• Title/Summary/Keyword: Burning area

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A Study on Characterization of Expansion Agent in Mortar with Light Burned Dolomite By-Product (경소백운석(輕燒白雲石) 부산물(副産物)을 활용(活用)한 바닥 몰탈용 팽창재(膨脹材)의 특성검토(特性檢討))

  • Lee, Keon-Ho;Min, Sung-Eoi;Lee, Hyoung-Woo;Cho, Jin-Sang;Cho, Kye-Hong;Han, Choon
    • Resources Recycling
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    • v.21 no.6
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    • pp.12-22
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    • 2012
  • This study investigated a utilization technology of light burned dolomite. light burned dolomite ($CaMg(CO_3)_2$) generated in furnace (steel manufacturer) is an alternative to quick lime. Using light burned dolomite has an effect on reducing the consumption of fluorite slag MgO concentration in supersaturated solution by prolonging the life of softening effect. Armophous MgO, not containing periclase is formed by firing dolomite under $800^{\circ}C$. It has larger surface area and higher reactivity than periclase, and also shows better expansion effect than quicklime. Due to those effects, therefore, armophous MgO produced from light burned dolomite is used as an alternative expansion agent in mortar. In the experiment, characteristics of light burned dolomite were compared to those of existing expansion agents such as anhydrite and quicklime. Then, each expansion and shrinkage rates were measured over a period of about 3 months in both of 1m Jis mold at labscale and apartment mortar flooring at field scale. In the result, it was observed that light burned dolomite in mortar flooring more compensates for the expansion and shrinkage rates than the existing expansion agents, showing low expansion rate of below 0.05% and also decreases the crack.

Experiment on the Correlation between Mass Flux of Heptane and Material Property of Wall in Compartment Fire (구획 화재 시 벽면 재료 특성과 헵탄의 질량유속 상관관계 실험)

  • Park, Jung Wook;Shin, Yeon Je;Kim, Jeong Yong;You, Woo Jun
    • Fire Science and Engineering
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    • v.33 no.1
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    • pp.39-44
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    • 2019
  • In this study, the relationships between the material properties of the wall and the fuel mass flux in compartment fire. The fire resistant board (fire-board) and steel plate compartments are constructed with a 0.3 m width, 0.5 m height and 3.0 m length. To obtain the mass loss rate considering the location of the fire origin in compartment, experiments of a heptane pool fire are performed with a combustion area of $0.01m^2$ and $0.0225m^2$. The results show that the initial mass flux of heptane, $0.0087kg/m^2{\cdot}s$, is increased to $0.166kg/m^2{\cdot}s$ for fire board and $0.019kg/m^2{\cdot}s$ for steel plate. It means that the fire-scenario should be considered with the thermal characteristics of the material properties and geometric shapes of the compartment to predict fire propagation accurately in a compartment space.

Studies on Characteristics of the Growth and Development in Dioscorea alata L. (마(Dioscorea alata L.)의 생육과 수량 특성에 관한 연구)

  • Park, J.I.;Kang, Y.K.;Lee, B.Y.;Yoon, B.S.;Park, C.H.;Chang, K.J.
    • Journal of Practical Agriculture & Fisheries Research
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    • v.4 no.1
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    • pp.55-64
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    • 2002
  • This study was carried out to determine agronomic and genetic characteristics of the production process in tropical yams(Dioscorea alata L.). To make clear the possibility of cultivation of tropical yams in the Suwon area, the growth of the aboveground parts and the enlargement of tuber of Dioscorea alata, were investigated. The aboveground parts of the plants whose sprouted mother tuber were planted in late April were grown slowly until the 70-days after planting and grown rapidly after. From about 50-days after plantation, total length of vines slowly decreased due to the burning of the branch vines of lower modes. With regard to the branching progressed to 4th for the solo yam and to 6th for purple yam. The secondary branches tended to grow better. When the formation of daughter tubers was observed at the 50-days after planting, their enlargement was very slow. The rapid growth of tubers began at the 40-days and continued to the 90-days. General components such as protein, fiber, and lipid were higher in D. opposita rather than in D. alata. Hardness of D. alata was 2696.2 while that of D. opposita was 4946.9. Lightness of D. alata was 73.99, being higher than that of D. opposita.

A Study on the Cultivation Processes and Settlement Developments on the Mangyoung River Valley (만경강유역의 개간과정과 취락형성발달에 관한 연구)

  • NamGoong, Bong
    • Journal of the Korean association of regional geographers
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    • v.3 no.2
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    • pp.37-87
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    • 1997
  • As a results of researches on the cultivation processes and settlement developments on the Mangyoung river valley as a whole could be have four 'Space-Time Continuity' through a [Origin-Destination] theory model. On a initial phases of cultivation, the cultivation process has been begun at mountain slopes and tributory plains in upper part of river-basin from Koryo Dynasty to early Chosun Dynasty. At first, indigenous peasants burned forests on the mountain slopes for making 'dryfield' for a cereal crops. Following population increase more stable food supply is necessary facets of life inducing a change production method into a 'wetfield' in tributory plains matching the population increase. First sedentary agriculture maybe initiated at this mountain slopes and tributory plains on upper part of river basin through a burning cultivation methods. Mountain slopes and tributory plains are become a Origin area in cultivation processes. It expanded from up to down through the valleys with 'a bits of land' fashion in a steady pace like a terraced fields expanded with bit by bit of land to downward. They expanded their land to the middle part of river basin in mid period of Chosun Dynasty with dike construction techniques on the river bank. Lower part of river cultivated with embankment building techniques in 1920s and then naturally expanded to the tidal marshes on the estuaries and river inlets of coastal areas. 'Pioneer fringes' are consolidated at there in modern times. Changes in landscapes are appeared it's own characters with each periods of time. Followings are results of study through the Mangyoung river valley as a whole. (1) Mountain slopes and tributory plains on the upper part of river are cultivated 'dryfields' by indigenous peasants with Burning cultivation methods at first and developed sedentary settlements at the edges of mountain slopes and on the river terrace near the fields. They formed a kind of 'periphery-located cluster type' of settlement. This type of settlement are become a prominant type in upper part of river basin. 'Dryfields' has been changed into a 'wetfields' at the narrow tributory plains by increasing population pressure in later time. These wetfields are supplied water by Weir and Ponds Irrigation System(제언수리방법). Streams on the tributory plains has been attracted wetfields besides of it and formed a [water+land] complex on it. 'Wetfields' are expanded from up to downward with a terraced land pattern(adder like pattern, 붕전) according to the gradient of valley. These periphery located settlements are formed a intimate ecological linkage with several sets of surroundings. Inner villages are expanded to Outer villages according to the expansion of arable lands into downward. (2) Mountain slopes and tributory plains expanded its territory to the alluvial deposited plains on the middle part of river valley with a urgent need of new land by population increase. This part of alluvial plains are cultivated mainly in mid period of Chosun Dynasty. Irrigation methods are changed into a Dike Construction Irrigation method(천방수리방법) for the control of floods. It has a trend to change the subjectives of cultivation from community-oriented one who constructed Bochang along tributories making rice paddies to local government authorities who could be gather large sums of capitals, techniques and labours for the big dike construction affairs. Settlements are advanced in the midst of plains avoiding friction of distances and formed a 'Centrallocated cluster type' of settlements. There occured a hierarchical structures of settlements in ranks and sizes according merits of water supply and transportation convenience at the broad plains. Big towns are developed at there. It strengthened a more prominant [water+land] complex along the canals. Ecological linkages between settlements and surroundings are shaded out into a tiny one in this area. (3) It is very necessary to get a modern technology of flood control at the rivers that have a large volume of water and broad width. The alluvial plains are remained in a wilderness phase until a technical level reached a large artificial levee construction ability that could protect the arable land from flood. Until that time on most of alluvial land at the lower part of river are remained a wilderness of overgrown with reeds in lacks of techniques to build a large-scale artificial levee along the riverbank. Cultivation processes are progressed in a large scale one by Japanese agricultural companies with [River Rennovation Project] of central government in 1920s. Large scale artificial levees are constructed along the riverbank. Subjectives of cultivation are changed from Korean peasants to Japanese agricultural companies and Korean peasants fell down as a tenant in a colonial situation of that time in Korea. They could not have any voices in planning of spatial structure and decreased their role in planning. Newly cultivated lands are reflected company's intensions, objectives and perspectives for achieving their goals for the sake of colonial power. Newly cultivated lands are planned into a regular Rectangular Block settings of rice paddies and implanted a large scale Bureaucratic-oriented Irrigation System on the cultivated plains. Every settlements are located in the midst of rice paddies with a Central located Cluster type of settlements. [water+land] complex along the canal system are more strengthened. Cultivated space has a characters of [I-IT] landscapes. (4) Artificial levees are connected into a coastal emnankment for a reclamation of broad tidal marshes on the estuaries and inlets of rivers in the colonial times. Subjectives of reclamation are enlarged into a big agricultural companies that could be acted a role as a big cultivator. After that time on most of reclamation project of tidal marshes are controlled by these agricultural companies formed by mostly Japanese capitalists. Reclaimed lands on the estuaries and river inlets are under hands of agricultural companies and all the spatial structures are formed by their intensions, objectives and perspectives. They constructed a Unit Farming Area for the sake of companies. Spatial structures are planned in a regular one with broad arable land for the rice production of rectangular blocks, regular canal systems and tank reservoir for the irrigation water supply into reclaimed lands. There developed a 'Central-located linear type' of settlements in midst of reclaimed land. These settlements are settled in a detail program upon this newly reclaimed land at once with a master plan and they have planned patterns in their distribution, building materials, location, and form. Ecological linkage between Newly settled settlemrnts and its surroundings are lost its colours and became a more artificial one by human-centred environment. [I-IT] landscapes are become more prominant. This region is a destination area of [Origin-Destination] theory model and formed a 'Pioneer Fringe'. It is a kind of pioneer front that could advance or retreat discontinously by physical conditions and socio-cultural conditions of that region.

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Application of MODIS Aerosol Data for Aerosol Type Classification (에어로졸 종류 구분을 위한 MODIS 에어로졸 자료의 적용)

  • Lee, Dong-Ha;Lee, Kwon-Ho;Kim, Young-Joon
    • Korean Journal of Remote Sensing
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    • v.22 no.6
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    • pp.495-505
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    • 2006
  • In order to classify aerosol type, Aerosol Optical Thickness (AOT) and Fine mode Fraction (FF), which is the optical thickness ratio of small particles$(<1{\mu}m)$ to total particles, data from MODIS (MODerate Imaging Spectraradiometer) aerosol products were analyzed over North-East Asia during one year period of 2005. A study area was in the ocean region of $20^{\circ}N\sim50^{\circ}N$ and $110^{\circ}E\simt50^{\circ}E$. Three main atmospheric aerosols such as dust, sea-salt, and pollution can be classified by using the relationship between AOT and FF. Dust aerosol has frequently observed over the study area with relatively high aerosol loading (AOT>0.3) of large particles (FF<0.65) and its contribution to total AOT in spring was up to 24.0%. Pollution aerosol, which is originated from anthropogenic sources as well as a natural process like biomass burning, has observed in the regime of high FF (>0.65) with wide AOT variation. Average pollution AOT was $0.31{\pm}0.05$ and its contribution to total AOT was 79.8% in summer. Characteristic of sea-salt aerosol was identified with low AOT (<0.3), almost below 0.1, and slightly higher FF than dust and lower FF than pollution. Seasonal analysis results show that maximum AOT $(0.33{\pm}0.11)$ with FF $(0.66{\pm}0.21)$ in spring and minimum AOT $(0.19{\pm}0.05)$, FF $(0.60{\pm}0.14)$ in fall were observed in the study area. Spatial characteristic was that AOT increasing trend is observed as closing to the eastern part of China due to transport of aerosols from China by the prevailing westerlies.

A Study on Epidemiologic Characteristics of Recurrent Abdominal Pain in Elementary School Children (반복성 복통증 환아의 역학적 특징에 관한 조사)

  • Oh, Sang-Hyun;Yang, Eun-Seok;Park, Sang-Kee;Park, Young-Bong;Park, Jong;Park, Sang-Hak;Moon, Kyung-Rye
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.2 no.1
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    • pp.21-29
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    • 1999
  • Purpose: The aims of this study are to examine clinical characteristics, patterns of medical care utilization, and factors which determine medical care utilization of elementary school children with recurrent abdominal pain (RAP), to find posssible factors influencing the onset and the course of the disorder. Method: We performed questionnaires in Kwangju on children from two primary schools from June,1 1998 to June 30 and carried out statistical analysis. Result: 1) Total number of questionnaires were 1417. 715 were male and 702 were female and the ratio of male to female was 1.02:1. Average age was 10.3 years. 2) 268 children had RAP (18.9%), boys 132 (18.4%), girls136 (19.2%). 3) The duration of the pain within 10 minutes was 68.5%. 178 children with RAP (66.3%) visited the doctor. The utilization pattern of medical facilities of the pupils with RAP; the most frequently utilized medical facility was pediatrics (35.2%) and the order ran as internal medicine (31.5%), and pharmacy (29.25). The utilization pattern of medical facilities for the older students; the utilization rate of pediatrics decreased, but internal medicine increased. The major factors affecting the selection of the medical facility were geographic accessibility, kindness of the personnel, good results and traffic convenience. 4) Symptoms which were accompanied with abdominal pain were headache (44.5%), chest pain (28.2%), dizziness (26.6%), vomiting (9%), and 119 children (44.5%) had no accompanied symptoms. 5) In 95 children (35.3%) abdominal pain, occured at postprandial time, in 55 children (20.5%) before meal and in 39 children (14.7%) at school. The highest incidence rate of RAP was observed on Monday (21.4%), and the lowest on Saturday (8.7%). 6) The most frequent involved part of the abdomen was periumbrical area (38%) and the order ran as epigastrium and suprapubic area. The most frequent characteristics of abdominal pain were burning pain (36.9%) and the order ran as dull, cramping and colicky pain. Conclusion: RAP is a frequent disease entitiy in children. Too many times children with RAP are treated by other departments instead of Pediatrics. A child has a peculiar growth and development which is different to those from an adult with advancing years. So, it is necessary to choose special medical care and an adequate medical facility.

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Trends and Prospects of N. Korea Military Provocations After the Sinking of ROKS Cheon-an (천안함 폭침 이후 북한의 군사도발 양상과 전망)

  • Kim, Sung-Man
    • Strategy21
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    • s.34
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    • pp.58-92
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    • 2014
  • Even after S. Korea took 5.24 Measure(24 May 2014), N. Korea has not stopped raising provocations such as the shelling of Yeonpyeong Island, electronic and cyber attacks. To make matters worse, the communist country lunched long-range missiles(twice) and conducted 3rd nuclear test, escalating tensions which could possibly lead to an all-out war. Korean Government failed to respond properly. However, escalation into an all-out war was deterred by the CFC immediately carrying out its peacetime duty(CODA). The US made a rapid dispatch of its augmentation forces(Aircraft carrier, nuclear-powered submarine, strategic bomber, F-22) to the Korean Peninsula. In recognition of the importance of the Combined Forces Command, since May 2013 the Park Geun-Hye Administration has been pushing ahead with re-postponement of Wartime Operational Control Transfer(which initially meant the disassembling of the CFC as of 1 December 2015) More recently, there has been a series of unusual indicators from the North. Judging from its inventory of 20 nuclear weapons, 1,000 ballistic missiles and biochemical weapons, it is safe to say that N. Korea has gained at least war deterrence against S. Korea. Normally a nation with nuclear weapons shrink its size of conventional forces, but the North is pursuing the opposite, rather increasing them. In addition, there was a change of war plan by N. Korea in 2010, changing 'Conquering the Korean Peninsula' to 'Negotiation after the seizure of the Greater Seoul Metropolitan Area(GSMA)' and establishing detailed plans for wartime projects. The change reflects the chain reaction in which requests from pro-north groups within the South will lead to the proclamation of war. Kim, Jeong-Un, leader of N. Korean regime, sent threatening messages using words such as 'exercising a nuclear preemptive strike right' and 'burning of Seoul'. Nam, Jae-June, Director of National Intelligence Service, stated that Kim, Jung-Un is throwing big talks, saying communization of the entire Korean Peninsula will come within the time frame of 3 years. Kim, Gwan-Jin, Defense Minister, shared an alarming message that there is a high possibility that the North will raise local provocations or a full-fledged war whenever while putting much emphasis on defense posture. As for the response concept of the Korean Government, it has been decided that 'ROK·US Combined Local Provocation Counter-Measure' will be adopted to act against local provocations from the North. Major provocation types include ▲ violation of the Northern Limit Line(NLL) with mobilization of military ships ▲ artillery provocations on Northwestern Islands ▲ low altitude airborne intrusion ▲ rear infiltration of SOF ▲ local conflicts within the Military Demarcation Line(MDL) ▲ attacking friendly ships by submarines. Counter-measures currently established by the US involves the support from USFK and USFJ. In order to keep the sworn promise, the US is reinforcing both USFK and USFJ. An all-out war situation will be met by 'CFC OPLAN5027' and 'Tailored Expansion Deterrence Forces' with the CFC playing a central role. The US augmentation forces stands at 690,000 troops, some 160 ships, 2,000 aircraft and this comprise 50% of US total forces, which is estimated to be ninefold of Korean forces. The CFC needs to be in center in handling both local provocations and an all-out war situation. However, the combat power of S. Korean conventional forces is approximately around 80% of that of N. Korea, which has been confirmed from comments made by Kim, Gwan-Jin, Defense Minister, during an interpellation session at the National Assembly. This means that S. Korean forces are not much growing. In particular, asymmetric capabilities of the North is posing a serious threat to the South including WMD, cyber warfare forces, SOF, forces targeting 5 Northwestern Islands, sub-surface and amphibious assault forces. The presence of such threats urgently requires immediate complementary efforts. For complementary efforts, the Korean Government should consider ① reinforcement of Korean forces; putting a stoppage to shrinking military, acquisition of adequate defense budget, building a missile defense and military leadership structure validity review, ② implementation of military tasks against the North; disciplinary measures on the sinking of ROKS Cheon-an/shelling of Yeonpyeong Islands, arrangement of inter-Korean military agreements, drawing lessons from studies on the correlation between aid for N. Korea, execution of inter-Korean Summit and provocations from the North, and ③ bolstering the ROK·US alliance; disregarding wartime operational control transfer plan(disassembling of CFC) and creation of a combined division.

Interpretation on Making Techniques of Some Ancient Ceramic Artifacts from Midwestern Korean Peninsula: Preliminary Study (한반도 중서부 출토 일부 고대 세라믹 유물의 제작기술 해석: 예비 연구)

  • Lee, Chan Hee;Jin, Hong Ju;Choi, Ji Soo;Na, Geon Ju
    • Journal of Conservation Science
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    • v.32 no.2
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    • pp.273-291
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    • 2016
  • Some ceramic artifacts representing time-wise from comb pattern pottery in the Neolithic Age to white porcelain in Joseon Dynasty were selected from 7 sites in the north and south area of Charyeong Mountain Range in order to making techniques interpretation and development process of ancient ceramics through physicochemical and mineralogical quantitative analysis. Studied pottery samples in the Prehistoric times showed trace of ring piling in soft-type, and pottery in the Three Kingdoms Period had both soft and hard-type but kettle-ware and storage-ware were made with ring piling, but table-ware was made by wheel spinning. Different from pottery after the Three Kingdom Period when refinement of source clay was high, pottery in the Neolithic Age and in the Bronze Age exhibited highly mineral content in sandy source clay, which showed a lot of larger temper than source clay. Groundmass of celadon and white porcelain almost did not reveal primary minerals but had high content of minerals by high temperature firing. Ceramic samples showed some different in major and minor elements according to sites irrespective of times. Geochemical behaviors are very similar indicating similar basic characteristics of source clay. However, loss-on-ignition showed 0.01 to 12.59wt.% range with a large deviation but it rapidly decreased moving from the Prehistoric times to the Three Kingdom Period. They have correlation with the weight loss due to firings, according to burning degree of source clay and detection of high temperature minerals, estimated firing temperatures are classified into 5 groups. Pottery in the Neolithic Age and in the Bronze Age belongs from 750 to $850^{\circ}C$ group; pottery in the Three Kingdom Period are variously found in 750 to $1,100^{\circ}C$ range of firing temperature; and it is believed celadon and white porcelain were baked in high temperature of 1,150 to $1,250^{\circ}C$. It seems difference between refinement of source clay and firing temperature based on production times resulted from change in raw material supply and firing method pursuant to development of production skill. However, there was difference in production methods even at the same period and it is thought that they were utilized according to use purpose and needs instead of evolved development simply to one direction.

Development of a Pre-treating Equipment and the Carcass Disposal System for Infected Poultry (감염가금 전처리 및 폐사가축 처리시스템 개발)

  • Hong, J.T.;Kim, H.J.;Yu, B.K.;Lee, S.H.;Hyun, C.S.;Ryu, I.S.;Oh, K.Y.;Kim, S.;Kwon, J.H.;Tack, D.S.
    • Journal of Animal Environmental Science
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    • v.17 no.2
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    • pp.81-92
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    • 2011
  • When we bury the infected poultry into the ground, we have many problems such as the difficulty of making sufficient area for burying, environmental contamination by the leachate, unpleasant ordor. Also, in case of burning the carcass of the infected poultry, there are some problems such as high cost, dust, unpleasant odor, etc. It could cause environmental contamination which many peoples and environmental organization complains about. In this study, we develop a treating system which treats the infected poultry carcass in a environmental method preventing the environment contamination. This system is composed of many processes. The euthanasia system uses rigid vinyl to trap and to do a euthanasia the infected poultry with lethal gas, carbon dioxide. And then, with the tractor attached grappler infected poultry carcass could be put into the carcass treating system. The euthanasia system uses rigid vinyl to trap the infected birds and to confine lethal gas, carbon dioxide. Infected poultry carcass are moved to carcass disposal system by collecting device which is attached at tractor. The carcass treatment system (capacity of disposal : 6.3 $m^3$) is installed on a truck and do one pass work, which is input, crush, stir, sterilize, and discharge treated carcass. 1,000 chickens was killed within 9.7min by $CO_2$ (300L/min) in the tent (10 $m^3$). The collecting device could carry 142 chickens at a time, and the movable carcass treatment system could sterilize 2 tons carcass per hour (at one time). This treatment systems was eco-friendly because it reduced the volume of carcass by 31.9% with no wastewater generation.

A Study on the Resettlement Policy for the Hwajeon-Farmers of Illegal Reclamation in Gangweon-do (강원도(江原道) 화전정리사업(火田整理事業)에 대(對)한 소고(小考))

  • Kim, Tong Soo
    • Journal of Korean Society of Forest Science
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    • v.22 no.1
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    • pp.7-17
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    • 1974
  • Eighty percent of Gangweon-Do area is mountain forests, and of all others this province has the largest number of "Hwajeon-farmers" (who illegally reclaim the mountain forests to do farming as long as the soil is fertile enough to yield profit, but when it fails, move to other places to repeat the same forest burning, causing tremendous forest damages). In 1965 a 7-year plan was mapped out to exterminate this gipsy-farmers only to be suspended in 1969 to give way to the stronger urge from the national security view-point to first displace those isolated farmers set in deep mountains. In the meantime an increased number of the Hwajeon-farmers burned the forests, working new havoc. To cope with the situation, the provincial government lounched another 4-year plan in 1973 and has been enforcing the resettlement policy with renewed enthusiasm. Whether the plan will succeed depends entirely on the authority involved can solve the problems listed below with regard to the Hwajeon-farmers who are to lose their only means of survival and move down to the low-lands: 1) Their living must be taken care of until they can have definite means of self-supporting. 2) They must be provided with the opportunity to work in connection with the government-sponsored labor programs. 3) Not only the public organizations but also the private firms must give them the priority to get work. 4) The rural revitalization movement must expand the self-help reconstruction projects to absorb their labor powers. 5) The Hwajeon-farmers themselves must have the spirit of self-help and self-supporting. 6) All the citizens in the province must receive and protect them with brethren love. 7) The function of the watch-posts against the Hwajeon-farmers must be strengthened again.

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