• Title/Summary/Keyword: logs

검색결과 723건 처리시간 0.019초

국내 대구경 시추공 굴진 중 Extended Leak-Off Test 수행 사례 보고 (Report on Extended Leak-Off Test Conducted During Drilling Large Diameter Borehole)

  • 조영욱;송윤호;박세혁;김명선;박인화;이창현
    • 터널과지하공간
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    • 제32권5호
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    • pp.285-297
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    • 2022
  • 본 고에서는 한반도 동남권에 분포하는 주요 단층대에 대한 장기 거동 및 미소진동 관찰을 목적으로 하는 시추공 기반 심부 복합지구물리 모니터링 시스템 구축의 일환으로 수행된 대구경 시추공 굴착 현장에서 이루어진 Extended Leak-Off Test (XLOT)에 대한 내용 및 결과를 보고한다. 다양한 시추공 센서 설치를 위한 모니터링공의 굴착은 ~1 km 깊이에서 최종 구경 200 mm 이상을 확보하는 것을 목표로 하여, 중간 깊이까지 12" 구경의 시추공 굴진 및 케이싱 설치, 이후 최종 심도까지 7-7/8" 구경의 시추공을 굴진하는 것으로 설계되었다. 현장 여건에 맞추어 약 504 m 깊이까지 12" 구경의 시추공이 굴착되었으며, API 규격의 8-5/8" 케이싱을 설치하고 배면과 암반 간의 틈새(annulus)에 대한 세멘팅 작업을 수행하였다. 이후 하부 구간 굴진(7-7/8")에 앞서 세멘팅 건정성 확인 및 암반 응력 측정 등을 목적으로 XLOT를 수행하였다. 약 4 m 길이의 나공 구간(open hole)을 확보하고, 상부에 설치된 케이싱을 이용해 물을 주입하여 시험 심도의 암반을 가압하였다. XLOT 수행 과정에서 주입 유량에 따른 시험 구간 내 압력 변화 양상을 실시간 모니터링 하였으며, 이 자료들을 일부 활용하여 현장 시추공 조건에서의 암반 투수율을 해석하였다.

일본잎갈나무와 리기다소나무의 중량추정식 및 중량표 개발 (Development of Weight Estimation Equations and Weight Tables for Larix kaempferi and Pinus rigida Stand)

  • 강진택;고치웅;박정묵;임종수;이선정;원명수
    • 한국산림과학회지
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    • 제112권4호
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    • pp.472-489
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    • 2023
  • 본 연구는 우리나라 주요 침엽수종인 일본잎갈나무와 리기다소나무의 생중량과 건중량 도출을 위한 최적 추정식 도출과 최적 중량식에 의한 중량표를 개발하기 위해 수행되었다. 중량표를 개발하기 위하여 전국에 분포하고 있는 일본잎갈나무 150본, 리기다소나무 90본, 전체 240본을 샘플링하여 현장에서 생중량을 측정하고, 각 부위별 시료를 채취하여 실험실에서 건중량을 측정하였다. 원목의 생중량과 건중량을 추정하기 위하여 이용한 식은 흉고직경의 1변수식, 그리고 흉고직경과 수고를 이용하는 2변수식으로 구분하였다. 또한 생중량 및 건중량 추정식들에 대해 적합성 검증을 위하여 적합도지수(FI), 평균제곱근오차(RMSE), 추정표준오차(SEE), 잔차도 등의 통계량을 이용하였으며, 도출된 최적식에 의해 중량을 계산하여 적용성을 검토하였다. 이 결과 흉고직경만을 이용할 때 W = bD+cD2 그리고 흉고직경과 수고를 이용할 때 W = aDbHc가 선정되었다. 선택된 1변수 중량추정식 W = bD+cD2의 적합도지수는 0.91였으며, 2변수 중량추정식 식 W = aDbHc의 적합도지수는 0.95로 모두 높게 나타났다. 이들 추정식으로 일본잎갈나무와 리기다소나무에 대한 생중량 및 건중량표를 새롭게 작성하였으며, 20년전의 중량표와 비교할 때 두 수종 모두 생중량 및 건중량이 기존 중량표가 큰 것으로 나타났다.

U-마켓에서의 사용자 정보보호를 위한 매장 추천방법 (A Store Recommendation Procedure in Ubiquitous Market for User Privacy)

  • 김재경;채경희;구자철
    • Asia pacific journal of information systems
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    • 제18권3호
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    • pp.123-145
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    • 2008
  • Recently, as the information communication technology develops, the discussion regarding the ubiquitous environment is occurring in diverse perspectives. Ubiquitous environment is an environment that could transfer data through networks regardless of the physical space, virtual space, time or location. In order to realize the ubiquitous environment, the Pervasive Sensing technology that enables the recognition of users' data without the border between physical and virtual space is required. In addition, the latest and diversified technologies such as Context-Awareness technology are necessary to construct the context around the user by sharing the data accessed through the Pervasive Sensing technology and linkage technology that is to prevent information loss through the wired, wireless networking and database. Especially, Pervasive Sensing technology is taken as an essential technology that enables user oriented services by recognizing the needs of the users even before the users inquire. There are lots of characteristics of ubiquitous environment through the technologies mentioned above such as ubiquity, abundance of data, mutuality, high information density, individualization and customization. Among them, information density directs the accessible amount and quality of the information and it is stored in bulk with ensured quality through Pervasive Sensing technology. Using this, in the companies, the personalized contents(or information) providing became possible for a target customer. Most of all, there are an increasing number of researches with respect to recommender systems that provide what customers need even when the customers do not explicitly ask something for their needs. Recommender systems are well renowned for its affirmative effect that enlarges the selling opportunities and reduces the searching cost of customers since it finds and provides information according to the customers' traits and preference in advance, in a commerce environment. Recommender systems have proved its usability through several methodologies and experiments conducted upon many different fields from the mid-1990s. Most of the researches related with the recommender systems until now take the products or information of internet or mobile context as its object, but there is not enough research concerned with recommending adequate store to customers in a ubiquitous environment. It is possible to track customers' behaviors in a ubiquitous environment, the same way it is implemented in an online market space even when customers are purchasing in an offline marketplace. Unlike existing internet space, in ubiquitous environment, the interest toward the stores is increasing that provides information according to the traffic line of the customers. In other words, the same product can be purchased in several different stores and the preferred store can be different from the customers by personal preference such as traffic line between stores, location, atmosphere, quality, and price. Krulwich(1997) has developed Lifestyle Finder which recommends a product and a store by using the demographical information and purchasing information generated in the internet commerce. Also, Fano(1998) has created a Shopper's Eye which is an information proving system. The information regarding the closest store from the customers' present location is shown when the customer has sent a to-buy list, Sadeh(2003) developed MyCampus that recommends appropriate information and a store in accordance with the schedule saved in a customers' mobile. Moreover, Keegan and O'Hare(2004) came up with EasiShop that provides the suitable tore information including price, after service, and accessibility after analyzing the to-buy list and the current location of customers. However, Krulwich(1997) does not indicate the characteristics of physical space based on the online commerce context and Keegan and O'Hare(2004) only provides information about store related to a product, while Fano(1998) does not fully consider the relationship between the preference toward the stores and the store itself. The most recent research by Sedah(2003), experimented on campus by suggesting recommender systems that reflect situation and preference information besides the characteristics of the physical space. Yet, there is a potential problem since the researches are based on location and preference information of customers which is connected to the invasion of privacy. The primary beginning point of controversy is an invasion of privacy and individual information in a ubiquitous environment according to researches conducted by Al-Muhtadi(2002), Beresford and Stajano(2003), and Ren(2006). Additionally, individuals want to be left anonymous to protect their own personal information, mentioned in Srivastava(2000). Therefore, in this paper, we suggest a methodology to recommend stores in U-market on the basis of ubiquitous environment not using personal information in order to protect individual information and privacy. The main idea behind our suggested methodology is based on Feature Matrices model (FM model, Shahabi and Banaei-Kashani, 2003) that uses clusters of customers' similar transaction data, which is similar to the Collaborative Filtering. However unlike Collaborative Filtering, this methodology overcomes the problems of personal information and privacy since it is not aware of the customer, exactly who they are, The methodology is compared with single trait model(vector model) such as visitor logs, while looking at the actual improvements of the recommendation when the context information is used. It is not easy to find real U-market data, so we experimented with factual data from a real department store with context information. The recommendation procedure of U-market proposed in this paper is divided into four major phases. First phase is collecting and preprocessing data for analysis of shopping patterns of customers. The traits of shopping patterns are expressed as feature matrices of N dimension. On second phase, the similar shopping patterns are grouped into clusters and the representative pattern of each cluster is derived. The distance between shopping patterns is calculated by Projected Pure Euclidean Distance (Shahabi and Banaei-Kashani, 2003). Third phase finds a representative pattern that is similar to a target customer, and at the same time, the shopping information of the customer is traced and saved dynamically. Fourth, the next store is recommended based on the physical distance between stores of representative patterns and the present location of target customer. In this research, we have evaluated the accuracy of recommendation method based on a factual data derived from a department store. There are technological difficulties of tracking on a real-time basis so we extracted purchasing related information and we added on context information on each transaction. As a result, recommendation based on FM model that applies purchasing and context information is more stable and accurate compared to that of vector model. Additionally, we could find more precise recommendation result as more shopping information is accumulated. Realistically, because of the limitation of ubiquitous environment realization, we were not able to reflect on all different kinds of context but more explicit analysis is expected to be attainable in the future after practical system is embodied.