• Title/Summary/Keyword: 무작위 실험 연구

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Flash-aware Page Management Policy of the Mobile DBMS for Incremental Map Update (점진적 맵 업데이트를 위한 모바일 DBMS의 플래시메모리 페이지 관리 기법)

  • Min, Kyoung Wook;Choi, Jeong Dan;Kim, Ju Wan
    • Spatial Information Research
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    • v.20 no.5
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    • pp.67-76
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    • 2012
  • Recently the mobile DBMS (Database Management System) is popular to store and manage large data in a mobile device. Especially, the research and development about mobile storage structure and querying method for navigation map data in a mobile device have been performed. The performance of the mobile DBMS in which random data accesses are most queries if the NAND flash memory is used as storage media of the DBMS is degraded. The reason is that the performance of flash memory is good in writing sequentially but bad in writing randomly as the features of the NAND flash memory. So, new storage structure and querying policies of the mobile DBMS are needed in the mobile DBMS in which a flash memory is used as storage media. In this paper, we have studied the policy of the database page management to enhance the performance of the frequent random update and applied this policy to the navigation-specialized mobile DBMS which supports incremental map update. And also we have evaluated the performance of this policy by experiments.

Q-factor Estimation of Seismic Trace Including Random Noise using Peak Frequency-Shift Method (무작위 잡음이 포함된 탄성파 트레이스로부터 Peak Frequency-Shift 방법을 이용한 Q-factor 추정)

  • Kwon, Junseok;Chung, Wookeen;Ha, Jiho;Shin, Sungryul
    • Geophysics and Geophysical Exploration
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    • v.21 no.1
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    • pp.54-60
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    • 2018
  • The data acquired from seismic exploration can be used to detect the existence of oil and gas resources through appropriate processing and interpretation. The seismic attributes indicating the existence of resources are extracted from amplitude information, where the Q-factor representing intrinsic attenuation plays an useful role of hydrocarbon indicator. So, the accuracy of Q-factor estimation is very important to investigate the existence of resources. In this study, we calculated the Q-factor and analyzed the error rate through a numerical example. To mimic real data, random noise was added to the synthetic data. With the noise-added data, the Q-factor was estimated and the error rate was analyzed by using the spectral ratio method (SRM) and peak frequency shift method (PFSM). Both methods provided a relatively accurate Q-factor when the signal-to-noise ratio was 90 dB. However, the peak frequency shift method (PFSM) produced better results than the spectral ratio method (SRM) as the level of random noise increased.

The Effect of Cushion Insole on the Flexibility and Exercise Ability of Lumbar Spinal Stenosis (쿠션인솔이 요추 척추관협착증 환자의 유연성 및 운동능력에 미치는 영향)

  • Kim, Hyun Taeg;Moon, Sang Ho;Kim, Kyung Chul;Kwon, Byong An
    • Journal of Digital Convergence
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    • v.17 no.1
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    • pp.423-432
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    • 2019
  • The purpose of this study was to investigate the effect of cushion insole on lumbar flexibility and motor fitness in patients with lumbar spinal stenosis. 26 patients with lumbar spinal stenosis were randomly assigned to the experimental group 13 and the control group 13. Volunteers were allowed to wear cushioned insoles for two hours a day for six weeks. The experimental group was 8 mm and the control group was 4 mm, wearing a cushion insole as a blinded experiment. There was a significant increase(p<0.05) in the flexion test of the experimental group ($3.38{\pm}3.12$), but not statistically significant in the other tests(p>0.05). In conclusion, cushion insole was not suitable for intervention for lumbar spinal stenosis. There is a need to study the height and material of the insoles in the future.

Intervention of Virtual Reality of Adult Nursing Practicum for Nursing Students: A Systematic Review (간호대학생의 성인간호실습 가상현실 교육 중재: 체계적 고찰)

  • Kim, Hyun Kyoung;Ko, Eun Jung
    • The Journal of the Convergence on Culture Technology
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    • v.8 no.6
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    • pp.373-380
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    • 2022
  • This study explored the effectiveness of virtual reality education interventions for nursing students in adult nursing practicum. This systematic review extracted intervention methods, research topics, outcome variables, and evidence synthesis of effectiveness. Seven studies were extracted from the databases of PubMed, Cochrane Library, EMBASE, and RISS. This study showed effects on knowledge, performance, attitude, critical thinking, self-efficacy, information assessment ability, problem-solving ability, self-confidence, and efficiency of nursing students. Therefore, virtual reality educational intervention contribute to enhance the competencies in adult nursing practicum.

Current Concepts of Osteochondral Lesions of Talus (거골 체 골연골 병변에 대한 최신 지견)

  • Park, Y.W.
    • Journal of Korean Orthopaedic Sports Medicine
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    • v.6 no.1
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    • pp.27-32
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    • 2007
  • 골연골 병변에 관한 논문들을 살펴본 결과, 연구 방법, 각기 다른 치료 방법에 의해 얻어진 결과가 상당한 가변성을 보였다. 현 시점에서 골연골편 제거술 및 병변의 변연 절제와 천공술 그리고 자가 골연골 이식술 등이 가장 널리 이용되고 있으며 효과적인 치료 방법으로 사료된다. 그러나 가장 적절한 치료 수단이 무엇인지에 대한 명확한 결론을 유추하기 위해서는 무작위 임상 실험과 동일한 연구 방법에 의한 결과 측정의 비교가 우선되어져야 할 것으로 사료된다.

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Adaptive English Context-Sensitive Spelling Error Correction Techniques for Language Environments (언어 사용환경에 적응적인 영어 문맥의존 철자오류 교정 기법)

  • Kim, Minho;Jin, Jingzhi;Kwon, Hyuk-Chul
    • Annual Conference on Human and Language Technology
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    • 2015.10a
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    • pp.133-136
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    • 2015
  • 문서 교정기에서 문맥의존 철자오류를 교정하는 방법은 크게 규칙을 이용한 방법과 통계 정보를 이용한 방법으로 나뉜다. 한국어와 달리 영어는 오래전부터 통계 모형에 기반을 둔 문맥의존 철자오류 교정 연구가 활발히 이루어졌다. 그러나 대부분 연구가 문맥의존 철자오류 교정 문제를 특정 어휘 쌍을 이용한 분류 문제로 간주하기 때문에 실제 응용에는 한계가 있다. 또한, 대규모 말뭉치에서 추출한 통계 정보를 이용하지만, 통계 정보 자체에 오류가 있을 경우를 고려하지 않았다. 본 논문에서는 텍스트에 포함된 모든 단어에 대하여 문맥의존 철자오류 여부를 판단하고, 해당 단어가 오류일 경우 대치어를 제시하는 영어 문맥의존 철자오류 교정 기법을 제안한다. 또한, 통계 정보의 오류가 문맥의존 철자오류 교정에 미치는 영향과 오류 발생률의 변화가 철자오류 검색과 교정의 정확도와 재현율에 미치는 영향을 분석한다. 구글 웹데이터에서 추출한 통계 정보를 바탕으로 통계 모형을 구성하고 평가를 위해 브라운 말뭉치에서 무작위로 2,000문장을 추출하여 무작위로 문맥의존 철자오류를 생성하였다. 실험결과, 문맥의존 철자오류 검색의 정확도와 재현율은 각각 98.72%, 95.79%였으며, 문맥의존 철자오류 교정의 정확도와 재현률은 각각 71.94%, 69.81%였다.

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A Study on Improvement of Buffer Cache Performance for File I/O in Deep Learning (딥러닝의 파일 입출력을 위한 버퍼캐시 성능 개선 연구)

  • Jeongha Lee;Hyokyung Bahn
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.24 no.2
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    • pp.93-98
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    • 2024
  • With the rapid advance in AI (artificial intelligence) and high-performance computing technologies, deep learning is being used in various fields. Deep learning proceeds training by randomly reading a large amount of data and repeats this process. A large number of files are randomly repeatedly referenced during deep learning, which shows different access characteristics from traditional workloads with temporal locality. In order to cope with the difficulty in caching caused by deep learning, we propose a new sampling method that aims at reducing the randomness of dataset reading and adaptively operating on existing buffer cache algorithms. We show that the proposed policy reduces the miss rate of the buffer cache by 16% on average and up to 33% compared to the existing method, and improves the execution time by up to 24%.

A Study on relevance criteria of retrieved documents according to the research stage (연구진행정도에 따른 검색문헌의 적합평가기준 연구)

  • 김홍렬;이두영
    • Proceedings of the Korean Society for Information Management Conference
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    • 1999.08a
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    • pp.5-8
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    • 1999
  • 본 연구는 이용자 지향적인 측면에서 적합문헌평가에 대한 다양한 기준들을 확인하고, 실제 연구자들이 그들의 연구 진행정도에 따라서 적합문헌을 평가하는 기준과 문헌의 적합여부평가에 인식적인 차이를 나타내는지를 밝히는데 그 목적이 있다. 이를 위하여 본 연구에서는 문헌조사연구 방법과 실험연구방법을 병행하여 사용하였다. 먼저 문헌조사 연구를 통하여 본 연구문제의 이론적 배경과 이용자 지향적 적합문헌 평가기준들을 종합적으로 분석하고, 실험에 사용할 평가기준들을 도출하였으며, 실험연구에서는 실제 연구문제를 가지고 있는 5명의 이용자를 무작위로 선정하여 그들의 연구진행 정도에 따른 적합평가기준을 시작(정보입수자각, 관련정보를 수집하는 최초의 단계), 진행(수집정보를 정리하고 초점을 형성, 집필의 시작단계), 완성단계(본격적인 집필과정으로 인용문헌들 결정하는 단계)로 나누어 조사하였다.

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A Statistical Testing of the Consistency Index in Analytic Hierarchy Process (계층적 의사결정론에서 일관성 지수에 대한 통계적 검정)

  • Lee, Jong Chan;Jhun, Myoungshic;Jeong, Hyeong Chul
    • The Korean Journal of Applied Statistics
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    • v.27 no.1
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    • pp.103-114
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    • 2014
  • Significant research has been devoted to the consistency index of the Analytic Hierarchy Process(AHP) from several perspectives. Critics of the consistency index in AHP state that the critical value of consistency index depends on an average of the random index based simulation study using a 9 scale comparison matrix. We found that the distribution of the consistency index followed the skew distribution according to the dimension of the comparison matrix based on a simulation study with a 9 scale comparison matrix. From the simulation study, we suggest a consistency index quantile table to assist the decision-making process in AHP; in addition, we can approximate the distribution of the consistency index to the gamma distribution under the limited assumptions.

Development of a Prediction Model for the Mechanical Properties of Polypropylene Composites Reinforced by Talc and Short Glass Fibers (탈크 및 유리단섬유로 강화된 폴리프로필렌 복합재료의 기계적 물성 예측 모델 개발)

  • Kim, Soon;Son, Dongil;Choi, Donghyuk;Jeong, Inchan;Park, Young-Bin;Kim, Sung Youb
    • Composites Research
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    • v.26 no.4
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    • pp.245-253
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    • 2013
  • In this paper, we developed a theoretical model which is able to predict the tensile strength and elastic modulus of hybrid composites reinforced by two types of randomly distributed discontinuous reinforcements. For this, we considered two known models; One is a prediction model based on the assumption that the composite is reinforced by two types of well aligned continuous reinforcements. The other is a statistical model for the composite which is reinforced by only one type of randomly distributed discontinuous reinforcements. In order to evaluate the validity of accuracy of our prediction model, we measured the strength and elastic modulus of polypropylene hybrid composite reinforced by talc and short glass fiber. We found that the present model drastically enhances the accuracy of strength prediction compared to an existing model, and predicts the elastic modulus within the same order with experimentally measured values.