• Title/Summary/Keyword: low density

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A Comparision Study of LDPE Pyrolysis over Resin Additives and Inorganic Compounds of Silica Alumina Type (수지첨가제와 실리카알루미나 계열 무기물이 LDPE 수지의 열분해에 미치는 영향 비교 연구)

  • Bak, Young-Cheol;Choi, Joo-Hong;Kim, Nam-Kyung
    • Journal of Korean Society of Environmental Engineers
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    • v.28 no.6
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    • pp.596-602
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    • 2006
  • The effects of resin additives and inorganic compounds addition on the thermal decomposition of low density polyethylene(LDPE) resin have been studied in a thermal analyzer(TGA, DSC) and a small batch reactor. The silica-alumina type compounds tested were kaolinite, bentonite, perlite, diatomaceous earth, activated clay and clay. The resin additives were antiforgging-agent and longevity-agent. As the results of TGA experiments, addition of antifogging-agent, longevity-agent and clay increased the temperature of the maximum reaction rate($T_{max}$). The silica-alumina type inorganic materials increased the pyrolysis reraction rate in the order of activated clay, diatomaceous earth, bentonite, perlites, and kaolinite. In the DSC experiments, addition of antifogging-agent and clay decreased the heat of fusion and the heat of pyrolysis reaction. Bentonite decreased 20% of the heat of fusion and 25% of the heat of pyrolysis reaction. In the batch system experiments, the mixing of clay retarded the initial producing rate of fuel oil, but increased the yield of fuel oil. Addition of bentonite increased the yield of fuel oil from LDPE resin. Mixing of antifogging-agent and longevity-agent produced the fuel oil having lower carbon number. The amounts of the carbon number below 12 in fuel oil decreased with adding the clay. That below 23 in fuel oil increased with mixing of bentonite, perlite, kaolinite, and activated clay. But the mixing of diatomaceous earth did not affect the carbon contents of fuel oil from pure LDPE resin. In the silica-alumina type inorganic material used in this experiments, bentonite was the most effective from the pyrolysis heat, yields, and the characteristics of fuel oil.

The Biological Effects of β-Cyclodextrin on Antithrombotic Activity and Plasma Lipid Metabolism in Rats (흰쥐에서 혈액지질 대사 및 항혈전작용에 관한 베타사이클로덱스트린의 생물학적 효과)

  • Park, B. S.
    • Journal of Animal Science and Technology
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    • v.45 no.2
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    • pp.199-210
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    • 2003
  • The effect of feeding a cyclic oligosaccharide, $\beta$-cyclodextrin($\beta$CD) on plasma cholesterol and triacylglyceride concentrations and on antithrombotic activity were investigated in rats fed a control chow diet, or one either high in cholesterol or in saturated fat. The bleeding time of $\beta$CD-fed groups was significantly prolonged by 293%, 157% and 218% in normal, high cholesterol and high fat diet fed groups, respectively, as compared to the control group(p<0.05). The whole blood clotting time was significantly increased by 202%, 168% and 211% in normal, high cholesterol and high fat diet fed groups as compared to control group, respectively(p<0.05). The $\beta$CD diet caused a marked decrease in plasma total lipid(TL), triacylglyceride(TAG), total cholesterol (TC) and low density lipoprotein- cholesterol (LDL-C) concentrations. The plasma TL concentration was significantly decreased by 70%, 82% and 87% in normal, high cholesterol and high fat diet fed groups as compared to the control group, respectively(p<0.05). The plasma TAG concentration was significantly decreased by 89%, 43% and 59% in normal, high cholesterol and high fat diet fed groups, respectively, as compared to the control group(p<0.05). The plasma TC concentration was significantly decreased by 28%, 62% and 36% in normal, high cholesterol and high fat diet fed groups, respectively, as compared to the control group(p<0.05). The LDL-C concentration was significantly decreased by 39%, 54% and 25% in normal, high cholesterol and high fat diet fed groups as compared to control group, respectively(p<0.05). The plasma total bile acids contents of $\beta$CD group was significantly increased by 66%, 95% and 97% in normal, high cholesterol and high fat diet fed groups as compared to control group, respectively(p<0.05). The hepatic HMG-CoA reductase activity was significantly lowered by 41% in the $\beta$CD-fed group compared to normal diet fed rats(p<0.05). The fecal steroid excretions of the $\beta$CD groups was significantly increased by 167% in normal diet fed rats(p<0.05). These results suggest that the $\beta$CD has a biological active function on antithrombotic activity and is hypolipidemic, hypotriglyceridemic and hypocholesterolimic agents. These are all effects that can help to prevent obesity and coronary heart disease in humans.

A study on the reduction on magnetic susceptible artifacts through the usage of silicon (실리콘을 이용한 자화율 인공물의 감소에 관한 연구)

  • Choi, Kwan-Woo;Lee, Ho-Beom
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.12
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    • pp.5937-5942
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    • 2012
  • This study used silicon that is similar to the density of the tissue of the human body to compensate for the uneven areas that are in contact with air in order to reduce susceptible artifacts. The subjects of the study were 16 normal people and the areas of the human body in which there are a lot of uneven areas with complicated structure and a lot of susceptible artifacts were formed since the surface area that comes into contact with the air is large were the areas that were chosen to be examined. A 3.0T superconducting magnetic resonance device was used as the test equipment and SPIR images that are sensitive to magnetic differences were obtained as sagittal planes on a line that extended the metatarsal and the phalanges, including the middle of the longitudinal arc and the 5 distal phalanxes. The method of analysis was to reduce the susceptibility between the tissue and the air to discover the reduction of susceptible artifacts by comparing the SNR and CNR before and after applying silicon. A statistical analysis was utilized for the sample matching T examination. The results of the study revealed that the susceptible artifacts were reduced in the images of the uneven areas that were compensated and applied with silicon. The SNR increased in significant amount in correlation from $3.91{\pm}1.33$ before application to $21.69{\pm}4.52$ after application and the CNR decreased in significant amount in correlation from $28.97{\pm}8.20$ before application to $4.88{\pm}2.14$. In conclusion, this study did not affect the voxel but it was an innovative method of improvement that compensated for the fundamental issue of the difference in susceptibility between the air and the body. The application is simple and the study has great significance in that it proposed a method to reduce susceptible artifacts in a low cost and highly efficient manner.

Prevalence and Management of Dyslipidemia, Hypertension, Diabetes Among Adults in Gangwon-do, Korea: the 2013-2014 KNHSP (강원도 성인의 이상지질혈증, 고혈압, 당뇨병의 유병률과 관리: 국가건강검진(2013-2014) 자료의 분석결과와 시사점)

  • Jang, Sungok;Lee, Jongseok
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.1
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    • pp.625-636
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    • 2017
  • Dyslipidemia, hypertension, and diabetes are well-established risk factors for cardio-cerebrovascular disease (CVD). Although the prevalence of dyslipidemia among Korean adults is very high, its management is known to be poor. The aim of this study was to assess the prevalence, awareness, treatment, and control rates of dyslipidemia among adults aged 30 years and older in Gangwon-do, Korea. Analysis included 58,121 adults (29,123 males and 28,998 females) participating in the 2013-2014 Korea National Health Screening Program (KNHSP). Dyslipidemia was defined according to the treatment criteria rather than the diagnostic criteria in Korea. Therefore, high-low-density lipoprotein cholesterol (LDL)-cholesterolemia was deemed present in individuals with LDL-cholesterol levels that exceeded the appropriate risk-based threshold. The age-standardized prevalence was highest in dyslipidemia (32.5%), followed by hypertension (25.1%), and diabetes (9.4%). The awareness rate was 76.7% for hypertension and 74.7% for diabetes, but only 10.6% for dyslipidemia. The lowest patient treatment was found for dyslipidemia (9.4%). The control rate among those undergoing treatment was highest for hypertension (75.8), followed by dyslipidemia (63.3%), and diabetes (43.9%). The higher CVD-risk categories showed lower control rates of hyper-LDL-cholesterolemia. The prevalence of dyslipidemia was higher than hypertension and diabetes, but awareness and treatment rates were lower. Our findings indicate there is a wide gap between the prevalence of dyslipidemia and subsequent treatment, which suggests that effective strategies are required to improve dyslipidemia management. It would be worthwhile to strengthen the follow-up management of patients with dyslipidemia in the KNHSP, especially for the high risk group of CVD.

Seasonal and Spatial Distribution of Soft-bottom Polychaetesin Jinju Bay of the Southern Coast of Korea (진주만에서 저서 다모류의 시 · 공간 분포)

  • Kang Chang Keun;Baik Myung Sun;Kim Jeong Bae;Lee Pil Yong
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.35 no.1
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    • pp.35-45
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    • 2002
  • Seasonal quantitative van Veen grab sampling was conducted to characterize the composition and structure of the benthic polychaete community inhabiting the shellfish farming ground of a coastal bay system of Jiniu Bay (Korea). A total of 132 polychaete species were identified and the polychaetes accounted for about $80\%$ of overall abundance of benthic animals. There was little significant seasonal difference in densities (abundances) of polychaetes, Maximum biomass was obseued in summer (August) and minimum value was recorded in winter (February) and spring (May). Conversely, diversity and richness were lowest in summer, indicating a seasonal variability in the polychaetous community structure, The cluster analysis indicated that such a seasonal variability resulted mainly from the appearance of a few small, r-selected opportunists in spring and the tubiculous species of the family Maldanidae in summer. On the other hand, several indicator species for the organically enriched environments such as Capitelia capitata, Notoniashs Jatericeus and hmbrineris sp. showed high densities during all the study period. Density and biomass of univariate measures of community structure were significantly lower in the arkshell-farming ground of the southern area than in the non-farming sites of the bay, A similar general tendency was also found in the spatial distributions of species diversity and richness. Principal component analysis revealed the existence of different groups of benthic assemblages between the arkshell-farming ground and non-farming sites, The lack of colonization of r-selected opportunists and/or tubiculous species in the former ground seemed to contribute to the spatial differences in the composition and structure of the polychaetous communities. Although finer granulometric composition and high sulfide concentration in sediments of the arkshell-farming ground and low salinity in the northern area were likely to account for parts of the differences, other environmental variables observed were unlikely. The spatial distribution of polychaetes in Jiniu Bay may be rather closely related to the sedimentary disturbance by selection of shells for harvesting in spring.

The Construction Direction of the ROK NAVY for the Protection of Marine Sovereignty (국가의 해양주권 수호를 위한 한국해군의 전력건설 방향)

  • Shin, In-Kyun
    • Strategy21
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    • s.30
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    • pp.99-142
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    • 2012
  • Withe increased North Korea's security threats, the South Korean navy has been faced with deteriorating security environment. While North Korea has increased asymmetric forces in the maritime and underwater with the development of nuclear weapons, and China and Japan have made a large investment in the buildup of naval forces, the power of the Pacific fleet of the US, a key ally is expected to be weakened. The biggest threat comes from China's intervention in case of full-scale war with North Korea, but low-density conflict issues are also serious problems. North Korea has violated the Armistice Agreement 2,660 times since the end of Korean War, among which the number of marine provocations reaches 1,430 times, and the tension over the NLL issue has been intensifying. With tension mounting between Korea and Japan over the Dokdo issue and conflict escalating with China over Ieo do Islet, the US Navy has confronted situation where it cannot fully concentrate on the security of the Korean peninsula, which leads to need for strengthening of South Korea's naval forces. Let's look at naval forces of neighboring countries. North Korea is threatening South Korean navy with its increased asymmetric forces, including submarines. China has achieved the remarkable development of naval forces since the promotion of 3-step plan to strengthen naval power from 1989, and it now retains highly modernized naval forces. Japan makes an investment in the construction of stat of the art warship every year. Since Japan's warship boasts of its advanced performance, Japan's Maritime Self Defense Force is evaluated the second most powerful behind the US Navy on the assumption that submarine power is not included in the naval forces. In this situation, naval power construction of South Korean navy should be done in phases, focusing on the followings; First, military strength to repel the energy warship quickly without any damage in case of battle with North Korea needs to be secured. Second, it is necessary to develop abilities to discourage the use of nuclear weapons of North Korea and attack its nuclear facilities in case of emergency. Third, construction of military power to suppress armed provocations from China and Japan is required. Based on the above naval power construction methods, the direction of power construction is suggested as follows. The sea fleet needs to build up its war potential to defeat the naval forces of North Korea quickly and participate in anti-submarine operations in response to North Korea's provocations. The task fleet should be composed of 3 task flotilla and retain the power to support the sea fleet and suppress the occurrence of maritime disputes with neighboring countries. In addition, it is necessary to expand submarine power, a high value power asset in preparation for establishment of submarine headquarters in 2015, develop anti-submarine helicopter and load SLAM-ER missile onto P-3C patrol aircraft. In case of maine corps, division class military force should be able to conduct landing operations. It takes more than 10 years to construct a new warship. Accordingly, it is necessary to establish plans for naval power construction carefully in consideration of reality and future. For the naval forces to safeguard maritime sovereignty and contribute to national security, the acquisition of a huge budget and buildup of military power is required. In this regard, enhancement of naval power can be achieved only through national, political and military understanding and agreement. It is necessary to let the nation know that modern naval forces with improved weapon system can serve as comprehensive armed forces to secure the command of the sea, perform defense of territory and territorial sky and attack the enemy's strategic facilities and budget inputted in the naval forces is the essential source for early end of the war and minimization of damage to the people. If the naval power construction is not realized, we can be faced with a national disgrace of usurpation of national sovereignty of 100 years ago. Accordingly, the strengthening of naval forces must be realized.

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A STUDY ON 4 TYPE CONSTITUTION AND SIFE CHARACTER OF OBESE PATIENTS (비만인의 생활특성과 사상체질에 관한 연구)

  • KIM, DAL RAE
    • Journal of Sasang Constitutional Medicine
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    • v.9 no.1
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    • pp.303-313
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    • 1997
  • Disease depends on the three factors, agent, host and environment. According to history of disease, by early 1900s the case of deaths is infectious disease, in late 1900s care of infectious diseases and tremendous scale of chronic disease, i.e., heart disease, diabetes, cancers and etc, makes care of chronic diseases be a most important theme. Now, life-style of diet is being westernized and in high industry-oriented society, obesity makes attack fate remarkably increase and life-expectancy become short, so that it causes severe problem of health. Chronic disease, such as obesity, is not affected by specific agent, but depends of interaction between host and environmental factors. There is the theory of constitutional medicine in Korean Medicine. According to it, all the people have constitutional specificity and disease. Because obesity is a kind of disease, there is the corresponding constituent being apt to be fat. Oriental Medicine utilizes herb-medication, acupuncture, and massage-therapy in treating obesity. Therefore study on relationship between constituent and obesity for OPD patients of Sangji-Oriental Medicine Hospital is carried out. The results are summarized as followings. 1. 70.2% of obesity patients are Taeumin(太陰人), 26.9% of those are Soyangin(少陽人), 2.9% of thoese are Soeumin(少陰人). 2. Most cases, high value of Free Fat Acid and Triglyceride not that of Total Cholesterol and Low Density Lipoprptein is meaningful in obesity patient blood. The corelationship between lipid test and Constitution is meaningful in Triglyceride and Free Fatty Acid. 3. Obesity is not related with gene. 4. Obesity is not related with Boyak(Herb-Med : 補藥). 5. Obesity mostly happens after delivery, contraception and operation. 6. Obese Patients are apt to eat between meals, especially food of wheat flour such as a snack. 7. The aim of treating obesity is not persuit of beauty but of keeping healthy. 8. 2.2Kg of body weight is lost after 4 week-treatment. 9. Common cause of obesity is overeating of carbohydrate and lipid than meat.

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Altered Expression of ${\beta}_3$ Integrin on Sclerotic Aortic Valves in a Hypercholesterolemic Rabbit Model (고콜레스테롤혈증을 유발한 토끼의 대동맥 판막에서 ${\beta}_3$ Integrin 발현의 변화)

  • Park, Chan-Beom;Kim, Young-Du;Choe, Mi-Sun;Jin, Ung;Moon, Seok-Whan;Kim, Yong-Han;Kim, Chi-Kyung;Jo, Keon-Hyon;Kweon, Jong-Bum
    • Journal of Chest Surgery
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    • v.41 no.6
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    • pp.687-694
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    • 2008
  • Background: Although aortic valve sclerosis causes no significant hemodynamic alterations, it is associated with an increased risk of cardiovascular death and myocardial infarction. However, the role of ${\beta}_3$ integrin in aortic valve sclerosis remains unclear. Material and Method: Twenty male New Zealand rabbits were divided into two groups. Group 1 rabbits (n=10) received a normal chow diet, while group 2 (n=10) rabbits received a diet containing 1% cholesterol for 12 weeks. After the rabbits were euthanized, their aortic valves and ascending aortas were excised for analysis. Result: Total serum cholesterol ($2,148.3{\pm}1,012.5\;mg/dL$ versus $53.7{\pm}31.8\;mg/dL$, p<0.05), triglyceride ($240.4{\pm}218.3\;mg/dL$ versus $31.6{\pm}6.4\;mg/dL$, p<0.05), and low density lipoprotein (LDL)-cholesterol($2,065.3{\pm}960.9\;mg/dL$ versus $29.1{\pm}30.9\;mg/dL$, p<0.05) levels were significantly higher in the cholesterol diet group compared with the normal diet group. Myofibroblasts and macrophages were more highly expressed in the aortic valve leaflets of rabbits in the cholesterol diet group than of those in the normal diet group. A real-time polymerase chain reaction revealed decreased ${\beta}_3$ integrin mRNA levels in the hypercholesterolemic aortic valves and aortas. Conclusion: The present study shows that hypercholesterolemia induces aortic valve sclerosis. These findings suggest that alterations in ${\beta}_3$ integrin may playa role in the development of aortic valve sclerosis.

Changes of soil characteristics, rice growth and lodging traits by different fertilization and drainage system in paddy soil (논 토양에서 배수 및 시비조건에 따른 토양특성, 생육 및 도복 관련 형질의 변화)

  • Jeon, Weon-Tai;Park, Chang-Young;Park, Ki-Do;Cho, Young-Son;Lee, Jeom-Sig;Lee, Dong-Chang
    • Korean Journal of Soil Science and Fertilizer
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    • v.35 no.3
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    • pp.153-161
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    • 2002
  • The installation of subsurface drainage equipment is required for generalized use of paddy field and to improve soil productivity. The internal drainage of paddy field has improved root condition from the increasing of oxygen supply and removing noxious elements. This experiment was carried out to determine the effects of fertilization and drainage system on soil characteristic, growth and lodging trait of rice in paddy soil. A subsurface drainage system was installed a depth of 0.8m. Three fertilizer treatments were applied : 1) Conventional fertilized plot, 2) Controlled-release fertilized plot, 3) No-fertilized plot. In conventional plot, 110 kg N (as urea 46%), 45 kg P (as fused phosphate 20%) and 57 kg K (as potassium chloride 60%) per hectare fertilizers were applied. Controlled-release fertilizer was applied by 70% of N compared to the conventional plot. During the rice cropping, the water depth decrease was two times higher in subsurface drainage(SD) plot than non-drained(ND) plot. After harvesting of rice, the bulk density of sub-soil(10-20cm depth) was lower in SD plot than ND plot. After the experiment, the surface soil pH was high at SD plot but sub-soil was high at ND plot. Organic matter content was higher in all soil layer for SD plot than fro ND plot. Available $P_2O_5$ was not different between SD and ND plot for surface soil, but was high for SD plot for sub soil. The $NH_4{^+}-N$ content of soil, shoot dry matter, total nitrogen and $K_2O$ of rice plant were greater after panicle formation stage in SD plot. Total nitrogen content, $P_2O_5$ and $K_2O$ of rice root were high in SD plot after heading. Though the gravity center and 3rd internode length were greater, pulling force of rice root was higher in SD plot than ND plot. Rice yield in SD plot were low at conventional and controlled-release fertilized plot because of the greater field lodging, but yield in SD plot was high at no-fertilized plot. This study indicates that the fertilization level should be decrease on subsurface drainage system for rice cropping.

Incorporation Effect of Green Manure Crops on Improvement of Soil Environment on Saemangeum Reclaimed Land during Sorghum×Sudangrass Hybrid Cultivation (수수×수단그라스 재배시 녹비작물 혼입에 따른 새만금간척지 토양환경 개선 효과)

  • Yang, Chang-Hyu;Lee, Jang-Hee;Baek, Nan-Hyun;Jeong, Jae-Hyeok;Cho, Kwang-Min;Lee, Sang-Bok;Lee, Gyeong-Bo
    • Korean Journal of Soil Science and Fertilizer
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    • v.45 no.5
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    • pp.744-748
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    • 2012
  • This study was carried out to investigate the incorporation effect of green manure crops (GMC) such as the hairy vetch on improvement of soil environment in reclaimed land during sorghum${\times}$sudangrass hybrid (SSH) cultivation over the past three years from 2009 to 2011. Plots consisted of conventional fertilization (CF) and incorporation of GMC were divided by rates of additional nitrogen fertilizer ($100kg\;ha^{-1}$) and decreased percentage of 30 50 70 100 fertilization in addition to non nitrogen fertilization (NNF). Soil physico-chemical properties, growth and yield potential were examined. The results were as follows. The testing soil was showed strong alkaline saline soil with low organic matter contents and less available phosphate while exchangeable sodium and magnesium were higher. Soil salinity was increased during cultivation of summer crop. However, SSH was not affected by salt content. The fresh weight of GMC at incorporation time was $18,345kg\;ha^{-1}$. Content of total nitrogen at incorporation time was 3.09% and the C/N ratio was 12.8. Fresh and dry matter yield of SSH were higher in the order of 30%, CF, N50%, N70%d, N100%, and NNF. Fresh and dry matter yield of SSH increased in the order of CF ($55,050kg\;ha^{-1}$, $16,250kg\;ha^{-1}$), N contents from 30% to 9%. Soil physical properties, such as bulk density were decrease with incoporation of GMC, while porosity was increased. Soil chemical properties, such as pH was decreased while content of exchangeable calcium, available phosphate, and organic matter were increased. Also contents of exchangeable sodium and potassium were decreased with incorporation of GMC than those before experiment. Thus, we assumed that incorporation of hairy vetch was more effective that can lead to reduce chemical nitrogen fertilizer and to improve soil environment in cultivating SSH on Saemangeum reclaimed land.