• Journal of the Korean Geographical Society
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• v.31 no.3
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• pp.613-629
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• 1996

River terraces of glacial and interglacial periods are most developed in the Ungcheon River, midwestern coastal region of south Korea. Among these terraces, interglacial river terraces correspond to the thalassostatic terraces of eastern coastal region of Korea. Thus the former shoreline altitudes of the coastal region around Ungcheon River can be estimated by using relative heights of these interglacial thalassostatic terraces of Ungcheon River The former shoreline altitudes estimated from interglacial thalassostatic terraces of Ungcheon River are 80m, 50${\sim}$60m, 40${\sim}$45m, 30m, 25m(?), 15${\sim}$20m, and 10m. These estimates are almost identical with those of Quaternary sea levels of eastern coastal region. Among the above estimates of Ungcheon River, the former shoreline altituded of 15~20m and 10m correspond to the ancient sea levels of $\pm$18m and $\pm$10m of eastern coastal region which were injudged as the last interglacial culmination period and late warmer period of the last interglacia(5e and 5a substages of oxygen isotope stage), respectively. Therefore there is a possibility that the rest of the above former shoreline altitudes of the coastal region aroune Jngcheon River also correspond to those of eastern coastal region. On the basis of the above possibility it can be proposed that the eastern and western coastal region of Korean Peninsula have undergone tectonic uplift of equall amount since the middle Quaternary Period.

• Radiation Oncology Journal
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• v.18 no.4
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• pp.293-299
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• 2000

Purpose :We conducted a prospective non-randomized clinical study to evaluate the efficacy and toxic of the preoperative concurrent chemoradiotherapy for locally advanced unresectable rectal cancer. Materials and Methods: Between January 1995 and June 1998, 37 conecutive patients with locally unresectable advanced rectal cancer were entered into the study. With 3- or 4- fields technique, a total of 45 Gy radiation was delivered on whole pelvis, followed by 5.4 Gy boost to the primary tumor in some cases. Chemotherapy was done at the first and fifth week of radiation with bolus i.v. 5-Fluorouracil (FU) 370$\~$450 mg/m$^{2}$, days 1$\~$5, plus Leucovorin 20 mg/m$^{2}$, days 1$\~$5. OF 37 patients, 6 patients did not receive all planned treatment course (refusal in 4, disease progression in 1, metastasis to lung in 1). Surgical resection was undergone 4$\~$6 weeks after preoperative concurrent chemoradiotherapy. Results :Complete resection rate with negative margins was 94$\%$ (29/31). Complete response was seen in 7 patients (23$\%$) clinically and 2 patients (6$\%$) pathologically. Down staging of tumor occured in 21 patients (68$\%$). Treatment related toxicity was minimal except grade III & IV leukopenia in 2 patients, respectively. Conclusion : Preoperative concurrent chemoradiotherapy in locally advanced rectal cancer was effective in inducing down staging and complete resection rate. Treatment related toxicity was minimal. Further follow up is on-going to determine long term survival following this treatment.

• Korean journal of applied entomology
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• v.14 no.3 s.24
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• pp.111-131
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• 1975

The study has been carried out to investigate the occurrence, damage, characteristics of the pathogen, environmental conditions affecting the disease outbreak, varietal resistance, forecasting, and chemical control of bacterial leaf blight of rice in Korea since 1964. Bacterial leaf blight of rice became a major disease in Korea since 1960. A correlation was found between the annual increase of epidemics and increase of cultivation area of susceptible varieties, Jinheung, Keumnampung etc. Areal damage within the country showed that the more was at southern province, Jeonnam, Gyeongnam and western coast, and at flooded rice paddy. Yield reduction directly related with the amount of infection on upper leaves at heading stage. Fifty per cent of reduction resulted when the lesion area was more than 60 per cent. Less than 20 per cent of lesion area, however, was not affected so much on yield loss One hundred and six isolates collected from all over the country were classified as 8 strains by using 4 different bacteriophages in 1973. It was, however, only two in 1965. There were some specificities on varietal distributions among the strains such as that the Jinheung attacked mainly by strain A, B, C and I, those attack Kimmaze were A, B, H and I. Most strains were found from Tongil except D and E, whereas Akibare was only variety that attacked by strain E. Low temperature, high humidity, heavy rainfall and insutficient daylight favored the disease epidemics. Especially, typhoon and flooding at heading stage were critical factors. The earlier transplanting the more disease was resulted, and more nitrogen fertilizer application accerelated the diseased development in general. The resistance to the disease varied by growing stage of the sane plants. All of recommended varieties in Korea were susceptible to the disease except Norm No. 6 and Sirogane which moderately resistant. The pathogen, Xanthomonas oryzae, was detectable from extract of healthy seedlings that were grown in the field with an heavy infection previous year. The more bacteriophage in irigation water resulted the more disease outbreak, and the existence of more than 50 bacteriophages in 1ml. of irrigation water were necessary to initiate the disease out break. The curves representing occurrence of bacteriophages and disease outbreak were similar with 15 days interval. The survey of bacteriophage occurrence can be utilized in forecasting of the disease two weeks ahead of disease outbreak. Three applications of chemicals, Phenazin and Sangkel, in weekly intervals at the early satage of out-break depressed the symptom development, and increased yield by 20per cent. Proper period for the chemical application was just before the number of bacteriophage reaches 50 in 1ml. of irrigation water.

• Journal of the Korean association of regional geographers
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• v.4 no.2
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• pp.15-30
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• 1998

Physical geography is the discipline which deals with the relationship between man and natural environment. Therefore, it should be studied as the organized unity. In this paper I recognize the drainage basin as a framework outlining physical geography, describe the difference of inhabitant's life style due to the difference of natural environment in the drainage basin, and consider the meaning of drainage basin as a unit of life(and unit of regional geography). Munkyung is divided into three regions(intermontane basin region, middle mountainous region, marginal hilly region of the great basin) owing to the topographic characteristics. Subdivision in these regions is related closely to drainage network distribution, specially in intermontane basin region. And small regions have developed with the confluence point of $3{\sim}4$ order streams as the central figure. Intermontane basin region is the valley floor of Sinbuk-Soya-Kauun-Nongam stream located in the limestone region which is exposed according to Munkyung fault at its northern part. Small streams are affected strongly by the influence of the NNE-SSE or WNW-ESE tectolineament. Thus Kaeripryungro(鷄立嶺路), Saejaegil(새재길), Ewharyungro(伊火嶺路) and so on are constructed through the tectolineament. In the valley floors of small streams which flow into the intermontane basin, there are large floodplains. Floodplain in Sinbuk, Joryung, and Yangsan stream is used to paddy field or orchard, and in Nongam stream is used to paddy field or vegetable field. Hills are distributed largely in the periphery of intermontane basin. Limestone hills in Kauun and Masung basin are not continuous to the present low and flat floodplain, and most of those are used to forest land and field. On the other side. granite hills in Koyori are continuous to be used to the present floodplain, and they are used to residential area and field. In the middle mountainous region are there hilly mountains constructed in the geology of Palaeozoic Pyeongan System in northern area and Chosun System's Limestone Series in southern area, and banded gneiss and schist among Sobaeksan Gneiss Complex. In Palaeozoic Pyeongan System region are there relatively rugged mountains and ingrown meanders developed along tectolineaments. Chosun System's Limestone Series region builds up a geomorphic surface, develops various karst landforms. Mountainous area is used to field. On the other hand, especially in case of Hogye, valley bottom is wide, long, and discontinuous to slope, is used to paddy field dominantly. And schist region in Youngnam Block of Pre-Cambrian is rugged mountainous. Marginal hilly region of the great basin is hilly zone located in the margin of erosional basin(Bonghwa-Youngju-Yechon-Hamchang-Sangju). This region is lower geomorphic surface which is consisted of hills of $50{\sim}100$m height. Hills are used to field or orchard, and dissected gentle depression is used to paddy field.

• The Journal of Korean Academy of Prosthodontics
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• v.57 no.4
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• pp.342-349
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• 2019

Purpose: The purpose of this study was to retrospectively investigate the survival and success rate of implant-supported fixed prosthesis according to the materials in the posterior area. Other purposes were to observe the complications and evaluate the factors affecting failure. Materials and methods: Patients who had been restored implant prosthesis in the posterior area by the same prosthodontist in the department of prosthodontics, dental hospital, Chonbuk National University, in the period from January 2011 to June 2018 were selected for the study. The patient's sex, age, material, location, type of prosthesis and complications were examined using medical records. The KaplanMeier method was used to analyze the survival and success rate. The Log-rank test was conducted to compare the differences between the groups. Cox proportional hazards model was used to assess the association between potential risk factors and success rate. Results: A total of 364 implants were observed in 245 patients, with an average follow-up of 17.1 months. A total of 5 implant prostheses failed and were removed, and the 3 and 5 year cumulative survival rate of all implant prostheses were 97.5 and 91.0, respectively. The 3 and 5 year cumulative success rate of all implant prostheses were 61.1% and 32.9%, respectively. Material, sex, age, location and type of prosthesis did not affect success rate (P>.05). Complications occurred in the order of proximal contact loss (53 cases), retention loss (17 cases), peri-implant mucositis (12 cases), infraocclusion (4 cases) and so on. Conclusion: Considering a high cumulative survival rate of implant-supported fixed prostheses, regardless of the materials, implant restored in posterior area can be considered as a reliable treatment to tooth replacement. However, regular inspections and, if necessary, repairs and adjustments are very important because of the frequent occurrence of complications.

• Economic and Environmental Geology
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• v.52 no.3
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• pp.251-258
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• 2019

During the detailed geological survey around the southern Yangsan Fault, we newly found a Quaternary fault outcrop, which cuts unconsolidated sediments. The fault named the Sinwoo site, located in the Sinwoo pasture, Miho-ri, Duseo-myeon, Ulsan metropolitan city, is the first discovered Quaternary fault near the western part of the south Yangsan Fault. In this study, we provide information on characteristics of fault geometry and unconsolidated sediment at Sinwoo site based on the analysis data of topography, drainage, and lineament around the study site. The fault site is situated at pediment slope, but fan-shaped middle terrace, as well as thick sediment exposed at low terrace, indicates that the unconsolidated sediments have been deposited in the alluvial fan environment. The drainage develops to the third-order drainage system, and the first and the second drainage system meet at right angles to each other and form a radial drainage pattern. In addition, the NE-SW direction lineaments can be identified on the basis of the curvature of the river and the step of the topographic relief, running over the Sinwoo site. The fault of $N30-35^{\circ}E/79-82^{\circ}SE$ shows ~ 5.8 m apparent vertical offset and dominantly reverse-slip sense based on slickenline, rotation of pebbles, and drag folding at footwall. However, some discontinuous sediments observed in the footwall are interpreted as fissure-filling materials due to the strike-slip movement. Now, we are under multidisciplinary investigations of additional field survey and age dating in order to determine the evolution of Sinwoo site fault during the Quaternary.

• Journal of Life Science
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• v.31 no.1
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• pp.10-16
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• 2021

The consumption of fresh-cut agricultural materials is increasing due to increased public interest in health and the increase of single-person households. Most fresh-cut agricultural materials can be eaten without heating, thus easily exposing the consumer to food-borne pathogens. As a result, food-borne diseases are increasing worldwide. In the analysis of food-borne pathogens, it is important to detect the strains, but this is time consuming and laborious. Alternative detection methods that have been introduced, include polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE), which is performed without prior culturing. Samples of fresh-cut agricultural materials, such as vegetables, were analyzed by the culture-based method. In 129 samples, non-pathogenic Escherichia coli (3.9%), Bacillus cereus (31.8%), Clostridium perfringens (5.4%), Yersinia enterocolitica (0.8%), and enterohemorrhagic E. coli (0.8%) were detected. Eight samples contaminated with bacteria were randomly selected, further analyzed by PCR-DGGE, and compared with the culture-based method. Two cases detected non-pathogenic E. coli by PCR-DGGE only, despite a lack of detection by the culture method. It was supposed there was possibility of sample loss during its 10-fold dilution for appropriate cultivation. In the detection of high-risk food-borne pathogens, it was found that the detection limit was lower in PCR-DGGE than in the culture-based method (10 CFU/g). This suggests that PCR-DGGE can be alternatively used to detect strains. On the other hand, low-risk food-borne pathogens seem to have higher detection limits in PCR-DGGE. Consequentially, this study contributes to the improvement of food-borne pathogen detection and the prevention of its related-diseases in fresh-cut agricultural materials.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.3
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• pp.49-82
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• 1965

For the stable and high yields of low-land rice in Korea, the characteristics of rice plant for the vegetative and physiological responses, plant type formation, and yield components have been studied in order to obtain the fundamental data for the improvement of cultural practices, especially for the ideal fertilizer application. Furthermore the environmental conditions in Korea including temperatures, light, precipitation, and soil conditions have been compared in the broad sense with those in Japan, and the application of nitrogen, phosphorus, potassium, silicate and other micro-nutrients were described in relation to the characteristics of environmental conditions for the improvement of fertilizer application. 1. The average yield of polished-rice per 10 are in Korea is about 204 kg and this values are much less than those in Japan and Taiwan where they produce 77% to 13% more than in Korea. The rate of yield increase a year in Korea is 4.2 kg, but in Japan and Taiwan the rates of yield increase a year are 81 % and 62%, respectively. It was also found that the coefficient of variation of yield is 7.7% in Korea, 6.7% in Japan and 2.5% in Taiwan. This means that the stability of producing rice in Korea is very low when compared with those in Japan and Taiwan. 2. It was learned from the results obtained from the 'annual yield estimation experiment' that there are big differences in the respect of plant type formations between rice crops grown in Japan and Korea. The important differences found were as follows: (1) The numbers of spikelets per 3.3 square meters are 891 in Korea and 1, 007 in Japan(13% more than in Korea). (2) The numbers of tillers per 3.3 square meters at the stage of maximum tillering are 1, 150 in Korea, but in Japan they showed 19% more than in Korea. (3) The ratio of effective tillers to total tillers is 77.5% in Korea and 74.7% in Japan, which seems to be higher in Korea than in Japan. But the ratio in Korea is very low when considered the numbers of total tillers in both countries. (4) The ratio of grain to straw is 85.4% in Korea and 96.3% in Japan. 3. The average temperatures during the growing season at the area of Suwon, Kwangjoo and Taegu are almost same as those in the district of Jookokoo(Fookoo yama) in Japan, i.e., the temperatures during the rice-growing season in Korea are similar to those in the southern-warm regions of Japan. 4. Considering the minimum temperatures at the stage of limiting transplanting, 13$^{\circ}C$, the time of transplanting might be 30 to 40 days earlier than presently practicing transplanting time, which comes around June 10. 5. The temperatures during the vegetative growth in Korea were higher than those temperatures that needed in the protein synthesis which ate the main metabolism during this stage. However, the temperatures at the time of reproductive growth was lower than the temperatures that needed in the sugar assimilation which is main metabolism in this stage. In this point of view, it might be considered that the proper time of growing rice plant in Korea would be rather earlier. 6. The temperatures and the day light conditions at the time of first tillering stage of rice plant, when planted as presenting transplanting practices, are very satisfactory, but the poor day light length, high temperatures and too wet conditions in the time of last-tillering stage(mid or last July) might cause the occurrence of disease such as blast. 7. The heading stage of rice plants at each region through nations when planted as presently practicing method comes when the day light length is short. 8. It was shown that the accumulated average air-temperature at the time of maturing stage was not enough and the heading time was too late, when considered the annual deviations of mean temperatures and low minimum temperatures. 9. The nitrogen content of each plant part at the each growing stage was very high at the stage of vegetative growth when compared with the nitrogen content at the stage of reproductive growth after heading. In this respect it was believed to be important to prevent the nutrient shortages at the reproductive stages, especially after the heading. 10. The area of unsatisfactory irrigation paddy fields and natural rain-fed paddy fields are getting reduced in Korea. The correlation between the rate of reducing unsatisfactory irrigation and natural rain-fed paddy fields and the rate of yield increase were computed. The correlation coefficients(r) between the area of unsatisfactory irrigation paddy fields and yield increase were +0.525, and between the natural rain-fed paddy fields and yield increase, +0.832 and between the unsatisfactory irrigation plus natural rain-fed paddy fields and yield increase, +0.84. And there were. highly significant positive correlations between natural rain-fed paddy fields and yield increases indicating that the less the area of natural rain-fed paddy fields, the greater the yields per unit area. 11. The results obtained from the fertilizer experiments (yield performance trials) conducted in both Korea and Japan showed that the yield of non-fertilized plots per 10 are was 231 kg in Korea and 360 kg in Japan. On the basis of this it might be concluded that the fertility of soil in Korea is lower than that in Japan. Furthermore it was. also found that the yields of non-nitrogen applied plots per 10 are were 236 kg in Korea and 383 kg in Japan. This also indicates that the yields of rice in Korea are largely depending on the nitrogen content in the soil. 12. The followings were obtained when the chemical natures of soils in both Korea and Japan were compared. (1) The content of organic matter, total nitrogen, exchangeable calcium, and magnesium in Korea were no more than the half those in Japan. (2) The content of N/2 chloride and soluble silicate in low-land soil were on the average lower in Korea. (3) The exchange capacity of bases in Korea was no more than half that in Japan. 13. It was also observed by comparing the soil nature of the soil with high yielding capacity with the soil with low yielding capacity that the exchange capacity of bases, exchangeable calcium and magnesium, potassium, phosphorus, manganese, silicate and iron were low in the soil with low yielding capacity. 14. The depth of furrow slice was always deeper in the soil with high yielding capacity, and the depth of furrow slice in Korea was also shallower than that in Japan. 15. Summarizing the various conditions mentioned previously and considering the effects of silicate and trace elements such as manganese and iron besides three elements on the physiological and plant type formation of rice crops, more realistic and more ideal fertilizing practices were proposed. proposed.

• Radiation Oncology Journal
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• v.18 no.1
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• pp.17-25
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• 2000

Purpose : To evaluate the side effects, pattern of failure, and survival rate according to the sequence of postoperative adjuvant radiotherapy and chemotherapy, patients with stages II and III rectal cancer who had undergone curative resection were randomized to 'early radiotherapy group (arm I)' or' late radiotherapy group (arm II)', then we intend to determine the most effective sequence of the radiotherapy and chemotherapy. Materials and Methods . From January 1996 to March 1999, 313 patients with curatively resected stages II and III rectal cancer have been randomized to' early' or' late' radiation therapy group and received combined chemotherapy (5-FU 375 mg/m$^{2}$/day, ieucovorin 20 mg/m$^{2}$, IV bolus daily Dl-5, 8 cycles) and radiation therapy (whole pelvis with 45 Gy/25 fractions/s weeks). Arm I received radiation therapy from day 1 with first cycle of chemotherapy and arm II received radiation therapy from day 57 with third cycle of chemotherapy after completion of first two cycles. Preliminary analysis was peformed with 228 patients registered up to Jun 1998. Two out of the 228 patients were excluded because of double primary cancer. Median follow-up period was 23 months. Results :Local recurrence occurred in 11 patients (9.7$\%$) for arm I and 9 patients (8$\%$) for arm 11. There was no significant difference between both groups ( p=0.64). However, distant metastasis was found in 22 patients (19.5$\%$) for arm I and 35 patients (31.0$\%$) for arm II and which showed statistically significant difference between the two groups ( p=0.046). And neither 3-year disease-free survival (70.2$\%$ vs 59.2$\%$, p=0.2) nor overall survival (89.4$\%$ vs 88.0$\%$, p=0.47) showed significant differences. The incidence of leukopenia during radiation therapy and chemotherapy was 78.3$\%$ and 79.9$\%$ respectively but leukopenia more than RTOG grade 3 was only 2.1$\%$ and 6.0$\%$ respectively. The incidence of diarrhea more than 10 times per day was significantly higher in the patients for arm I than for arm II (71.2$\%$ vs 41.6$\%$, p=0.02) but this complication was controlled with supportive cares. Conclusion : Regardless of the sequence of postoperative adjuvant radiation therapy and chemotherapy after curative resection for rectal cancer, local recurrence rate was low with combined chemoradlotherapy. But distant metastasis rate was lower in early radiation therapy group than in late radiation therapy group and the reason is unclear. Most patients completed these treatments without severe complication, so these were thought to be safe treatments but the treatment compliance should be improved.

• Korean Journal of Soil Science and Fertilizer
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• v.15 no.2
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• pp.128-140
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• 1982

The distribution and practical classification of sandy paddy soils, which have the most extensive acreage among low productive paddy soils in Korea and have distinctive improvement effects, were studied to propose a tentative new classification system of sandy textured paddy soils as a means of improving the "Paddy Soil Type Classification" scheme used. The results are summarized as follows; 1. The potential productivity of sandy textured paddy soils was about 86% of normal paddy and the coefficient of variation was relatively high indicating that the properties of soils included were not sufficiently homogeneous. 2. As the poorly drained and halomorphic (> 16 mmhos/cm of E.C. at $25^{\circ}C$) sandy soils are not included in the "Sandy Soil" type according to the criteria of "Soil Type Classification", the recommendation of "adding clay earth" become complicated, and the soil type have to change when the salts washed away or due to ground water table fluctuations. 3. Coarse textured soils were entirely included in the "Sandy Soils" in the tentative criteria of sandy soil classification proposed, and the sandy soils were subdivided into 4 subtypes that is "Oxidized leaching sandy paddy", Red-ox. intergrading sandy paddy", "Reduced accumulating sandy paddy" and "Reduced halomorphic sandy paddy". The system of sandy soil classification proposed were consisted of following categories; Type (Sandy paddy)-Sub-type (4)-Texture family (5)-Soil series (48). 4. The variation of productivities according to the proposed scheme was more homogenized than that of the present device. 5. The total extent of sandy paddy soils was 409, 902 ha (32.3% of total paddy) according to the present classification system, but the extent reached 492,983 ha (38.9%) by the proposed system. The provinces of Gyeong-gi (88.923ha), Jeon-bug (69.717 ha), Gyeong-bug (55.390 ha) have extensive acreage of sandy paddy soils, and the provinces that had high ratio of sandy paddy soils were Gang-weon (58.9%), Gyeong-gi (50.5%), Chung-bug (48.5%), Jeon-bug (41.0%) etc. The ratio was increased by the proposed scheme, e.g. 71.4% in the case of Gang-weon prov. 6. According to the suitability group of paddy soils, the sandy soils mostly belong to 3 class (69.1%) and 4 class (29.2%). Coarse loamy textural family (59.2%) and coarse silty (16.1 %) soils were dominantly distributed. 7. The "Red-ox. intergrading subtype" of sandy paddy pertinent to 49.6% (245,012 ha) while the "Oxidized leaching sub-type" reaches to 33.5% (64,890 ha) and the remained 16.9% (83,081ha) belong to "Reduced accumulating sub-type (14.0%) and "Reduced halomorphic sub-type (2.9%)" according to the proposed scheme.