• 제목/요약/키워드: System Acceptance

검색결과 1,100건 처리시간 0.033초

해양생태독성평가를 위한 표준시험방법 개발에 관한 연구 (Establishment of Standard Methods for Marine Ecotoxicological Test)

  • 박경수;이승민;한태준;이정석
    • 한국해양학회지:바다
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    • 제13권2호
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    • pp.106-111
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    • 2008
  • 해양생태독성평가를 위한 공정시험방법으로서 해양생태계의 분해자, 기초생산자 및 소비자를 대표하는 6개 생물군을 이용하여 각각의 생물에 대한 생태독성시험용 표준시험방법(standard methods)을 개발 또는 정립하였다. 본 시험방법은 미환경보호국, 국제기구 및 유럽국가의 표준시험방법을 참고하였으며, 독성시험에 사용되는 표준시험생물은 우리나라에 서식하는 해양성 또는 광염성 생물(euryhaline species)로 선정하였다. 각 시험방법은 표준시험생물의 배양 및 사육, 시험방법 및 과정, 시험의 재현성 및 적합도 기준 등을 포함한다. 표준시험생물은 총 9종으로서 해산발광박테리아(Vibrio fischeri), 해산규조류(Skeletonema costatum), 녹조구멍갈파래(Ulva pertusa), 해산윤충류(Brachionus plicatilis), 저서요각류(Tigriopus japonicus), 저서단각류 2종(Mandibulophoxus mai and Monocorophium acherusicum) 및 어류 2종(Oryzias latipes and Paralichthys olivaceus)을 포함한다. 표준시험생물은 해양생태계의 기초생산자, 분해자 및 소비자를 대표하며, 생태독성 시험시 각 영양 단계별 최소 1종을 포함하는 총 3종의 "battery test"를 권장한다.

감마핵종 In-Situ 측정 연구 동향 분석 및 방사능 측정 효율 민감도 평가 (In-Situ Gamma Spectrometry Research Analysis and Radiation Efficiency Sensitivity Evaluation)

  • 라현준;김혁재;이성연;곽민우;김광표
    • 방사선산업학회지
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    • 제17권1호
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    • pp.1-9
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    • 2023
  • Since a large amount of radioactive waste is expected to be generated due to permanent shutdown of many nuclear power plants, it is necessary to prepare efficient management methods for radioactive waste. Therefore, there is a need for a based study to apply the In-Situ gamma spectrometry, which can simplify the measurement procedure. The purpose of this study is to analyze research cases of In-Situ gamma spectrometry and to analyze the sensitivity of measurement according to influencing factors on In-Situ gamma spectrometry. Research cases of five institutions, including the CERN and the Imperial College Reactor Centre (ICRC), were selected as the institutions to be investigated. Research on the In-Situ gamma spectrometry was conducted on the satisfaction of the acceptance criteria for radioactive waste and the analysis of residual radioactivity in the site. In-Situ Objective Counting System (ISOCS) was used as a major measuring device. Sampling and computer code were used to verify the analysis results. For evaluation of measuring sensitivity according to influencing factors on In-Situ gamma spectrometry, the thickness of the measurement target, the distance between the detector and the target, the angle of the collimator, and the contamination location were performed using ISOCS's Geometry Composer. In every case, based on 122 keV, the efficiency decreased as the energy increased in the high energy region, and the efficiency decreased as the energy decreased in the low energy region. As the target thickness increased, the efficiency decreased, and as the distance between target and detector increased, the efficiency decreased. As the distance between contamination and detector increased, the efficiency decreased, and as the angle of the collimator increased, the measurement efficiency increased. However, when simulating the measurement situation using Geometry Composer, the background is not considered, and the probability of incident in the background increases as the angle increases, so further research needs to be conducted in consideration of these. This study can be utilized when applying the In-Situ gamma spectrometry of radioactive waste clearance in the future.

해상풍력발전단지 대안설정 방법 및 평가에 관한 연구 - 해외 사례를 중심으로 - (A Study on the Alternative Establishment Method and Evaluation of Offshore Wind Farms - Focusing on Overseas Cases -)

  • 김진오;우경숙;김진표
    • 환경영향평가
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    • 제33권4호
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    • pp.164-174
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    • 2024
  • 최근 국내에서도 많은 해상풍력발전 사업계획과 환경영향평가가 이루어지고 있다. 하지만 육상풍력발전과는 다른 특성을 가지고 있음에도 불구하고 이에 적합한 대안설정 및 평가 방법이 부족한 실정이다. 이에 따라 본 연구는 해외의 가이드라인 및 사례 분석을 통해 국내 실정에 적합한 대안설정 및 평가 방법에 대한 시사점을 도출하고자 하였다. 분석의 결과를 통해 해상풍력발전 대안설정 및 평가 방법의 프로세스를 살펴볼 수 있었으며 이를 통한 세부적인 고려사항 및 방법론을 알 수 있었다. 아직 해외에서도 대안설정 및 평가에 관한 방법론이 명확하지 않고 육상풍력발전에 사용하던 방법론을 개량하고 발전시켜 사용하고 있었다. 국내에도 이러한 해상풍력사업의 대안설정 및 평가를 위한 체계마련이 필요하며 합리적이고 효율적으로 수행하기 위해서 다양한 분야에서의 연구가 필요하다. 국내 해상풍력발전사업의 성공적인 추진을 위해서는 해외 사례에서 도출된 시사점을 반영한 관련 연구의 촉진과 함께, 환경적, 사회적 수용성을 높이기 위한 지속적인 노력이 필요할 것으로 생각된다.

개인용 클라우드 서비스에 대한 중국 사용자의 지속적 사용의도에 관한 실증 연구 (An Empirical Analysis on the Persistent Usage Intention of Chinese Personal Cloud Service)

  • 우학흠;수아이니 수라;안종창
    • 인터넷정보학회논문지
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    • 제16권3호
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    • pp.79-93
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    • 2015
  • IT기술의 고속 발전에 따라 사용자들이 기술을 사용하는 방식에 큰 변화가 생기고 있다. 전통적인 서비스 응용과 저효율의 데이터를 처리하는 방식은 사용자의 요구를 만족할 수 없다. 사용자들이 데이터의 중요성을 알게 되었고, 빅 데이터에 관한 처리와 저장기술은 오늘날의 인터넷 회사의 주요 연구방향이 되고 있다. 115 네트워크 디스크는 중국에서 폭넓게 사용되기 시작하였고 각 인터넷 회사들은 클라우드 서비스 시장을 쟁탈하는 싸움에 참여하기 시작하였다. 중국의 클라우드 서비스는 아직도 스토리지 서비스 위주이지만, 이 기능을 바탕으로 확장하는 서비스 내용도 사용자의 인정을 받고 있으며, 사용자들이 이러한 새로운 서비스 방식을 사용하는 것을 시도하고 있다. 그래서 어떻게 하면 사용자들이 지속적으로 클라우드 서비스를 사용 할 것인지에 관한 연구방향이 더욱 필요해 졌다. 하나의 전통적인 정보 시스템에 대해, 학자들은 대개 TAM(Technology acceptance model)모형과 통계학을 결합하여 이 시스템에 대한 사용자들의 태도를 분석하고 검증한다. 하지만 기본적인 TAM모형은 날이 갈수록 방대해지는 시스템의 규모를 만족 할 수 없게 되었다. 따라서 TAM모형에 대한 적당한 확장과 조절이 필요하게 되었다. 본 연구는 중국의 개인용 클라우드 서비스 사용자의 지속적인 사용의도에 영향을 미치는 요인에 관한 실증분석을 목표로 브랜드 영향력, 하드웨어 환경 등 외부 변수를 추가하고, 중국 클라우드 사용자를 대상으로 설문 조사를 진행했으며, 본 논문에서 분석을 통해 수정된 모형에 관한 가설을 검증하였다. 본 연구는 주로 중국의 4개 주요 도시의 210명의 클라우드 서비스 사용자를 대상으로 인터넷 설문 조사를 실행하였다. 설문 데이터를 통해 3개의 외부 변수에 대한 분석을 진행하였고, 이 3개의 외부 변수를 세분화하고 외부요소에 영향을 주는 주요 원인을 찾아냈다. 이를 바탕으로 개인 클라우드 서비스 사용자들이 서비스를 지속적으로 사용 할 수 있는 태도를 강화 할 수 있는 것에 유용한 의견을 제시하였다. 이러한 의견들은 중국사용자들을 대상으로 하는 주요 서비스를 제공 하는 회사에게 향후 서비스 방향을 참고할 수 있는 정보를 제공한다.

업무성과에 영향을 주는 업무용 모바일 어플리케이션의 주요 요인에 관한 연구 (An Empirical Study on the Influencing Factors of Perceived Job Performance in the Context of Enterprise Mobile Applications)

  • 정성훈;김기민
    • Asia pacific journal of information systems
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    • 제24권1호
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    • pp.31-50
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    • 2014
  • The ubiquitous accessibility of information through mobile devices has led to an increased mobility of workers from their fixed workplaces. Market researchers estimate that by 2016, 350 million workers will be using their smartphones for business purposes, and the use of smartphones will offer new business benefits. Enterprises are now adopting mobile technologies for numerous applications to increase their operational efficiency, improve their responsiveness and competitiveness, and cultivate their innovativeness. For these reasons, various organizational aspects concerning "mobile work" have received a great deal of recent attention. Moreover, many CIOs plan to allocate a considerable amount of their budgets mobile work environments. In particular, with the consumerization of information technology, enterprise mobile applications (EMA) have played a significant role in the explosive growth of mobile computing in the workplace, and even in improving sales for firms in this field. EMA can be defined as mobile technologies and role-based applications, as companies design them for specific roles and functions in organizations. Technically, EMA can be defined as business enterprise systems, including critical business functions that enable users to access enterprise systems via wireless mobile devices, such as smartphones or tablets. Specifically, EMA enables employees to have greater access to real-time information, and provides them with simple features and functionalities that are easy for them to complete specific tasks. While the impact of EMA on organizational workers' productivity has been given considerable attention in various literatures, relatively little research effort has been made to examine how EMA actually lead to users' job performance. In particular, we have a limited understanding of what the key antecedents are of such an EMA usage outcome. In this paper, we focus on employees' perceived job performance as the outcome of EMA use, which indicates the successful role of EMA with regard to employees' tasks. Thus, to develop a deeper understanding of the relationship among EMA, its environment, and employees' perceived job performance, we develop a comprehensive model that considers the perceived-fit between EMA and employees' tasks, satisfaction on EMA, and the organizational environment. With this model, we try to examine EMA to explain how job performance through EMA is revealed from both the task-technology fit for EMA and satisfaction on EMA, while also considering the antecedent factors for these constructs. The objectives of this study are to address the following research questions: (1) How can employees successfully manage EMA in order to enhance their perceived job performance? (2) What internal and/or external factors are important antecedents in increasing EMA users' satisfaction on MES and task-technology fit for EMA? (3) What are the impacts of organizational (e.g. organizational agility), and task-related antecedents (e.g., task mobility) on task-technology fit for EMA? (4) What are the impacts of internal (e.g., self-efficacy) and external antecedents (e.g., system reputation) for the habitual use of EMA? Based on a survey from 254 actual employees who use EMA in their workplace across industries, our results indicate that task-technology fit for EMA and satisfaction on EMA are positively associated with job performance. We also identify task mobility, organizational agility, and system accessibility that are found to be positively associated with task-technology fit for EMA. Further, we find that external factor, such as the reputation of EMA, and internal factor, such as self-efficacy for EMA that are found to be positively associated with the satisfaction of EMA. The present findings enable researchers and practitioners to understand the role of EMA, which facilitates organizational workers' efficient work processes, as well as the importance of task-technology fit for EMA. Our model provides a new set of antecedents and consequence variables for a TAM involving mobile applications. The research model also provides empirical evidence that EMA are important mobile services that positively influence individuals' performance. Our findings suggest that perceived organizational agility and task mobility do have a significant influence on task-technology fit for EMA usage through positive beliefs about EMA, that self-efficacy and system reputation can also influence individuals' satisfaction on EMA, and that these factors are important contingent factors for the impact of system satisfaction and perceived job performance. Our findings can help managers gauge the impact of EMA in terms of its contribution to job performance. Our results provide an explanation as to why many firms have recently adopted EMA for efficient business processes and productivity support. Our findings additionally suggest that the cognitive fit between task and technology can be an important requirement for the productivity support of EMA. Further, our study findings can help managers in formulating their strategies and building organizational culture that can affect employees perceived job performance. Managers, thus, can tailor their dependence on EMA as high or low, depending on their task's characteristics, to maximize the job performance in the workplace. Overall, this study strengthens our knowledge regarding the impact of mobile applications in organizational contexts, technology acceptance and the role of task characteristics. To conclude, we hope that our research inspires future studies exploring digital productivity in the workplace and/or taking the role of EMA into account for employee job performance.

지리적 표시제도의 의의 및 보호체제 연구 (A Study on the Concept and Protection System for the Geographical Indication)

  • 고용부
    • 한국항만경제학회지
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    • 제23권3호
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    • pp.165-184
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    • 2007
  • 본 연구에서는 한 EU FTA 협상에서 중요이슈가 되고 있는 지적 재산권으로서의 지리적 표시제에 대한 의의 및 보호체계를 검토 연구했다. 지리적 표시는 상품의 품질 등이 지리적 특성과 연계된 지리적 명칭을 지적재산권으로 보호해주는 제도이다. 19C 후반부터 이에 대한 보호노력이 여러형태로 계속되어 오다가 드디어 WTO TRIPS 협정 상에 지적 재산권 보호대상으로 규정되었고, 이에 따라 지리적표시는 양자 규범 복수규범 내지 임의 규범에서 다자 규범 의무 규범으로 발전 된 것이다. 지리적 표시는 이같이 다자규범으로 자리 잡은 후에도 특히 EU를 주도로 하여 DDA 협상에서 계속 확대 개선을 위한 논의가 활발히 이루어지고 있다. 지리적표시보호에 대한 각국의 체계 및 형태는 유사하나 크게는 EU형과 미국형이 있다. 특히 EU는 지리적 표시가 품질정책 및 공동농업정책의 근간이 되어있고 현재 남부 공업국가의 품목들이 대부분을 점하고 있는 5,000여개의 지리적 표시가 주류 및 가공식품을 중심으로 등록되어 있으며 이에 따라 지리적표시의 국제적 보호규범체계의 정립 및 확대에서 항상 주도적 입장을 유지하고 있다. 우리나라는 1997년 7월부터 농수산 품질관리법에 의한 등록제를 마련했고 2004 7월에는 상표법에 의한 지리적표시 단체장 등록제도를 도입 운영하고 있으며 이에 기초하여 40여개의 품목들이 지리적 표시품목으로 등록되어있다. 한국과 EU 간의 지리적 표시에 관련한 협상에서는 EU 측의 적극적 상호인정 요구가 추진이 예상되고 이에 따라 우리의 대응이나 전략여하가 문제된다. 물론 EU는 그 보호가 발전되어 있고 보호등록이 많으며 그것이 농업정책의 개혁과 고품질 농산물의 화대 정책의 근간을 이루고 있다는 점에서 적극적 상호인정이 쉽지 않다. 그러나 여기서 우리는 장기적 구도로 본다면 지리적 표시 보호의 상호 인정을 회피나 무조건적 거부보다는 긍정적 단계적 측면에서 조심스럽게 접근하되 국제적 규범과 조화하면서도 후속적 관리와 대응에 철저한 이른바 전략적 수용과 대비를 고려할 수 있을 것이다. 특히 우리의 지리적표시제는 우리 농산물만의 특성에 따른 품질 향상과 경쟁력 강화 및 고 부가치 전략 구축에 결정적이고도 중요한 요인이 될 수 있다는 강점도 있다는 점이다. 정부와 농업인의 지혜를 모아 지리적 표시로 등록된 40여개 품목에 대한 지속적 품질개선은 물론 타 농산물 및 식품의 지속적 표시확대 그리고 특성화에로의 개발전략 등으로 EU시장에 과감히 진출할 경우 유럽시장에의 우리의 접근성 창출성이 크게 증폭 될 것이다.

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국제항공화물운송계약(國際航空貨物運送契約)의 법률관계(法律關係) -화주(貨主)의 권리의무(權利義務)를 중심(中心)으로- (Legal Relations of the Contract of International Carriage of Goods by Air)

  • 이강빈
    • 항공우주정책ㆍ법학회지
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    • 제1권
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    • pp.193-222
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    • 1989
  • The purpose of this study is to review the rights and duties of cargo owners, the party to the contract of international carriage of goods by air under the Warsaw Convention System and the IATA conditions. It is generally known that air freight is the most-cost mode of transportation. However, should there be considerations of total distribution cost, the use of air freight leads exporters to be advantageous in physical distribution. The Warsaw Convention System defined and limited the rights and duties of cargo owners and air carriers paticipating in the international carriage of goods, but it does not regulate every aspect of air transportation. Therefore, the unregulated parts are governed by national laws and by individual contracts of carriage. The International Air Transport Association(lATA), a worldwide organization of airlines, has formulated model conditions of contract for the carriage of cargo. These models are not uniformly followed but they serve as a basis for many of the individual standard form of contracts prepared by air carriers. The contract of air carriage of goods is a contract of adhesion, 'the consignor recognizing and accepting the conditions laid down by the carrier'. There are consignors and carriers as the parties to the contract of international carriage of goods. In addition to his basic right, implied in Warsaw Convention Article 18 and 19, to require devery of the goods in good condition and at the date agreed upon, the consignor has the right to dispose the goods in the course of the journey up to the moment when the consignee is entitled to require delivery. If it is impossible to carry out the orders of the consignor, the carrier must so inform him forthwith. The right conferred on the consignor ceases at the moment when that of the consignee begins in accordance with Warsaw Convention Article 13. Nevertheless, if the consignee declines to accept the air waybill or the goods, or if he cannot be communicated with, the consignor resumes his right of disposition. Unless it is otherwise agreed, it is the duty of the carrier to give notice to the consignee as soon as the goods arrive. The consignee is entitled, on arrival of the goods at the place of destination, to require the carrier to hand over to him the air waybill and to deliver the goods to him, on payment of the charges due and on complying with the conditions of carriage set out in the air waybill. The air waybill is supposed to be made out by the consignor. If the carrier makes it out, he is deemed, subject to proof to the contrary, to have done so on behalf of the consignor, whether there is one air waybill or several, each must be made out in three original parts. The first is for the carrier, the second is for the consignee, and the the third is handed to the consignor when the shipment has been accepted. The consignor is responsible for the correctness of the particulars and statement concerning the cargo appearing in the air waybill. Each of the original parts of the air waybill has evidential value and possession of his part is a condition for the exercise by the consignor or consignee of his rights under the contract of carriage. Hague Protocol set forth in Article 9 that nothing in this. Convention prevents the issue of a negotiable air waybill, but Montreal Additional Protocol No. 4 deleted this article. All charges applicable to a shipment are payable in cash at the time of acceptance thereof by the carrier in case of a prepaid shipment or at the time of delivery thereof by the carrier in case of a collect shipment. The carrier shall have lien the cargo for unpaid charges and, in the event of non-payment thereof, shall have the right to dispose of the cargo at public or private sale and pay itself out of the proceeds of such sale any and all such amounts. In conclusion, the Warsaw Convention System has the character of ambiguity in various respects, not only in the part of the forms of documents but also in conditions of contract. Accordingly, the following propositions might be considered: (1) If the carrier does not obey the orders of the consignor for the disposition of the goods without proper reasons, he will be liable strictly for any damage which may be caused thereby to the cargo owner. The special agreement and carrier's conditions of carriage which limit unreasonably the consignor's right of disposition of the goods will be nullified. (2) The instrument of the Warsaw Convention System which is not yet in force(Montreal Additional Protocol No. 4) would considerably simplfy the processing and keeping of computerized records of the carriage. Until this instrument enters into force, the airlines will be faced with practical problems preventing them to substitute computerized data processing techniques for the formal issuance of the documents. Accordingly, Montreal Additional Protocol No. 4 should become effective as soon as posisble. From a practical point of view in the international trade, the issuance of negotiable air waybill should be permitted for the security of the bank.

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국제전자정보거래(國際電子情報去來)에 관한 입법동향(立法動向) (Recent Developments in Law of International Electronic Information Transactions)

  • 허해관
    • 무역상무연구
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    • 제23권
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    • pp.155-219
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    • 2004
  • This paper focuses on two recent legislative developments in electronic commerce: the "Uniform Computer Information Transactions Act" ("UCITA") of USA and the "preliminary draft convention on the use of data message in [international trade] [the context of international contracts]" ("preliminary draft Convention") of UNCITRAL. UCITA provides rules contracts for computer information transactions. UCITA supplies modified contract formation rules adapted to permit and to facilitate electronic contracting. UCITA also adjusts commonly recognized warranties as appropriate for computer information transactions; for example, to recognize the international context in connection with protection against infringement and misappropriation, and First Amendment considerations involved with informational content. Furthermore, UCITA adapts traditional rules as to what is acceptable performance to the context of computer information transactions, including providing rules for the protection of the parties concerning the electronic regulation of performance to clarify that the appropriate general rule is one of material breach with respect to cancellation (rather than so-called perfect tender). UCITA also supplies guidance in the case of certain specialized types of contracts, e.g., access contracts and for termination of contracts. While for the most part carrying over the familiar rules of Article 2 concerning breach when appropriate in the context of the tangible medium on which the information is fixed, but also adapting common law rules and rules from Article 2 on waiver, cure, assurance and anticipatory breach to the context of computer information transactions, UCITA provides a remedy structure somewhat modeled on that of Article 2 but adapted in significant respects to the different context of a computer information transaction. For example, UCITA contains very important limitations on the generally recognized common law right of self-help as applicable in the electronic context. The UNCITRAL's preliminary draft Convention applies to the use of data messages in connection with an existing or contemplated contract between parties whose places of business are in different States. Nothing in the Convention affects the application of any rule of law that may require the parties to disclose their identities, places of business or other information, or relieves a party from the legal consequences of making inaccurate or false statements in that regard. Likewise, nothing in the Convention requires a contract or any other communication, declaration, demand, notice or request that the parties are required to make or choose to make in connection with an existing or contemplated contract to be made or evidenced in any particular form. Under the Convention, a communication, declaration, demand, notice or request that the parties are required to make or choose to make in connection with an existing or contemplated contract, including an offer and the acceptance of an offer, is conveyed by means of data messages. Also, the Convention provides for use of automated information systems for contract formation: a contract formed by the interaction of an automated information system and a person, or by the interaction of automated information systems, shall not be denied on the sole ground that no person reviewed each of the individual actions carried out by such systems or the resulting agreement. Further, the Convention provides that, unless otherwise agreed by the parties, a contract concluded by a person that accesses an automated information system of another party has no legal effect and is not enforceable if the person made an error in a data message and (a) the automated information system did not provide the person with an opportunity to prevent or correct the error; (b) the person notifies the other party of the error as soon as practicable when the person making the error learns of it and indicates that he or she made an error in the data message; (c) The person takes reasonable steps, including steps that conform to the other party's instructions, to return the goods or services received, if any, as a result of the error or, if instructed to do so, to destroy such goods or services.

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보다 정확한 동적 상황인식 추천을 위해 정확 및 오류 패턴을 활용하여 순차적 매칭 성능이 개선된 상황 예측 방법 (Context Prediction Using Right and Wrong Patterns to Improve Sequential Matching Performance for More Accurate Dynamic Context-Aware Recommendation)

  • 권오병
    • Asia pacific journal of information systems
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    • 제19권3호
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    • pp.51-67
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    • 2009
  • Developing an agile recommender system for nomadic users has been regarded as a promising application in mobile and ubiquitous settings. To increase the quality of personalized recommendation in terms of accuracy and elapsed time, estimating future context of the user in a correct way is highly crucial. Traditionally, time series analysis and Makovian process have been adopted for such forecasting. However, these methods are not adequate in predicting context data, only because most of context data are represented as nominal scale. To resolve these limitations, the alignment-prediction algorithm has been suggested for context prediction, especially for future context from the low-level context. Recently, an ontological approach has been proposed for guided context prediction without context history. However, due to variety of context information, acquiring sufficient context prediction knowledge a priori is not easy in most of service domains. Hence, the purpose of this paper is to propose a novel context prediction methodology, which does not require a priori knowledge, and to increase accuracy and decrease elapsed time for service response. To do so, we have newly developed pattern-based context prediction approach. First of ail, a set of individual rules is derived from each context attribute using context history. Then a pattern consisted of results from reasoning individual rules, is developed for pattern learning. If at least one context property matches, say R, then regard the pattern as right. If the pattern is new, add right pattern, set the value of mismatched properties = 0, freq = 1 and w(R, 1). Otherwise, increase the frequency of the matched right pattern by 1 and then set w(R,freq). After finishing training, if the frequency is greater than a threshold value, then save the right pattern in knowledge base. On the other hand, if at least one context property matches, say W, then regard the pattern as wrong. If the pattern is new, modify the result into wrong answer, add right pattern, and set frequency to 1 and w(W, 1). Or, increase the matched wrong pattern's frequency by 1 and then set w(W, freq). After finishing training, if the frequency value is greater than a threshold level, then save the wrong pattern on the knowledge basis. Then, context prediction is performed with combinatorial rules as follows: first, identify current context. Second, find matched patterns from right patterns. If there is no pattern matched, then find a matching pattern from wrong patterns. If a matching pattern is not found, then choose one context property whose predictability is higher than that of any other properties. To show the feasibility of the methodology proposed in this paper, we collected actual context history from the travelers who had visited the largest amusement park in Korea. As a result, 400 context records were collected in 2009. Then we randomly selected 70% of the records as training data. The rest were selected as testing data. To examine the performance of the methodology, prediction accuracy and elapsed time were chosen as measures. We compared the performance with case-based reasoning and voting methods. Through a simulation test, we conclude that our methodology is clearly better than CBR and voting methods in terms of accuracy and elapsed time. This shows that the methodology is relatively valid and scalable. As a second round of the experiment, we compared a full model to a partial model. A full model indicates that right and wrong patterns are used for reasoning the future context. On the other hand, a partial model means that the reasoning is performed only with right patterns, which is generally adopted in the legacy alignment-prediction method. It turned out that a full model is better than a partial model in terms of the accuracy while partial model is better when considering elapsed time. As a last experiment, we took into our consideration potential privacy problems that might arise among the users. To mediate such concern, we excluded such context properties as date of tour and user profiles such as gender and age. The outcome shows that preserving privacy is endurable. Contributions of this paper are as follows: First, academically, we have improved sequential matching methods to predict accuracy and service time by considering individual rules of each context property and learning from wrong patterns. Second, the proposed method is found to be quite effective for privacy preserving applications, which are frequently required by B2C context-aware services; the privacy preserving system applying the proposed method successfully can also decrease elapsed time. Hence, the method is very practical in establishing privacy preserving context-aware services. Our future research issues taking into account some limitations in this paper can be summarized as follows. First, user acceptance or usability will be tested with actual users in order to prove the value of the prototype system. Second, we will apply the proposed method to more general application domains as this paper focused on tourism in amusement park.

열형광선량계를 이용한 전자선 품질보증 프로그램에 관한 연구 (Quality Assurance Program of Electron Beams Using Thermoluminescence Dosimetry)

  • 라정은;김귀야;정희교;신동오;서태석
    • 한국의학물리학회지:의학물리
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    • 제16권2호
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    • pp.62-69
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    • 2005
  • 본 연구에서는 열형광선량계에 대한 전자선에너지 보정인수를 구하여 이온함을 이용한 물 흡수선량과 상호 비교 분석하여 열형광선량계를 이용한 전자선의 품질보증 프로그램을 개발하고자 한다. 열형광물질은 분말형태인 $^7LiF$을 사용하였고 판독기는 Fimel사의 PCL-3 모델을 사용하였으며 전자선 선량측정에 이용되는 홀더는 PMMA 재질로 제작하였다. 열형광선량계는 선형가속기(Varian CL 2100C)에서 방출되는 전자선 에너지 6, 9, 12, 16, 20 MeV를 이용하여 각 에너지에 해당하는 기준깊이 $Z_{ref}$에 위치시켰으며 물 흡수선량 2 Gy가 되도록 조사하였다 이때 기준선량은 IAEA TRS-398 프로토콜에서 권고하고 있는 절차에 따라 식품의약품안전청에서 교정 받은 Roos형 평행평판형이온함을 사용하여 결정하였다. 열형광선량계의 물 흡수선량을 결정하기 위해 열형광선량계의 교정계수 및 선량 반응도에 대한 보정인수, 퇴색보정인수, 에너지보정인수 등을 산출하였다. 또한 본 연구를 통해 결정된 교정계수 및 각각의 보정인수의 정확도를 검증하기 위해 백지정사(blind test)를 실시하였으며 그 결과, 에너지 9, 16, 20 MeV전자선에서 상대 표준편차가 각각 $2.98\%,\;3.39\%$ 그리고 $0.01\%$로 나타났다 이는 전자선의 허용수준인 $\pm5\%$이내 포함되는 결과로 향후 국내 의료기관에서 사용하고 있는 전자선의 출력 선량측정에 대한 주기적인 품질보증을 위해 열형광선량계가 적극 활용될 것으로 기대한다.

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