• The Journal of the Korea Contents Association
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• v.21 no.7
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• pp.317-327
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• 2021

The purpose of this study is to identify the priority factors for sustainable management of social enterprises related to early childhood education. To achieve the purpose of this study, sustainable management factors were extracted by examining previous studies related to social enterprises, and the priorities of factors were derived using the AHP method after conducting surveys of those who are related to early childhood education and social enterprises. As a result of the study, the priorities of the four major factors for sustainable management of social enterprises were confirmed in the following order: strategic factors, organizational factors, management capability factors, and social environment factors. And the priorities of the 16 sub-factors were confirmed in the following order: program originality, excellence of program content, CEO's leadership, expertise in operation and education, securing information on early childhood education market, etc. This study is meaningful in that it discovered the basic success factors for the performance and sustainability of social enterprises related to early childhood education and suggested directions for establishing management strategies for social enterprises related to early childhood education.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.50 no.12
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• pp.829-838
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• 2022

This study conducts Hypervelocity Impact(HVI) simulations considering space objects with various shapes and different impact angles. A commercial nonlinear structural dynamics analysis code, LS-DYNA, is used for the present simulation study. The Smoothed Particle Hydrodynamic(SPH) method is applied to represent the impact phenomena with hypervelocity. Mie-Grüneisen Equation of State and Johnson-Cook material model are used to consider nonlinear structural behaviors of metallic materials. The space objects with various shapes are modeled as a sphere, cube, cylinder, and cone, respectively. The space structure is modeled as a thin plate(200 mm×200 mm×2 mm). HVI simulations are conducted when space objects with various shapes with 4.119 km/s collide with the space structures, and the impact phenomena such as a debris cloud are analyzed considering the space objects with various shapes having the same mass at the different impact angles of 0°, 30° and 45° between the space object and space structure. Although space objects have the same kinetic energy, different debris clouds are generated due to different shapes. In addition, it is investigated that the size of the debris cloud is decreased by impact angles.

• Information Systems Review
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• v.25 no.1
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• pp.213-231
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• 2023

With the rapid development of live streaming commerce, online host as an information source plays a critical role in affecting live streaming performance. However, the impact of different product types on the relationship between online hosts and live streaming has been less studied. Based on the elaboration likelihood model (ELM) and information source theory, this study aims to empirically investigate what factors influence the sales of live streaming commerce and how product type moderates the relationship between them. The analysis of 11,422 live streaming commerce data collected for four months from October 10, 2021 to February 10, 2022 shows that, among the factors related to source credibility and attractiveness, multi-channel networks (MCN) and the number of followers positively affect the sales volume of live streaming commerce, whereas the reputation score harms the sales. Moreover, the moderating effect of the product type (i.e., ratio of involvement products) on the relationships is confirmed. The findings enrich the literature on live streaming commerce performance. The limitations and future research directions are also discussed.

• Korean Journal of Soil Science and Fertilizer
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• v.35 no.2
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• pp.118-126
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• 2002

To evaluate the correlations of microbial populations with soil healthiness and crop production and establish the criteria for microbial population of soil types. We analyzed the microbial community structure of 13 soils which were different in physical and chemical properties and cultivation methods. According to the analysis of microbial population suing the dilution plate method, the large differences of the microbial population structures among soil types were shown: aerobic bacteria $2-27{\times}10^6$, fluorescent Pseudomonas $1-1,364{\times}10^5$, Gram negative bacteria $1-126{\times}10^4$, and mesophilic Bacillus $1-110{\times}10^5$. The density of Gram negative bacteria was highest on red pepper cultivating soils (sample no. 4 and 6) of Umsung and Gesan, Chungbuk, and the density of the fluorescent Pseudomonas was highest on greenhouse soil (sample no. 7) of Jinju, Kyungnam. The crop productivity of three soils was high as compared with those of other soils. It was supposed that the density of fluorescent Pseudomonas and mesophilic Bacillus were correlated with the incresed crop production. By MIDI analysis, 579 strains isolated from 13 soils composed of a variety of microbes including 102 isolates of Agrobacterium, 112 isolates of Bacillus, 32 isolates of Pseudomonas, 44 isolates of Kocuria, and 34 isolates of Pseudomonas. Among the 624 isolates of Gram negative bacteria, Pseudomonas including P. putida and p. fluorescens occupied the highest density (51%), and Stenotrophomonas maltophilia and Burkholderia cepacia also appeared at high density. From RAPD analysis, the fluorescent Pseudomonas strains isolated from 13 soil types showed a high level of strain diversities and were grouped into 2 - 14 patterns according to soil types. Many of unknown bacteria were recovered from the paddy soil, and needed to be further characterized on the molecular basis.

• Journal of Korean Society of Forest Science
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• v.85 no.2
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• pp.329-339
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• 1996

This study is to investigate the effect of mycorrhizal development, growth, nutrient absorption of P. thunbergii seedlings inoculated with Pisolithus tinctorius(Pt. KJ-1) in relation to toxic materials in soil. The concentrations on copper solution applied to the soils were 0, 40, 120, 260, 430ppm. The results are summarized as follows : 1. The germination of P. thunbergii with Pt. increased greater than without ectomycorrhizal fungi. Mycorrhizal development showed a significant decreasing trend at high concentration, and tolerant Cu test with Pt. in agar plate media showed a decreasing trend at a high level. 2. P. thunbergii seedlings inoculated with Pt. showed that the shoot length was significantly promoted at 40, 120ppm copper levels, and that of noninoculated seedlings had the lowest effect in 430ppm copper level. 3. The outer shape of ectomycorrhizal root tips after inoculating Pt. on P. thunbergii seedlings appeared as a monopodial type, a fern-like type, and a cluster-like type at 0ppm, 40ppm levels, but only monopodial type came out at 260ppm, 430ppm copper levels. 4. Root length, no. of juvenile leaves, total length of juvenile leaves, total dry weight, no. of needles and total length of needles of P. thunbergii with Pt. increased greater than those of noninoculated seedling. Growth response of P. thunbergii seedling inoculated with Pt. increased significantly at 40ppm, 120ppm Cu levels. 5. As a result of analysis of growth medium, pH, Na, CEC increased at higher Cu level, and total nitrogen, organic matters, available phosphorous, K, Ca and Mg decreased at 40ppm, 120ppm Cu levels. As a result of an analysis about a copper within soils, it appeared having high Cu-concentration at 0ppm level of an inoculated Pt. and high Cu-concentration in noninoculated Pt. than in inoculated Pt. at higher level. 6. As a result of an analysis of shoot, N, P, and K-concentration were higher in noninoculated seedlings than in inoculated seedlings, and Cu-concentration was higher in inoculated seedlings than in noninoculated seedlings. The analysis of root resulted in a high N-concentration at 40ppm, 120ppm levels, in a high P-concentration in inoculated seedlings and in a high Cu-concentration in noninoculated seedlings. Cu-concentration was significantly higher at root than at shoot.

• Journal of Intelligence and Information Systems
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• v.20 no.4
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• pp.89-105
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• 2014

After emergence of Internet, social media with highly interactive Web 2.0 applications has provided very user friendly means for consumers and companies to communicate with each other. Users have routinely published contents involving their opinions and interests in social media such as blogs, forums, chatting rooms, and discussion boards, and the contents are released real-time in the Internet. For that reason, many researchers and marketers regard social media contents as the source of information for business analytics to develop business insights, and many studies have reported results on mining business intelligence from Social media content. In particular, opinion mining and sentiment analysis, as a technique to extract, classify, understand, and assess the opinions implicit in text contents, are frequently applied into social media content analysis because it emphasizes determining sentiment polarity and extracting authors' opinions. A number of frameworks, methods, techniques and tools have been presented by these researchers. However, we have found some weaknesses from their methods which are often technically complicated and are not sufficiently user-friendly for helping business decisions and planning. In this study, we attempted to formulate a more comprehensive and practical approach to conduct opinion mining with visual deliverables. First, we described the entire cycle of practical opinion mining using Social media content from the initial data gathering stage to the final presentation session. Our proposed approach to opinion mining consists of four phases: collecting, qualifying, analyzing, and visualizing. In the first phase, analysts have to choose target social media. Each target media requires different ways for analysts to gain access. There are open-API, searching tools, DB2DB interface, purchasing contents, and so son. Second phase is pre-processing to generate useful materials for meaningful analysis. If we do not remove garbage data, results of social media analysis will not provide meaningful and useful business insights. To clean social media data, natural language processing techniques should be applied. The next step is the opinion mining phase where the cleansed social media content set is to be analyzed. The qualified data set includes not only user-generated contents but also content identification information such as creation date, author name, user id, content id, hit counts, review or reply, favorite, etc. Depending on the purpose of the analysis, researchers or data analysts can select a suitable mining tool. Topic extraction and buzz analysis are usually related to market trends analysis, while sentiment analysis is utilized to conduct reputation analysis. There are also various applications, such as stock prediction, product recommendation, sales forecasting, and so on. The last phase is visualization and presentation of analysis results. The major focus and purpose of this phase are to explain results of analysis and help users to comprehend its meaning. Therefore, to the extent possible, deliverables from this phase should be made simple, clear and easy to understand, rather than complex and flashy. To illustrate our approach, we conducted a case study on a leading Korean instant noodle company. We targeted the leading company, NS Food, with 66.5% of market share; the firm has kept No. 1 position in the Korean "Ramen" business for several decades. We collected a total of 11,869 pieces of contents including blogs, forum contents and news articles. After collecting social media content data, we generated instant noodle business specific language resources for data manipulation and analysis using natural language processing. In addition, we tried to classify contents in more detail categories such as marketing features, environment, reputation, etc. In those phase, we used free ware software programs such as TM, KoNLP, ggplot2 and plyr packages in R project. As the result, we presented several useful visualization outputs like domain specific lexicons, volume and sentiment graphs, topic word cloud, heat maps, valence tree map, and other visualized images to provide vivid, full-colored examples using open library software packages of the R project. Business actors can quickly detect areas by a swift glance that are weak, strong, positive, negative, quiet or loud. Heat map is able to explain movement of sentiment or volume in categories and time matrix which shows density of color on time periods. Valence tree map, one of the most comprehensive and holistic visualization models, should be very helpful for analysts and decision makers to quickly understand the "big picture" business situation with a hierarchical structure since tree-map can present buzz volume and sentiment with a visualized result in a certain period. This case study offers real-world business insights from market sensing which would demonstrate to practical-minded business users how they can use these types of results for timely decision making in response to on-going changes in the market. We believe our approach can provide practical and reliable guide to opinion mining with visualized results that are immediately useful, not just in food industry but in other industries as well.

• Journal of Global Scholars of Marketing Science
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• v.18 no.1
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• pp.1-31
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• 2008

Trust is central to human relationships, at all times and places. The importance of trust is fundamental in all areas of human life, not only in the area of business administration. 2,500 years ago in China, Confucius taught that the foundation of politics was the trust of the people, more important even than military strength or the supply of food. Shakespeare's play, "Much Ado about Nothing' is about trust and deception. These days, trust and transparency in a commercial organization's business culture form the basis of the 'social capital' by which that organization increases its productivity. A successful company raises productivity by the accumulation of social capital, derived from a trust relationship between business partners, and between the company and consumers. Trust is the crucial factor. At the national level, building trust determines a nation's competitiveness. For a company, long term trust relationships with customers are essential for its survival in a business environment of rapid change. Such relationships, based on trust, are important assets to ensure a company's competitive advantage, and need to be organic to that company's business culture. Because of this importance, trust relationships have been studied in diverse areas within business administration, and especially within marketing, where they form the basis of a successful relationship between producer and consumer. However, what has been lacking is a unified definition of trust. Research has been conducted on the basis of various definitions and models. The majority of researchers have not considered the multidimensional character of the concept of trust until now. Approaches based on a one dimensional model have undermined the value of research results. Furthermore, researchers have only considered trust and trustworthiness as a single component. The majority of research has explored the consequences of perceived trust for outcomes such as loyalty or cooperation, but has neglected the effects of trustworthiness upon the mechanisms of consumer trust. This study focuses on the dimension of trust from such a perspective. It seeks to verify the effect of trust on customer intentions by breaking it down into three separate components: 1) the salesperson, 2) the product/service, and 3) the company. The purposes of this paper are as follows: Firstly, we review the multidimensional nature of trust objects: the salesperson, the product/service, and the company. Secondly, we analyze the relationship between multidimensional trust and trustworthiness. Thirdly, we analyze the connection between trust and repeat purchase intentions for the maintenance of long term relationships. For these purposes the author has developed several hypotheses as follows: H1-1: The competence of a salesperson is positively associated with the trust given by the consumer to the salesperson. H1-2: The benevolence of a salesperson is positively associated with the trust given by the consumer to the salesperson. H2-1: The competence of product/service is positively associated with the trust given by the consumer to the product/service. H2-2: The benevolence of product/service is positively associated with the trust given by the consumer to the product/service. H3-1: The reputation of a company is positively associated with the trust given by the consumer to the company. H3-2: The physical environment of a company is positively associated with the trust given by the consumer to the company. H4-1: Trust in a salesperson is positively associated with repeat purchase intentions. H4-2: Trust in a product/service is positively associated with repeat purchase intentions. H4-3: Trust in a company is positively associated with repeat purchase intentions. The data was compiled from 366 questionnaires. 500 questionnaires were collected, but some of the data was considered unsuitable and inappropriate. The subjects of the survey were male and female customers purchasing products at department stores in Seoul, Daegu and Gyeongbuk. It was carried out between Oct. 25 and 29, 2007. The data was analyzed by frequency analysis using SPSS 12.0 and structural equation modeling using LISREL 8.7. The result of the overall model analysis is as follows: Chi-Square=445.497, d.f.=185, p-value=0.0, GFI=.901, RMSEA=.0617, NNFI=.986, NFI=.981, CFI=.989, AGFI=.864, RMR=.0872. The results of the overall model analysis were coherent. It was found that trust is a multi-dimensional construct, that each of the dimensions of trust are meaningful influences on customer's repurchase intention. Trust in a company may be the most relevant, while trust in a product/service and a salesperson may be less relevant to repurchase intentions. The effective factors in determining trust in a salesperson and a company's product/service were found to be competence and benevolence. Factors in determining trust in a company were its reputation and physical environment, and the relationship of each effective trust factor has been verified in this research. As a result, it was found that competence and benevolence have a meaningful influence on trust in a salesperson and in product/service. It was also found that a company's reputation influences the overall trust in the company significantly but a company's physical environment does not have much effect.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.368-370
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• 2013

투명 전극은 전기전도도를 갖는 동시에 가시광선을 투과하는 소재를 말하며, 구체적으로는 빛의 파장이 400~700 nm 영역대의 가시광선을 80% 이상 투과하며 전기전도도가 비저항으로 $10^{-3}{\Omega}cm$이하이거나 면저항이 $10^3{\Omega}$/${\Box}$소재를 의미한다. 투명 전극은 전기전도도에 따라 사용되는 용도가 다양하다. LCD, PDP, OLED 와 같은 평판디스플레이 및 3D 디스플레이의 투명전극으로 사용되는 핵심재료일 뿐만 아니라 터치스크린, 투명필름, 대전방지막, 열반사막, EMI 방지막, 태양전지 분야에 광범위하게 이용되고 있다. 일반적으로, 투명전극 박막에 가장 많이 사용되고 있는 소재는 ITO (indium tin oxide)이나, 주성분인 In의 사용량 증가로 상용 ITO 타겟 가격이 급등하고 있음으며, 고가의 ITO 타겟을 대체하기 위한 저가의 투명전극 소재 개발이 절대적으로 요구되며, 신규 소재 개발을 통한 기술력 우위 선점이 필수적으로 요구되는 상황이다. 본 연구에서는 기존에 디스플레이 분야에서 널리 활용되는 고가의 ITO를 대체하기 위한 다성분 금속산화물 투명전극 스퍼터링 타겟 제조기술을 개발하기 위한 연구로서, Metal이 첨가된 In-Ga-Zn-O기반의 3성분계 투명도전성 소재를 조성설계, 고밀도 균질 타겟 제조 및 투명전극 박막을 형성하는 연구를 실시하였다. 고체산화물 산화인듐(In2O3)분말, 산화갈륨(Ga2O3) 분말그리고 산화아연(ZnO)분말과 Metal을 몰비로 칭량한 후 분말을 폴리에틸렌제 포트에 넣고 에탄올을 충분히 채운 후 지르코니아(ZrO2) 볼(ball)을 이용하여 24 h 동안 볼 밀링(ball milling) 방법으로 혼합한 뒤, $120^{\circ}C$의 플레이트위에서 마그네틱 바로 stirring하면서 건조하였다. 이 분말을 건조기에서 완전히 건조한 후 알루미나 유발을 이용해서 pulverizing한 후 sieving기를 이용하여 분말의 조립화를 하였다. 이 분말을 금형에 넣고 300 kg/$cm^2$의 압력으로 press하여 성형한 뒤 대기중에서 소결하였다 소결을 위한 승온 온도는 $10^{\circ}C$/min이었고 소결은 $1,450^{\circ}C$에서 6 h 동안 하였다. IGZO target의 조성 비율은 1:1:12 (mol%)를 사용하였으며, 첨가한 Metal은 Boron (B), Germanium (Ge), Barium (Ba)을 사용하여 타겟을 제작하였다. M-IGZO 박막은RF magnetron Sputter를 이용하여 증착하였으며, 앞선 실험에서 제작한 타겟을 사용하여 M-IGZO박막을 투명전극으로 사용하기 위한 각각의 특성을 파악하였다. 모든 박막은 상온에서 증착을 하였으며, 증착된 박막두께를 측정하기 위해 ${\alpha}$-step IQ를 사용하였고, 광학적 특성을 분석하기 위해 UV-Visible spectrophotometer 로 투과율을 측정하였다. 그리고 전기적 특성을 측정하기 위해 Hall effect measurement 및 4-probe를 사용하였으며, 결정성 분석을 위하여 XRD를 이용하여 분석하였다. 표1은 M-IGZO타겟을 사용하여 증착시간에 따른 면저항 특성을 나타내었다. Ge, B, Ba이 첨가된 IGZO 박막은 증착시간이 증가할수록 면저항이 낮아짐을 알 수 있었다. 또한, Ge이 첨가된 IGZO 박막이 다른 금속이 첨가된 IGZO 박막의 면저항보다 현저히 낮음을 알 수 있었다. Fig. 1(a), (b), (c)는 각 타겟을 동일한 조건으로 증착을 하여 광학적특성을 나타내는 그래프이다. GZO 박막의 광학적 특성을 보면 가시광 영역에서 평균 투과율은 모두 80% 이상으로 우수한 광투과 특성을 보여 투명전자소자로 사용가능하다. 특히, 자외선 영역을 모두 차단하는 UV cut 능력이 우수함을 알 수 있었다. 따라서, 금속이 첨가된 IGZO 박막을 태양전지용 투명전극으로 사용할 경우, 자외선에 의하여 수명이 단축되는 현상을 줄여줄 수 있음을 기대할 수 있으며 내구성 향상에 크게 기여할 것으로 보인다. Fig. 2는 Ge=0, 0.5, 5%인 IGZO 투명전극을 총 40회 반복하여 증착을 실시한 후 각각의 면저항을 측정한 결과이다. 실험결과에 따르면 Ge가 0%, 5%인 IGZO 투명전극은 증착을 거듭할수록 면저항이 증가하는 결과를 나타내었으며, 0.5%인 IGZO 투명전극은 점차 안정화되어가는 결과를 나타내었다. 따라서 안정화 되었을 때 평균 면저항은 26ohm/sq.로 나타났으며, 광투과율은 Fig. 3과 같이 가시광영역에서 평균 80%이상의 결과를 보였으며, 550 nm에서는 86.36%의 우수한 특성을 나타내었다. 본 연구에서는 Metal이 첨가된 In-Ga-Zn-O기반의 3성분계 투명도전성 소재 target을 제작하여 RF magnetron sputter로 박막을 형성한 후 특성을 비교하였다. M-IGZO target 중 Ge (0.5%)을 첨가한 IGZO 타겟을 사용한 투명전극이 가장 우수한 특성을 보였으며, 제작된 M-target의 In 비율이 30% 정도로 기존의 ITO (90%) 대비하여 투명전극 제작 단가를 절감할 수 있다.

• Journal of Korean Society of Forest Science
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• v.101 no.3
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• pp.501-508
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• 2012

This study was carried out to compare species diversity of soil bacteria from Baekdudaegan mountain forests (Bonghwa-gun, Mungyeong-si and Sangju-si) in Gyeongsangbuk-do and to analyze the effects of soil environments on diversity and population of soil bacteria. Soil bacteria were isolated from soil samples by streak plate method, and identified by DNA extaction and 16S rDNA sequence analyses. The population of soil bacteria from the soil samples of Bonghwa-gun was the highest with $5.1{\times}10^5cfu/g$, and followed by those from Mungyeong-si and Sangju-si with $1.9{\times}10^5cfu/g$ and $1.1{\times}10^5cfu/g$, respectively. The population of soil bacteria from surface layer soil was the highest, and then gradually decreased according to soil depth. The increase in population of soil bacteria from soil samples of different sites was correlated with the increase of the altitude of soil sampling site, depth of A horizon, liquid phase among three phases of soil, water content and bulk density of soil. Two hundreds and sixty eight bacterial colonies from Bonghwa-gun were classified into 10 species, 8 genera. One hundred and thirty four bacterial colonies from Mungyeong-si were classified into 15 species, 9 genera. Forty four bacterial colonies from Sangju-si were classified into 5 species, 2 genera. The dominant species (occupancy rate) from Bonghwa-gun and Mungyeong-si were Bacillus weihenstephanensis (36% and 40%, respectively), and Sangju-si was Bacillus cereus (39%). The relationships between soil environment and community structure of soil bacteria were analyzed statistically by using ecological indices. The diversity, evenness and dominance indices of soil bacteria were 6.30, 2.04 and 0.59 in Bonghwa-gun, 9.09, 2.94 and 0.51 in Mungyeong-si, and 4.55, 2.34 and 0.71 in Sangju-si, respectively. The diversity and evenness indices were increased by the increase of water content, drainage condition and gravel content of soil, while the dominance index was decreased.

• Journal of the Korean GEO-environmental Society
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• v.20 no.2
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• pp.41-48
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• 2019

Soil compaction is one of the most important activities in the area of civil works, including road construction, airport construction, port construction and backfilling construction of structures. Soil compaction, particularly in road construction, can be categorized into subgrade compaction and roadbed compaction, and is significant work that when done poorly can serve as a factor causing poor construction due to a lack of compaction. Currently, there are many different types of compaction tests, and the plate bearing test and the unit weight of soil test based on the sand cone method are commonly used to measure the degree of compaction, but many other methods are under development as it is difficult to secure economic efficiency. For the purpose of this research, a portable penetration meter called the Free-Fall Penetration Test (FFPT) was developed and manufactured. In this study, a homogeneous sample was obtained from the construction site and soil was classified through a sieve analysis test in order to perform grain size analysis and a specific gravity test for an indoor test. The principle of FFPT is that the penetration needle installed at the tip of an object put into free fall using gravity is used to measure the depth of penetration into the road surface after subgrade or roadbed compaction has been completed; the degree of compaction is obtained through the unit weight of soil test according to the sand cone method and the relationship between the degree of compaction and the depth of the penetration needle is verified. The maximum allowable grain size of soil is 2.36 mm. For $A_1$ compaction, a trend line was developed using the result of the test performed from a drop height of 10 cm, and coefficient of determination of the trend line was $R^2=0.8677$, while for $D_2$ compaction, coefficient of determination of the trend line was $R^2=0.9815$ when testing at a drop height of 20 cm. Free fall test was carried out with the drop height adjusted from 10 cm to 50 cm at increments of 10 cm. This study intends to compare and analyze the correlation between the degree of compaction obtained from the unit weight of soil test based on the sand cone method and the depth of penetration of the penetration needle obtained from the FFPT meter. As such, it is expected that a portable penetration tester will make it easy to test the degree of compaction at many construction sites, and will lead to a reduction in time, equipment, and manpower which are the disadvantages of the current degree of compaction test, ultimately contributing to accurate and simple measurements of the degree of compaction as well as greater economic feasibility.