fuelwood plantation including forest product harvest. Value of time saving may be evaluated as an opportunity costs of labor. 75% of annual average wage rate for man and woman in 1977 was 1,500 Won/day. Labor saving value per ha of fuelwood plantation was estimated to be about 16 days when substracting the effect of 45% composition rate of briquette and agricultural residuals in fuel consumption. Savings of coal resources and agricultural residues did not occur in the survey as country to expected. 13. The cost per ha of plantation establishment is estimated to be around 112,216 Won. Materials, transport and overhead are evaluated at their financial costs. Supervision costs are valued at 4,233 Won/day which is skilled laborer’s wage rate in 1977. Village volunteer labor which comprises 57% of total cash valued establishment cost has been valued at 1,500 Won/day which is 75% of annual average farm wage rate in 1976. The volunteer labor cost is 63,214 Won/ha. 14. The maintenance costs of fuelwood plantation is composed of weeding brushing for the first 4 years and plantation patrol costs. This is valued at 3,047 Won. Production costs may be divided into labor cost for harvest and fertilizer costs. Labor cost is estimated at 2,417 Won per ha and fertilizer cost is 1,303 Won/ha. Therefore, the total production costs for fuel is 3,786 Won/ha. 15. For cost and benefit streams, the rate of return is estimated to be 18.8%. The benefit cost ratio was 2.29 and 1.81 when 12% and 15% discount rates were used respectively. When the fuel production was valued at opportunity cost of labor. 1,500 Won/day, IRR is estimated to be 19.78%. It was assumed that one man can harvest and carry (by A-frame)180㎏/day. The transport distance was assumed to be 1 km.
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A class of binary matrices preserving rank under matrix addition and its application
Kil-Chan Ha 한국전산응용수학회 2004 Journal of applied mathematics & informatics Vol.16 No.-
An open problem proposed by Safavi-Naini and Seberry inIEEE transactions on information theory(1991can be reduced to a com-binatorial problem on partitioning a subset of binary matrices. We solvethe generalized Naini-Seberry’s open problem by considering a certain classof binary matrices. Thus a subliminal channel of r > 1 bit capacity is sys-tematically established for Naini-Seberry’s authentication schemes. Wealso construct concrete examples.
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