• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.22 no.6
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• pp.57-62
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• 2022

Recently, fast storage media such as phage-change memory (PCM) emerge, and memory management policies for slow disk storage need to be revisited. In this paper, we propose a new page replacement policy that makes use of PCM as a swap device of virtual memory systems. The proposed policy aims at reducing write traffic to the swap device as well as reducing the number of page faults pursued by traditional page replacement policies. This is because a write operation in PCM is slow and PCM has limited write endurances. Specifically, the proposed policy focuses on the reduction of page faults when the memory load of the system is high, but it aims at reducing write traffic to storage when free memory space is sufficient. Simulation experiments with various memory reference traces show that the proposed policy reduces write traffic to PCM without performance degradations.

• Analytical Science and Technology
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• v.21 no.6
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• pp.502-509
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• 2008

An ID LC/MS (isotope dilution liquid chromatography/mass spectrometry) was used as a primary method for the quantitative analysis of cholesterol in human serum. The separation of cholesterol was carried out by Thermo ODS hypersil $C^{18}$ column. The mobile phase was 100% methanol, and flow rate was $0.3m{\ell}/min$. Cholesterol and cholesterol-$3,4-13C_2$ were monitored at m/z 369.4 and 371.3, which correspond to $[M-H_2O+H]^+$ respectively. In order to verify the measurement method, NIST SRM 909b was analyzed. The results agreed well with certified values within uncertainty. The four kinds of serum certified reference material were prepared and certified. The repeatabilities of measurement were ranged from 0.1 to 0.8% (RSD), which were relatively good. The reproducibility between independent measurement run was below 0.24% (RSD). The expanded uncertainty was about 1.43% within the 95% confidence interval.

• 중국학논총
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• no.53
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• pp.1-16
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• 2017

The grammatical meaning of "了", a marker of aspects in Mandarin has been described differently among researchers, three of which are to express the end, a certain phase of event and the start of an event or a state. This paper consists of four parts. Set out below is a summary of main points of each part. The first chapter elaborates on the results of previous related studies, points out the purpose and meaning of the current study. Chapter two introduces marked "了" including concepts of the meaning and "Done", "complete whole", "realization" Corresponds to the case study. And explains syntactic and semantic features of the "了", highlights the look "of the了" problems of syntax and semantics, "了2" made three domains Limit 3 Including of the knowledge. This chapter holds that its grammartical meaning can be described as follows an event has taken place or a state has formed prior to a certain reference time, and that the grammartical meanings mentioned above can be considered sub - grammartical meanings of "了",which result from different prominence of the phases of an event. Chapter three explains tag component of the "了1", "了2". It discusses limited constraints, first place for "了" syntactic meaning, "The End" and "extension" of the opposition for "了" is looming around the root system, "了" and "着" sentence structure and semantic and syntactic forms. Chapter four discusses bounded features of the 了. It mainly focuses on "了"of bounded / unbounded function. It analyses the functions of components and explains a bounded function of "了1" and a bounded function of "了2". Chapter five is the conclusion. It consolidates and summarises the previous contents of the paper and points out the conclusion.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.10a
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• pp.570-573
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• 2022

This paper presents the identification of void diameters for a cast-resin transformer using an artificial neural network (ANN) model. A PD signal was measured by the Rogowski coil sensor which has the planar and thin structures fabricated on a printed circuit board (PCB), and the PD electrode system was fabricated to simulate a PD defect by a void. In addition, void samples with different diameters were fabricated by injecting air in a cylindrical aluminum frame using a syringe during the epoxy curing process. To identify the diameter of void defects, PD characteristics such as the discharge magnitude, pulse count, and phase angle were extracted and back propagation algorithm (BPA) was designed using virtual instrument (VI) based on the Labview program. From the experimental results, the BPA algorithm proposed in this paper has over 90% accurate rate to identify the diameter of void defects and is expected to use reference data of maintenance and replacement of insulation for cast-resin transformers in the on-site PD measurement.

• Journal of the Korea Society of Computer and Information
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• v.28 no.12
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• pp.231-238
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• 2023

For boost PFC (Power Factor Correction) converters, various control methods are being studied to achieve unity power factor and low THD (Total Harmonic Distortion) of AC input current. Among them, average current mode control, which controls the average value of the inductor current to follow the current reference, is the most widely used. However, nowadays, as advanced digital control becomes possible with the development of digital processors, predictive control of boost PFC converters is receiving attention. Predictive control is classified into predictive current mode control, which generates duty in advance using a predictive algorithm, and model predictive current control, which performs switching operations by selecting a cost function based on a model. Therefore, this paper simply explains the average current mode control, predictive current mode control, and model predictive current control of the boost PFC converter. In addition, current control under entire load and disturbance conditions is compared and analyzed through simulation.

• Korean Journal of Radiology
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• v.1 no.1
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• pp.38-42
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• 2000

Objective: The purpose of this study was to determine the utility of preoperative CT in predicting early recurrence of hepatocellular carcinoma after partial hepatic resection. Materials and Methods: Preoperative three-phase helical CT scans in 53 patients with hepatocellular carcinoma were retrospectively reviewed by two radiologists. In 27 patients (group I), HCC had recurred within six months, while 26 (group II) had remained disease free for at least two years. In each group, preoperative CT findings were evaluated in each group for the tumor size and number, the presence or absence of capsule, distinctness of tumor margin, perinodular extension, and the presence or absence of portal vein thrombosis. Results: In group I, a tumor capsule of tumor was seen in five of 27 patients (19%), and in group II, in 16 of 26 (62%) (p = .001). The tumor margin was distinct in eight patients (30%) in group I and in 20 (77%) in group II (p = .001). Multiple tumors, perinodular extension, and portal vein thrombosis were more frequently seen in group I but the differences were not statistically significant (p > .05). Tumor size was similar in each group (p > .05). Conclusion: Preoperative CT findings that may help predict the early recurrence of hepatocellular carcinoma after surgical resection are an absence of capsule of tumors and an indistinct margin. Reference to these findings during preoperative CT can guide clinicians in their choice of treatment.

• Journal of the Korea institute for structural maintenance and inspection
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• v.28 no.2
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• pp.9-16
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• 2024

In this paper, we aimed to convert the fire curve in volume units to a fire curve per unit area for application in the Fire Dynamic Simulator (FDS) surface heat release rate method. The fire curve was expressed dimensionlessly considering the total combustion characteristic time, and improvements were made to represent the appropriate ratios for the growth , steady, and decay phases concerning the fire intensity. Additionally, a correction function for combustion characteristic time varying with mass increase was derived. Also to control the growth time values according to the increase in mass, a function to correct the growth phase ratio was derived. Consequently, utilizing existing data, a formula was established to determine the reference mass for combustion materials and predict the fire curve based on mass increase.

• Journal of Intelligence and Information Systems
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• v.26 no.1
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• pp.97-117
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• 2020

Product evaluation criteria is an indicator describing attributes or values of products, which enable users or manufacturers measure and understand the products. When companies analyze their products or compare them with competitors, appropriate criteria must be selected for objective evaluation. The criteria should show the features of products that consumers considered when they purchased, used and evaluated the products. However, current evaluation criteria do not reflect different consumers' opinion from product to product. Previous studies tried to used online reviews from e-commerce sites that reflect consumer opinions to extract the features and topics of products and use them as evaluation criteria. However, there is still a limit that they produce irrelevant criteria to products due to extracted or improper words are not refined. To overcome this limitation, this research suggests LDA-k-NN model which extracts possible criteria words from online reviews by using LDA and refines them with k-nearest neighbor. Proposed approach starts with preparation phase, which is constructed with 6 steps. At first, it collects review data from e-commerce websites. Most e-commerce websites classify their selling items by high-level, middle-level, and low-level categories. Review data for preparation phase are gathered from each middle-level category and collapsed later, which is to present single high-level category. Next, nouns, adjectives, adverbs, and verbs are extracted from reviews by getting part of speech information using morpheme analysis module. After preprocessing, words per each topic from review are shown with LDA and only nouns in topic words are chosen as potential words for criteria. Then, words are tagged based on possibility of criteria for each middle-level category. Next, every tagged word is vectorized by pre-trained word embedding model. Finally, k-nearest neighbor case-based approach is used to classify each word with tags. After setting up preparation phase, criteria extraction phase is conducted with low-level categories. This phase starts with crawling reviews in the corresponding low-level category. Same preprocessing as preparation phase is conducted using morpheme analysis module and LDA. Possible criteria words are extracted by getting nouns from the data and vectorized by pre-trained word embedding model. Finally, evaluation criteria are extracted by refining possible criteria words using k-nearest neighbor approach and reference proportion of each word in the words set. To evaluate the performance of the proposed model, an experiment was conducted with review on '11st', one of the biggest e-commerce companies in Korea. Review data were from 'Electronics/Digital' section, one of high-level categories in 11st. For performance evaluation of suggested model, three other models were used for comparing with the suggested model; actual criteria of 11st, a model that extracts nouns by morpheme analysis module and refines them according to word frequency, and a model that extracts nouns from LDA topics and refines them by word frequency. The performance evaluation was set to predict evaluation criteria of 10 low-level categories with the suggested model and 3 models above. Criteria words extracted from each model were combined into a single words set and it was used for survey questionnaires. In the survey, respondents chose every item they consider as appropriate criteria for each category. Each model got its score when chosen words were extracted from that model. The suggested model had higher scores than other models in 8 out of 10 low-level categories. By conducting paired t-tests on scores of each model, we confirmed that the suggested model shows better performance in 26 tests out of 30. In addition, the suggested model was the best model in terms of accuracy. This research proposes evaluation criteria extracting method that combines topic extraction using LDA and refinement with k-nearest neighbor approach. This method overcomes the limits of previous dictionary-based models and frequency-based refinement models. This study can contribute to improve review analysis for deriving business insights in e-commerce market.

• The Korean Journal of Nuclear Medicine Technology
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• v.13 no.3
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• pp.159-164
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• 2009

Purpose: The automatic notification system for alarm values on blood tests conducted by this hospital is designed to immediately inform the attending physician of the result of a blood test, to help the relevant patient to promptly receive proper treatment, and furthermore, to reduce the likelihood of a fatal influence to the patient. From 2004, the clinical pathology department of this hospital has been operating an automatic notification system for blood tests, in relation to the items of WBC, Hb, Plt, PB cell morphology, Malaria, PT, aPTT, BT, fibrinogen, Ca, K, Na, Cl, Mg, Glucose, Ketone, Digoxin, PKU, Homocystinuria, 17-OHP, Neonatal TSH, and Galactosemia. Recently, the blood test room of the nuclear medicine department has been operating an automatic notification system for the alarm values of a blood test, in relation to three items of TSH, FT4, and 17-${\alpha}$-OH-PGR, and the details of its operation will be described here. Materials and Methods: The subjects were newborn babies that were receiving TSH, FT4, and $17{\alpha}$-OH-PGR prescriptions from February $19^{th}$ to May $11^{st}$, 2009, and who met with the following criteria: N2340 Thyroid-Stimulating Hormone: >$10{\mu}IU/mL$ (Reference value: 0.4~5.0). N2360 Free-Thyroxine: <$0.8{\mu}g/dL$ (Reference value: 0.8~1.9), N2444 $17{\alpha}$-OH-Progesterone: >$30\;{\mu}g/mL$ (Reference value: Male (0.6~3.42), Female follicular phase (0.19~1.8). The automatic notification system was operated by entering test items, relevant treatment departments, and standard values for reporting alarm values into the OCS program, and then transmitting results that met with the input conditions to the PDAs of the prescription and the attending physician by SMS. Results: Reporting an alarm value of the nuclear medicine blood test, which can have a fatal influence on the lives of patients, will help cure patients, improve the quality of the test, and furthermore, will increase the patient's satisfaction with the prescription and treatment of the test.

• The Journal of Korean Society for Radiation Therapy
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• v.33
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• pp.25-33
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• 2021

Purpose : The purpose of this study is to evaluate the accuracy and usefulness of the Trigger mode for the Respiratory Gated Radiation Therapy (RGRT) Materials and methods : A QUASAR respiratory phantom that inserted a 3 mm fiducial marker (a gold marker) was used to estimate the accuracy of the Trigger mode. And the 20 bpm was used as reference respiration rate in this study. The marker that placed at the center of the phantom was contoured, and the lower threshold of a gating window was fixed at 2.0 mm using an OBI with Truebeam STx^TM. The upper threshold was measured every 0.5 mm from 1.0 mm to 3.0 mm. The respiration rates were changed every 10 bpm from 10 bpm to 60 bpm. We repeatedly measured five times to check the error rate of the trigger mode in the same condition. Result : The differences of a distance from a peak phase to upper threshold, 1.0 to 3.0 mm at a 20 bpm as a reference for 3 days in a row were 0.68±0.05 mm, 0.91±0.03 mm, 1.23±0.03 mm, 1.42±0.04 mm, and 1.66±0.06 mm, respectively. Measurement result of changes in respiratory rate compared to baseline respiratory rate in maximum absolute difference. The coefficient of determination (R2) to estimate the correlation between the respiration velocity and variation of absolute difference was on average 0.838, 0.887, 0.770, 0.850, and 0.906. The p-values of all the variables were below 0.05. Conclusion : Using Trigger mode during respiratory gated radiation therapy (RGRT), accuracy and usefulness of trigger mode at reference breathing rate were confirmed. However, inaccuracies depending on the rate of breathing it could be uncertain in case of respiration rate is faster than 20 bpm as a standard respiration rate compared to slower than 20 bpm. Consequently, when conducting a RGRT using the trigger mode, real time monitoring is required with well educated respiration.