• Journal of the Korea Society of Computer and Information
• /
• v.22 no.2
• /
• pp.1-7
• /
• 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.

• Journal of the Korea Society of Computer and Information
• /
• v.24 no.6
• /
• pp.1-9
• /
• 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.

• Journal of Internet of Things and Convergence
• /
• v.8 no.5
• /
• pp.77-83
• /
• 2022

Nand flash memory requires an Erase-Before-Write operation structurally. In order to solve this problem, it can be solved by classifying a page (hot data page) where data update operation occurs frequently and storing it in a separate block. The MHF (Multi Hash Function Framework) technique records the frequency of data update requests in the system memory, and when the recorded value exceeds a certain standard, the data update request is judged as hot data. However, the method of simply counting only the frequency of the data update request has a limit in judging it as accurate hot data. In addition, in the case of a technique that determines the persistence of a data update request, the fact of the update request is recorded sequentially based on a time interval and then judged as hot data. In the case of such a persistence-based method, its implementation and operation are complicated, and there is a problem of inaccurate judgment if frequency is not considered in the update request. This paper proposes a lightweight hot data determination technique that considers both frequency and persistence in data update requests.

• The Journal of the Society of Korean Medicine Diagnostics
• /
• v.19 no.3
• /
• pp.141-149
• /
• 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.

• Journal of Internet of Things and Convergence
• /
• v.8 no.5
• /
• pp.33-39
• /
• 2022

A storage device used in the mobile computing field should have low power, light weight, durability, etc., and should be able to effectively store and manage large-capacity data generated by users. NAND flash memory is mainly used as a storage device in the field of mobile computing. Due to the structural characteristics of NAND flash memory, it is impossible to overwrite in place when a data update request is made, so it can be solved by accurately separating requests that frequently request data update and requests that do not, and storing and managing them in each block. The classification method for such a data update request is called a hot data identification method, and various studies have been conducted at present. This paper continuously records the occurrence of data update requests using a counting filter for more accurate hot data validation, and also verifies hot data by considering how often the requested update requests occur during a specific time.

• Journal of the Korea Society of Computer and Information
• /
• v.20 no.12
• /
• pp.1-8
• /
• 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
• /
• v.4 no.6
• /
• pp.795-807
• /
• 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.

• The Journal of Korean Obstetrics and Gynecology
• /
• v.34 no.4
• /
• pp.78-96
• /
• 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.

• Fashion & Textile Research Journal
• /
• v.21 no.2
• /
• pp.151-162
• /
• 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.

• Horticultural Science & Technology
• /
• v.30 no.2
• /
• pp.192-200
• /
• 2012

For the development of genetically modified plants, it is important to verify various factors which potentially affect the risk assessment as well as to establish an experimental program to produce scientific and reliable data. However, it is a time and cost consuming process to develop GM plants as well as to prepare scientific and convincible data for government's approval. Therefore, using the transgenic hot pepper tolerant to a new CMV pathotype, we attempted to suggest few methodological procedures, such as probe saturation for southern blot analysis and RT-PCR and ELISA for expression analysis, for identification and stability evaluation of inserted gene in genetically modified plant which are required for submission for approval. Ten partially overlapped probes covering full length of inserted gene were produced. We could identify that the inserted gene was stacked as a single copy as well as no partial element existed. Also, we could identify the stability of the inserted gene stacked in hot pepper using probe saturation. In the expression analysis with RT-PCR and ELISA, we also could provide the stable expression of transcript and proteins in leaves and placenta and pericarp of fruits of the CMV-resistant hot pepper.