• 한국컴퓨터정보학회논문지
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• 제22권2호
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• pp.1-7
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• 2017

Recently, NAND flash memory, which is used as a storage medium, is replacing HDD (Hard Disk Drive) at a high speed due to various advantages such as fast access speed, low power, and easy portability. In order to apply NAND flash memory to a computer system, a Flash Translation Layer (FTL) is indispensably required. FTL provides a number of features such as address mapping, garbage collection, wear leveling, and hot data identification. In particular, hot data identification is an algorithm that identifies specific pages where data updates frequently occur. Hot data identification helps to improve overall performance by identifying and managing hot data separately. MHF (Multi hash framework) technique, known as hot data identification technique, records the number of write operations in memory. The recorded value is evaluated and judged as hot data. However, the method of counting the number of times in a write request is not enough to judge a page as a hot data page. In this paper, we propose hot data identification which considers not only the number of write requests but also the persistence of write requests.

• 한국컴퓨터정보학회논문지
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• 제24권6호
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• pp.1-9
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• 2019

Hard disks, which have long been used as secondary storage in computing systems, are increasingly being replaced by solid state drives (SSDs), due to their relatively fast data input / output speeds and small, light weight. SSDs that use NAND flash memory as a storage medium are significantly different from hard disks in terms of physical operation and internal operation. In particular, there is a feature that data overwrite can not be performed, which causes erase operation before writing. In order to solve this problem, a hot data for frequently updating a data for a specific page is distinguished from a cold data for a relatively non-hot data. Hot data identification helps to improve overall performance by identifying and managing hot data separately. Among the various hot data identification methods known so far, there is a technique of recording consecutive write requests by using a Bloom filter and judging the values by hot data. However, the Bloom filter technique has a problem that a new bit array must be generated every time a set of items is changed. In addition, since it is judged based on a continuous write request, it is possible to make a wrong judgment. In this paper, we propose a method using a counting filter for accurate hot data verification. The proposed method examines consecutive write requests. It also records the number of times consecutive write requests occur. The proposed method enables more accurate hot data verification.

• 사물인터넷융복합논문지
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• 제8권5호
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• pp.77-83
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• 2022

낸드 플래시 메모리는 구조적으로 쓰기 전 지우기(Erase-Before-Write) 동작이 요구된다. 이것을 해결하기 위해서는 데이터 업데이트 동작이 빈번히 발생하는 페이지(Hot data page)를 구분하여 별도에 블록에 저장함으로 해결할 수 있으며 이러한 Hot data를 분류하는 기법을 핫 데이터 판단기법이라 한다. MHF(Multi Hash Function Framework)기법은 데이터 갱신요청의 빈도를 시스템 메모리에 기록하고 그 기록된 값이 일정 기준 이상일 때 해당 데이터 갱신요청을 Hot data로 판단한다. 하지만 데이터 갱신요청에 빈도만을 단순히 카운트하는 방법으로는 정확한 Hot data로 판단에 한계가 있다. 또한 데이터 갱신요청의 지속성을 판단 기준으로 하는 기법의 경우 갱신요청 사실을 시간 간격을 기준으로 순차적으로 기록한 뒤 Hot data로 판단하는 방법이다. 이러한 지속성을 기준으로 하는 방법의 경우 그 구현과 운용이 복잡한 단점이 있으며 갱신요청에 빈도를 고려하지 않는 경우 부정확하게 판단되는 문제가 있다. 본 논문은 데이터 갱신요청에 빈도와 지속성을 함께 고려한 경량화된 핫 데이터 판단기법을 제안한다.

• 대한한의진단학회지
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• 제19권3호
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• pp.141-149
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• 2015

Objectives Recently the fuzzy logic is widely used in the decision making, identification, pattern recognition, optimization in various fields. In this study, we propose the fuzzy logic as the objective method of distinguishing hot and cold, the basis of diagnosis in Korean medicine. Methods We developed fuzzy inference system to distinguish whether the subjects had hot or cold. The cold and hot questionnaire of Korean traditional university textbook, the pulse rate and the DITI value of face used in the system. These three kinds of information were defined as 'fuzzy sets,' and 54 fuzzy rules were established on the basis of clinical practitioners' knowledge. The fuzzy inference was performed by using the Mamdani's method. To evaluate the usefulness of the fuzzy inference system, 200 cases of data measured in the Woosuk university hospital of oriental medicine were used to compare the determining hot, normal, cold results obtained from the experts and from the proposed system. Results As a result, 100 cases of "cold", 54 cases of "normal", and 34 cases of "hot" were matched between the experts and the proposed system. This fuzzy system showed the conformity degree of 94%(${\kappa}=0.853$). Conclusions In this study, we could express the process of distinguishing hot-cold using the fuzzy logic for objectification and quantification of hot-cold identification. This is the first study that introduce a fuzzy logic for distinguish pattern identification. The degree of the heat characteristic of the patients inferred by this system could provide a more objective basis for diagnosing the hot-cold of patients.

• 사물인터넷융복합논문지
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• 제8권5호
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• pp.33-39
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• 2022

모바일 컴퓨팅 분야에서 사용되는 저장장치는 저전력, 경량화, 내구성 등을 갖추어야 하며 사용자에 의해 생성되는 대용량 데이터를 효과적으로 저장 및 관리할 수 있어야 한다. 낸드 플래시 메모리는 모바일 컴퓨팅 분야에서 저장장치로 주로 사용되고 있다. 낸드 플래시 메모리는 구조적 특징 때문에 데이터 갱신요청 시 제자리 덮어쓰기가 불가능하여 데이터 갱신요청이 자주 발생하는 요청과 그렇지 않은 요청을 정확히 구분하여 각 블록에 저장 및 관리함으로써 해결할 수 있다. 이러한 데이터 갱신요청에 분류기법을 핫 데이터 식별 기법이라고 하며 현재 다양한 연구가 진행되었다. 본 논문은 더 정확한 핫 데이터 검증을 위해 카운팅 필터를 사용하여 데이터 갱신요청 발생을 연속적으로 기록하고 또한 특정 시간 동안 요청된 갱신요청이 얼마나 자주 발생하는지를 고려하여 핫 데이터를 검증한다.

• 한국컴퓨터정보학회논문지
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• 제20권12호
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• pp.1-8
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• 2015

Wear leveling techniques have been studied to prolong the lifetime of NAND flash memory. Most of studies have used Program/Erase(P/E) cycles as wear index for wear leveling. Unfortunately, P/E cycles could not predict the real lifetime of NAND flash blocks. Therefore, these algorithms have the limited performance from prolonging the lifetime when applied to the SSD. In order to apply the real lifetime, wear leveling algorithms, which use raw Bit Error Rate(rBER) as wear index, have been studied in recent years. In this paper, we propose CrEWL(Cold data identification using raw Bit error rate in Wear Leveling), which uses rBER as wear index to apply to the real lifetime. The proposed wear leveling reduces an overhead of garbage collections by using HBSQ(Hot Block Sequence Queue) which identifies hot data. In order to reduce overhead of wear leveling, CrEWL does not perform wear leveling until rBER of the some blocks reaches a threshold value. We evaluate CrEWL in comparison with the previous studies under the traces having the different Hot/Cold rate, and the experimental results show that our wear leveling technique can reduce the overhead up to 41% and prolong the lifetime up to 72% compared with previous wear leveling techniques.

• Smart Structures and Systems
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• 제4권6호
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• pp.795-807
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• 2008

A challenging problem in structural damage detection based on vibration data is the requirement of a large number of sensors and the numerical difficulty in obtaining reasonably accurate results when the system is large. To address this issue, the substructure identification approach may be used. Due to practical limitations, the response data are not available at all degrees of freedom of the structure and the external excitations may not be measured (or available). In this paper, an adaptive damage tracking technique, referred to as the sequential nonlinear least-square estimation with unknown inputs and unknown outputs (SNLSE-UI-UO) and the sub-structure approach are used to identify damages at critical locations (hot spots) of the complex structure. In our approach, only a limited number of response data are needed and the external excitations may not be measured, thus significantly reducing the number of sensors required and the corresponding computational efforts. The accuracy of the proposed approach is illustrated using a long-span truss with finite-element formulation and an 8-story nonlinear base-isolated building. Simulation results demonstrate that the proposed approach is capable of tracking the local structural damages without the global information of the entire structure, and it is suitable for local structural health monitoring.

• 대한한방부인과학회지
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• 제34권4호
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• pp.78-96
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• 2021

Objectives: It is a statistical study to examine the data of CaPSPI (Diagnostic System for Climacteric and Postmenopausal Syndrome Pattern Identification), developed for diagnosis of menopause disorders and to record the status of treatment of it. Methods: From November 1, 2020 to June 19, 2021, 36 cases of data of 33 respondents of the CaPSPI were analyzed. For the use of the basic data of the clinical menopausal disorder, we investigated frequency of menopausal symptoms and the difference between them depending on the period of menopause, and the presentation of usage prescriptions. And the diagnostic results for three kinds' diagnosis [for examination (D1), for treatment (D2), by doctors (D3)] were compared. The diagnostic consistency of D1 and D3 and the statistical significance between DT and disease elements (證素) was investigated. Results: 1. Hot flush was the highest in the symptom survey of the menopause that the subjects complained of, followed by insomnia. There was no significant difference in symptom expression according to menopausal period. 2. The diagnostic consistency of D1 and D2 showed significant diagnostic consistency only in liver depression, and the diagnostic consistency of D1 and D3 showed significant consistency in liver depression and Dual Deficiency of Heart and Spleen. 3. D3' diagnosis and disease elements had statistical significance for cases of P<0.1 was found to be related to the theory of oriental medicine. Conclusions: It is needed to continue to accumulate diagnosis and treatment results through CaPSPI in the future to strengthen the basis for patten identification and treatment of menopause disorders.

• 한국의류산업학회지
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• 제21권2호
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• pp.151-162
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• 2019

This study identifies influential factors in regards to the purchase of celebrity fashion hot items and compares these factors in the age groups of teens and twenties. This study surveyed male and female consumers aged 10-20 years old for empirical analysis in July 2018. The study surveyed 322 consumers selected through online convenience sampling. Data were analyzed using SPSS for Windows 19.0, descriptive statistics, reliability analysis, ${\chi}^2$ analysis, regression analysis, ANOVA analysis, Duncan test, and t-test. The results were as follows. First, 87.6% of consumer have purchased celebrity fashion hot items more than once. In particular, female consumers in their 20s with a high fashion product expenditure tend to purchase more celebrity fashion hot items. Clothes and shoes were purchased more by 10-year-old males, shoes for males in their 20s, accessories for 10-year-old females female, and bags and accessories for female in their 20s. Second, there were no significant differences for those aged 10-20 years old in purchase satisfaction for celebrity fashion hot items according to age, gender, income, and fashion product expenditure. Consumers' awareness on corporate marketing intention to celebrity fashion hot items was higher among women in their 20s than men in their teens and twenties; in addition, the expenditure on fashion products also increased. Third, factors affecting the purchase of celebrity fashion hot items among teens and twenties were different according to age and gender. A higher need for identification for teenage male resulted in: lower media dependency, higher product involvement, fashion conformity, fashion innovativeness for 20s males, higher product involvement for 10s and 20s females, increased intention to purchase tended. This study provides consumer information and fashion item information that can be utilized in advertisement and promotion strategies for fashion companies that seek to perform celebrity marketing strategies that target consumers aged 10-20 years old.

• 원예과학기술지
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• 제30권2호
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• pp.192-200
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• 2012

형질전환 작물 개발시, 위해성 평가에 영향을 미치게 될 요인들을 파악하고, 이에 대한 과학적 근거의 마련을 위한 실험 자료 생산계획의 확립과 실험을 진행하는 것이 매우 중요하다. 또한 유전자변형작물을 개발한 후 정부의 승인을 위한 과학적이고 신뢰할 만한 자료를 축적하기 위해서는 오랜 기간과 많은 자본이 투입된다. 이에 따라, 본 연구에서는 CMV 저항성 유전자변형 고추에 대한 평가분석 연구를 통해 유전자변형작물의 환경위해성 평가를 수행하는데 있어 도입유전자 확인을 위한 평가서 작성을 위해 요구되는 서던 분석을 위한 탐침 포화, 도입유전자의 발현 해석을 위한 RT-PCR, ELISA 실험에 관한 사례를 제시하고자 하였다. 서던 분석을 위해 삽입 유전자 전체 서열의 확인이 가능한 10개의 부분적으로 겹치는 탐침을 제작하였다. 서던 분석 결과, 고추에 도입된 외래유전자가 단일사본으로 존재하여, 게놈전체에서 도입된 위치 이외에 상동성을 갖는 다른 조각 부위가 없음을 확인하였으며, 도입유전자 전체의 안정성을 확실히 입증할 수 있었다. 그와 더불어, 역전사 중합효소 연쇄반응 및 효소면역법 실험을 통하여, CMV 저항성 고추의 잎, 과실 등과 같은 주요 기관에서의 삽입 유전자에 대한 안정적인 발현을 확인 할 수 있었다.