• Title/Summary/Keyword: primary hand value

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Creep Crack Growth Properties of Rotor Steel under Constant Load and $C_t$ Condition (일정하중 및 일정$C_t$에서 로터강의 크리프 균열전파특성)

  • Jeong, Soon-Uk;Lee, Hun-Sik;Kim, Young-Dae
    • Proceedings of the KSME Conference
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    • 2001.06a
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    • pp.501-506
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    • 2001
  • The creep crack growth properties in 3.5NiCrMoV steel were investigated at $550^{\circ}C$ by using CT specimen under constant $C_t$ condition that was held during crack growth of 1mm distance. $C_t$ lely on load line displacement rate and $C^*$ usually increase with crack length though load is reduced in order to maintain constant $C_t$ value as crack growth. Fully coalesced area(FCA) ahead of crack tip tend to increase as $C_t$ increase to the critical value, and after that value FCA decrease. For the tertiary creep stage of crack growth test, the most of displacement is due to the steady state creep, except only small part due to the primary creep and other effects. Therefore, tests were mainly interrupted in the tertiary stage to obtain high value of $C_t$. At constant load and $C_t$ region, crack growth slope was 0.900 and 0.844 each, on the other hand $C^*$ slope was 0.480.

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Creep Crack Propagation Properties of Rotor Steel under Constant Load and Constant Ct Condition (일정하중 및 일정Ct에서 로터강의 크리프 귤열전파 특성)

  • Jeong, Soon-Uk
    • Journal of the Korean Society for Precision Engineering
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    • v.18 no.5
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    • pp.105-111
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    • 2001
  • The creep crack growth properties in 3.3NiCrMoV steel were investigated at 55$0^{\circ}C$ by using CT specimen under constant load and constant Ct condition that was held during crack growth of Imm distance. Ct lelied on load line displacement rate, C*usually increased with crack length though load is reduced in order to maintain constant Ct value as crack growth and appeared scatter band. At constant load and Ct region, crack growth slope was 0.900 and 0.844 each, on the other hand C* slope was 0.480. Fully coalesced area(FCA) ahead of crack tip increased as Ct increase to the critical value, and after that value FCA decreased. For the tertiary creep stage of crack growth test, the most of displacement was due to the steady state creep, except only small part due to the primary creep and other effects. Therefore, tests were mainly interrupted in the tertiary stage to obtain high value of Ct.

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Concentrations of Air Pollutants Measured at Kosan during ACE-Asia Intensive Observation Period (ACE-Asia 집중관측기간에 제주고산에서 측정한 대기오염물질의 농도 분포특성)

  • ;;;;Jianzhen Yu;Keith Bower
    • Journal of Korean Society for Atmospheric Environment
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    • v.18 no.6
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    • pp.487-501
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    • 2002
  • The concentrations of gaseous (NO$_{x}$, SO$_2$, and $O_3$) and particulate (Elemental Carbon, EC and Organic Carbon, OC) pollutants were measured to evaluate the air quality of Kosan. Samples were taken at Kosan during ACE-Asia (Asian Pacific Regional Aerosol Characterization Experiment) IOP (Intensive Observation Period) (2001. 3. 21~2001. 5. 5). The mean concentrations of $O_3$(46.3$\pm$10.4 ppb) is higher than those at urban area such as Seoul and Busan in Korea. On the other hand, the mean concentrations of other gaseous species, NO$_{x}$(4.73$\pm$3.42 ppb) and SO$_2$(0.62$\pm$0.63 ppb) are lower than those at great cities. So we concluded that there are a few primary sources emitting atmospheric pollutants. The concentration of EC is higher and the concentration of OC is similar with or higher than those at other background sites. The recent EC concentration is higher than those measured before at Kosan. We concluded that there are more primary sources than other background sites and the amount of primary source have increased recently in Jeju. Backward trajectory and co..elation analysis were used to study where the air masses originated and distinguish the source of pollutants. While NO$_{x}$ and $O_3$ were mainly emitted and formed from Jeju inland area, concentrations of SO$_2$, OC and EC were affected by Asian Dust from China. Using the mean relative standard deviation of ozone, cleanness coefficient was obtained. The cleanness coefficient value, is 1.6 times larger than the value in 1992. Recently, the air quality of Kosan has been contaminated because of the Asian Dust events since spring and the rapid industrialization development.pment.

Effect of Fabric Design Condition on the Mechanical Properties and Handle of Nylon/Cotton Union Fabrics for Sport Jacket (스포츠쟈켓용 나일론/면 교직물의 설계조건에 따른 역학적 특성과 태)

  • Kwon, Oh-Kyung;Song, Min-Kyu
    • Fashion & Textile Research Journal
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    • v.5 no.3
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    • pp.267-272
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    • 2003
  • Tactel(Nylon66) union fabrics were woven with the specification of 70d/34f nylon as warp for sport wear jacket. Weft yarn has three types; 100% cotton yarn, nylon core-spun yarn and nylon-polyurethane covering yarn as weft. Fabric structers were plain, twill and satin weave structure with the air jet loom. The mechanical properties of 8 fabrics were measured with KES-F and primary Hand Values and Total Hand Values were calculated. The results of the study were as follows: 1) There was little difference among LTs of N/CM fabric groups. RT of the fabrics with CM100's was bigger than that of fabrics with CM80's, resulting that the fabrics with CM100's have better formability. In terms of weaving structure, twill fabrics have shape deformation. 2) In comparison of RTs with weft yarn type, RT of N-PU covering yarn was the highest, followed by Nylon core-spun yarn and cotton yarn. Thus, the fabric with N-PU covering yarn has better stability of shape deformation. 3) Stretch yarn could express an excellent silhouette formation and twill and satin structures were better structure to make curvature on human form. 4) 2HG/G value of nylon core-spun fabrics was larger than that of N/C fabrics, but the silhouette formation of N/C fabrics was excellent. 5) The RC of N/PU was the highest, followed by N/P, and N/CM. 6) Koski of N/PU fabrics was the highest, Numeri of N/PU and N/Co-I were relatively higher than the others. THVs of N/CM-IV and N/CO-II were lower than the others, resulting that, twill structure was better than plain structure for a sport wear uses.

The Effects of Water-Absorbent Softner Treatment on the End-Use Properties of Polyester Knitted Fabrics (흡습유연 처리에 의한 PET 소재의 성능 변화 분석)

  • Kwon, Young-Ah
    • Fashion & Textile Research Journal
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    • v.12 no.5
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    • pp.676-682
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    • 2010
  • Superior hydrophilic properties will allow varieties of polyester(PET) fiber materials, fabrics and industrial materials a broader scope of use. The purpose of this study was to investigate the effect of water-absorbent softener treatment on the end-use properties and the hand of polyester knitted fabrics. Two different fabrics were knitted for the summer ladies' outwear; PET jersey and PET mesh. Variables were softner treatment and stitch type(jersey and mesh). Mechanical properties of the fabric samples were measured by KES-FB system. From these, primary hand values(HV) were evaluated by the conversion equation (KW-403-KTU) and the total hand value(T.H.V.) was calculated according to the KN-304 Summer. Both water-absorbent softner treatment and stitch types affected mechanical properties and hand values of PET fabrics. Mesh were thicker than single jersey stitch. As they became thicker, tensile, shear, and compressional energy increased. It appeared that coefficient of friction of mesh stitch was larger than that of single jersey stitch. The coefficient of friction and the mean deviation of surface roughness were decreased by softener treatment. After softner treatment KOSHI and SHARI of the both PET jersey and PET mesh decreased. However, FUKURAMI values of PET jersey increased and that of PET mesh decreased. The T.H.V. of the treated PET jersey was lower than that of the untreated one, while the T.H.V. of the treated PET mesh was higher than that of the untreated one. Overall T.H.V. of the single jersey was better than that of the mesh before and after softner treatment.

Evaluation on Large-scale Biowaste Process: Spent Coffee Ground Along with Real Option Approach

  • Junho Cha;Sujin Eom;Subin Lee;Changwon Lee;Soonho Hwangbo
    • Clean Technology
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    • v.29 no.1
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    • pp.59-70
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    • 2023
  • This study aims to introduce a biowaste processing system that uses spent coffee grounds and implement a real options method to evaluate the proposed process. Energy systems based on eco-friendly fuels lack sufficient data, and thus along with conventional approaches, they lack the techno-economic assessment required for great input qualities. On the other hand, real options analysis can estimate the different costs of options, such as continuing or abandoning a project, by considering uncertainties, which can lead to better decision-making. This study investigated the feasibility of a biowaste processing method using spent coffee grounds to produce biofuel and considered three different valuation models, which were the net present value using discounted cash flow, the Black-Scholes and binomial models. The suggested biowaste processing system consumes 200 kg/h of spent coffee grounds. The system utilizes a tilted-slide pyrolysis reactor integrated with a heat exchanger to warm the air, a combustor to generate a primary heat source, and a series of condensers to harness the biofuel. The result of the net present value is South Korean Won (KRW) -225 million, the result of the binomial model is KRW 172 million, and the result of the Black-Scholes model is KRW 1,301 million. These results reveal that a spent coffee ground-related biowaste processing system is worthy of investment from a real options valuation perspective.

Analysis of Forestry Structure and Induced Output Based on Input - output Table - Influences of Forestry Production on Korean Economy - (산업관련표(産業關聯表)에 의(依)한 임업구조분석(林業構造分析)과 유발생산액(誘發生産額) -임업(林業)이 한국경제(韓國經濟)에 미치는 영향(影響)-)

  • Lee, Sung-Yoon
    • Journal of the Korean Wood Science and Technology
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    • v.2 no.4
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    • pp.4-14
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    • 1974
  • The total forest land area in Korea accounts for some 67 percent of the nation's land total. Its productivity, however, is very low. Consequently, forest production accounts for only about 2 percent of the gross national product and a minor proportion of no more than about 5 percent versus primary industry. In this case, however, only the direct income from forestry is taken into account, making no reference to the forestry output induced by other industrial sectors. The value added Or the induced forestry output in manufacturing the primary wood products into higher quality products, makes a larger contribution to the economy than direct contribution. So, this author has tried to analyze the structure of forestry and compute the repercussion effect and the induced output of primary forest products when utilized by other industries for their raw materials, Hsing the input-output table and attached tables for 1963 and 1966 issued by the Bank of Korea. 1. Analysis of forestry structure A. Changes in total output Durng the nine-year period, 1961-1969, the real gross national product in Korea increased 2.1 times, while that of primary industries went up about 1. 4 times. Forestry which was valued at 9,380 million won in 1961, was picked up about 2. 1 times to 20, 120 million won in 1969. The rate of the forestry income in the GNP, accordingly, was no more than 1.5 percent both in 1961 and 1962, whereas its rate in primary industries increased 3.5 to 5.4 percent. Such increase in forestry income is attributable to increased forest production and rise in timber prices. The rate of forestry income, nonetheless, was on the decrease on a gradual basis. B. Changes in input coefficient The input coefficient which indicates the inputs of the forest products into other sectors were up in general in 1966 over 1963. It is noted that the input coefficient indicating the amount of forest products supplied to such industries closely related with forestry as lumber and plywood, and wood products and furniture, showed a downward trend for the period 1963-1966. On the other hand, the forest input into other sectors was generally on the increase. Meanwhile, the input coefficient representing the yolume of the forest products supplied to the forestry sector itself showed an upward tendency, which meant more and more decrease in input from other sectors. Generally speaking, in direct proportion to the higher input coefficient in any industrial sector, the reinput coefficient which denotes the use of its products by the same sector becomes higher and higher. C. Changes in ratio of intermediate input The intermediate input ratio showing the dependency on raw materials went up to 15.43 percent m 1966 from 11. 37 percent in 1963. The dependency of forestry on raw materials was no more than 15.43 percent, accounting for a high 83.57 percent of value added. If the intermediate input ratio increases in any given sector, the input coefficient which represents the fe-use of its products by the same sector becomes large. D. Changes in the ratio of intermediate demand The ratio of the intermediate demand represents the characteristics of the intermediary production in each industry, the intermediate demand ratio in forestry which accunted for 69.7 percent in 1963 went up to 75.2 percent in 1966. In other words, forestry is a remarkable industry in that there is characteristics of the intermediary production. E. Changes in import coefficient The import coefficient which denotes the relation between the production activities and imports, recorded at 4.4 percent in 1963, decreased to 2.4 percent in 1966. The ratio of import to total output is not so high. F. Changes in market composition of imported goods One of the major imported goods in the forestry sector is lumber. The import value increased by 60 percent to 667 million won in 1966 from 407 million won in 1963. The sales of imported forest products to two major outlets-lumber and plywood, and wood products and furniture-increased to 343 million won and 31 million won in 1966 from 240million won and 30 million won in 1963 respectively. On the other hand, imported goods valued at 66 million won were sold to the paper products sector in 1963; however, no supply to this sector was recorded in 1963. Besides these major markets, primary industries such as the fishery, coal and agriculture sectors purchase materials from forestry. 2. Analysis of repercussion effect on production The repercussion effect of final demand in any given sector upon the expansion of the production of other sectors was analyzed, using the inverse matrix coefficient tables attached to the the I.O. Table. A. Changes in intra-sector transaction value of inverse matrix coefficient. The intra-sector transaction value of an inverse matrix coefficient represents the extent of an induced increase in the production of self-support products of the same sector, when it is generated directly and indirectly by one unit of final demand in any given sector. The intra-sector transaction value of the forestry sector rose from 1.04 in 1963 to 1, 11 in 1966. It may well be said, therefore, that forestry induces much more self-supporting products in the production of one unit of final demand for forest products. B. Changes in column total of inverse matrix coefficient It should be noted that the column total indicates the degree of effect of the output of the corresponding and related sectors generated by one unit of final demand in each sector. No changes in the column total of the forestry sector were recorded between the 1963 and 1966 figures, both being the same 1. 19. C. Changes in difference between column total and intra-sector transaction amount. The difference between the column total and intra-sector transaction amount by sector reveals the extent of effect of output of related industrial sector induced indirectly by one unit of final demand in corresponding sector. This change in forestry dropped remarkable to 0.08 in 1966 from 0.15 in 1963. Accordingly, the effect of inducement of indirect output of other forestry-related sectors has decreased; this is a really natural phenomenon, as compared with an increasing input coefficient generated by the re-use of forest products by the forestry sector. 3. Induced output of forestry A. Forest products, wood in particular, are supplied to other industries as their raw materials, increasng their value added. In this connection the primary dependency rate on forestry for 1963 and 1966 was compared, i. e., an increase or decrease in each sector, from 7.71 percent in 1963 to 11.91 percent in 1966 in agriculture, 10.32 to 6.11 in fishery, 16.24 to 19.90 in mining, 0.76 to 0.70 in the manufacturing sector and 2.79 to 4.77 percent in the construction sector. Generally speaking, on the average the dependency on forestry during the period 1963-1966 increased from 5.92 percent to 8.03 percent. Accordingly, it may easily be known that the primary forestry output induced by primary and secondary industries increased from 16, 109 million won in 1963 to 48, 842 million won in 1966. B. The forest products are supplied to other industries as their raw materials. The products are processed further into higher quality products. thus indirectly increasing the value of the forest products. The ratio of the increased value added or the secondary dependency on forestry for 1963 and 1966 showed an increase or decrease, from 5.98 percent to 7.87 percent in agriculture, 9.06 to 5.74 in fishery, 13.56 to 15.81 in mining, 0.68 to 0.61 in the manufacturing sector and 2.71 to 4.54 in the construction sector. The average ratio in this connection increased from 4.69 percent to 5.60 percent. In the meantime, the secondary forestry output induced by primary and secondary industries rose from 12,779 million Wall in 1963 to 34,084 million won in 1966. C. The dependency of tertiary industries on forestry showed very minor ratios of 0.46 percent and 0.04 percent in 1963 and 1966 respectively. The forestry output induced by tertiary industry also decreased from 685 million won to 123 million won during the same period. D. Generally speaking, the ratio of dependency on forestry increased from 17.68 percent in 1963 to 24.28 percent in 1966 in primary industries, from 4.69 percent to 5.70 percent in secondary industries, while, as mentioned above, the ratio in the case of tertiary industry decreased from 0.46 to 0.04 percent during the period 1963-66. The mining industry reveals the heaviest rate of dependency on forestry with 29.80 percent in 1963 and 35.71 percent in 1966. As it result, the direct forestry income, valued at 8,172 million won in 1963, shot up to 22,724 million won in 1966. Its composition ratio lo the national income rose from 1.9 percent in 1963 to 2.3 per cent in 1966. If the induced outcome is taken into account, the total forestry production which was estimated at 37,744 million won in 1963 picked up to 105,773 million won in 1966, about 4.5 times its direct income. It is further noted that the ratio of the gross forestry product to the gross national product. rose significantly from 8.8 percent in 1963 to 10.7 percent in 1966. E. In computing the above mentioned ratio not taken into consideration were such intangible, indirect effects as the drought and flood prevention, check of soil run-off, watershed and land conservation, improvement of the people's recreational and emotional living, and maintenance and increase in the national health and sanitation. F. In conclusion, I would like to emphasize that the forestry sector exercices an important effect upon the national economy and that the effect of induced forestry output is greater than its direct income.

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A Study on Physical and Mechanical Properties of Breathable Waterproof Fabrics Manufactured with PTFE Membrane-fabric Composite (PTFE막-직물 복합체로 제조된 투습방수직물의 물성 및 역학특성에 관한 연구)

  • Jeong, Won-Young;An, Seung-Kook
    • Journal of the Korean Society of Clothing and Textiles
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    • v.26 no.12
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    • pp.1685-1693
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    • 2002
  • 다양한 용도로 사용되고 있는 라미네 이 팅 직물은 주로 별도로 제조된 고분자 필름 또는 막을 접착제, 열, 압력 등을 이용하여 기포(基布)와 결합시키는 방법으로 제조되어 진다. 이축연신시킨 Poly(tetrafluoroethylene) (PTFE) sheet는 매우 우수한 높은 투과성을 지니는 다공성 물질이 며, 본 연구에서는 이 막을 나일론 직물에 라미네이팅시킨 투습방수직물을 시료로 사용하여 라미네이팅 후의 역학특성 변화를 분석 하였다. 라미네이팅에 따른 투습방수직물의 물성과 역학특성의 변화에 관하여 살펴본 결과 다음과 같은 결과를 얻었다. 3-layer 라미네이팅 직물(base fabric-PTFE membrane-knitted lining)의 인열강도는 2-layer라미네이팅 직물 (base fabric-PTFE membrane)에 비해 매우 높게 나타났으며, 가공 전 직물과 비교하여 코팅직물에서 나타난 것과 같은 인열강도의 감소는 나타나지 않았다. 직물-PTFE 막 복합체 의 경우, 라미네 이 팅 이 파단강도 및 파단신도 의 증가에 기여 한 것으로 나타났으며 특히 3-layer 라미네이팅 직물의 경우, 신장률이 20%를 넘어서면서 강도가 현저히 증가하였다. 의복을 착용하였을 때 가해질 수 있을 정도의 소변형(small deformation) 하에서의 역학특성 에 있어서는 라미네이팅에 의해 전단특성이 가장 유의한 변화를 나타내었다. 전단강성(G)과 전단 히스테리시스 (2HG,2HG5)모두 증가하였고, primary hand value 중에서는 stiffness 가장 현저한 증가를 나타내었다

Dyeing Properties of Acetate/Functional Polyester Composite Yarn in Different Yarn Twisting Processes (연사방법에 따른 아세테이트/기능성 폴리에스터 복합사의 염색성에 관한 연구)

  • Kim, So-Jin;Jeon, Dong-Won;Park, Young-Hwan
    • Journal of the Korean Society of Clothing and Textiles
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    • v.30 no.2 s.150
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    • pp.255-265
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    • 2006
  • The purpose of this study was to examine the dyeing properties of four kinds of composite yams that were twisted in different processes. The composite yarns consist of acetate and functional polyester in ratio of 70 : 30. The composite yams were dyed at 100$^{circ}C$ and 125$^{circ}C$ using three types of dyes, disperse dyes for acetate fiber, PET fiber and PET-acetate blended fiber, in the three primary colors. The exhaustion($\%$) and K/S value were observed for each case. Also the effects of four different twisting processes to dyeing properties and physical properties were examined. Regardless of twisting methods, the composite yarns that were dyed at 125$^{circ}C$ had higher exhaustion($\%$) than those were dyed at 100$^{circ}C$ with all three types of dyes; However, tendency of the K/S value after reduction cleaning process was measured at 100$^{circ}C$ and the value measured 125$^{circ}C$ had a great difference with disperse dyes for acetate and dyes for PET. The difference of the K/S values of composite yarns, when dyed at 100$^{circ}C$ and 125$^{circ}C$ with disperse dyes for PET-acetate blended fiber, was almost negligible. According to twisting methods K/S values were in the following order: AP1 > AP3 > AP4> AP2. This means that AP1, treated at 220$^{circ}C$, had the highest K/S value and K/S value becomes higher as the yam is higher twisted and becomes lower as lower twisted. On the other hand, the dry shrinkage and wet shrinkage showed low shrinkage rate when the twist was high and steam setting temperature was high.

The Empirical Study on User Factor of LBS(Location-Based Service) Application Service in Mobile (모바일 LBS(Location-Based Service)응용 서비스의 사용자요인에 대한 실증적 연구)

  • Yim, Ki-Heung;Park, Eun-A
    • Journal of Information Technology Services
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    • v.6 no.3
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    • pp.225-239
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    • 2007
  • Mobile service is highly becoming in the limelight on information society by offering infringement problem about individual privacy or information by political and scientific interest This study is focusing on primary LBS application Mobile service that emphasize position confirmation, especially, looking for friends. The aim at this study grasps user productivity factor of LBS application Mobile service, and analyses whether some have relations with value and action determination of LBS application Mobile service. According to result, Mobile service applying position service is supported with usefulness and system quality, adaptedness. On the other hand, Usability and social effect, privacy weren't embossed by leading person. Mobile service applying position service is changed with a person who have experience looking for friend. This study has systematically analysed about LBS application service by leading person