• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.7 no.7
• /
• pp.1610-1623
• /
• 2013

In-network caching is a key component of information-centric networking (ICN) for reducing content download time, network traffic, and server workload. Data center network (DCN) is an ideal candidate for applying the ICN design principles. In this paper, we have evaluated the effectiveness of caching placement and replacement in DCN with butterfly-topology. We also suggest a new cache placement policy based on the number of routing nodes (i.e., hop counts) through which travels the content. With a probability inversely proportional to the hop counts, the caching placement policy makes each routing node to cache content chunks. Simulation results lead us to conclude (i) cache placement policy is more effective for cache performance than cache replacement, (ii) the suggested cache placement policy has better caching performance for butterfly-type DCNs than the traditional caching placement policies such as ALWASYS and FIX(P), and (iii) high cache hit ratio does not always imply low average hop counts.

• The Transactions of the Korea Information Processing Society
• /
• v.5 no.10
• /
• pp.2676-2685
• /
• 1998

In order to improve the branch prediction accuracy and to reduce the BTB miss rate, this paper proposes a two-level BTB structure that adds small-sized victim BTB to the convetional BTB. With small cost, two-level BTB can reduce the BTB miss rate as well as improve the prediction accuracy of the hybrid branch prediction strategy which combines dynamic prediction and static prediction. Through the trace-driven simulation of four bechmark programs, the performance improvement by the proposed two-level BTB structure is analysed and validated. Our proposed BTB structure can improve the BTB miss rate by 26.5% and the misprediction rate by 26.75%

• Child Health Nursing Research
• /
• v.11 no.3
• /
• pp.316-321
• /
• 2005

Purpose: This study was done to evaluate the validity of Korean Denver ll developmental screening test in screening children with developmental risk. Method: The participants in the study were 113 children referred for developmental assessment in the department of rehabilitation of D University hospital. They were examined with the BSID (Bayley Scales of Infant Development) II and Korean Denver II by one occupational therapist. The data was analyzed by $x^2$ test and discriminant analysis. Results: There was a significant relationship between the Mental Developmental Index (MDI) of the BSID II and the result of the Korean Denver II. The sensitivity and specificity of Korean Denver II were 0.87 and 0.62 when abnormal MDI was defined as lower than 85 was used as a diagnosis of developmental delay. There was a significant relationship between the Psychomotor Developmental Index (PDI) of the BSID ll and the result 0.7 Korean Denver ll. The sensitivity and specificity of Korean Denver II were 0.83 and 0.51 The over-all hit ratio was $79.6\%$. Conclusion: The result showed that the Korean Denver II was valid and has good sensitivity and moderate specificity in screening developmental delay.

• Women's Health Nursing
• /
• v.15 no.4
• /
• pp.312-319
• /
• 2009

Purpose: The purpose of this study was to determine the discriminant factors of attitude pattern toward sexual violence of college women. Methods: A cross-sectional research design with non-probability samples was conducted. A total of 292 college women participated. The instruments were Attitude Pattern toward Sexual Violence, Self-Esteem Scale, Gender Role Scale, and Attitude toward Sexuality. Dependent variable is Attitude Pattern toward Sexual Violence, which is composed of two groups; cases either harmer blame or sufferer blame. Independent variables were self-esteem, attitude toward gender role, and attitude toward sexuality. Data were analyzed by SPSS WIN program and descriptive analysis, $x^2$-test, and discriminant analysis. Results: To assess the adequacy of classification, the overall hit ratio was 68.5%, and the significant predictor variable was attitude toward sexuality. Conclusion: Replication of the study needs to be considered to further enrich the specific knowledge base regarding attitude toward sexual violence among college women.

• Journal of the Korean Society for Industrial and Applied Mathematics
• /
• v.10 no.1
• /
• pp.95-105
• /
• 2006

The speed of hard disk which is based on mechanical operation is more slow than processor. The growth of processor speed is rapid by semiconductor technology, but the growth of disk speed which is based on mechanical operation is not enough. Buffer cache in main memory and disk cache in disk controller have been used in computer system to solve the speed gap between processor and I/O subsystem. In this paper, an efficient buffer cache and disk cache management scheme was proposed to restrict duplicated disk block between buffer cache and disk cache. The performance of the proposed algorithm was evaluated by simulation.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.14 no.3
• /
• pp.1065-1085
• /
• 2020

With rapid growth of content demands, device-to-device (D2D) content sharing is exploited to effectively improve the service quality of users. Considering the limited storage space and various content demands of users, caching schemes are significant. However, most of them ignore the influence of the asynchronous content reuse and the selfishness of users. In this work, the user preferences are defined by exploiting the user-oriented content popularity and the current caching situation, and further, we propose the social-aware rate, which comprehensively reflects the achievable contents download rate affected by the social ties, the caching indicators, and the user preferences. Guided by this, we model the collaborative caching problem by making a trade-off between the redundancy of caching contents and the cache hit ratio, with the goal of maximizing the sum of social-aware rate over the constraint of limited storage space. Due to its intractability, it is computationally reduced to the maximization of a monotone submodular function, subject to a matroid constraint. Subsequently, two social-aware collaborative caching algorithms are designed by leveraging the standard and continuous greedy algorithms respectively, which are proved to achieve different approximation ratios in unequal polynomial-time. We present the simulation results to illustrate the performance of our schemes.

• The Research Journal of the Costume Culture
• /
• v.13 no.1
• /
• pp.6-17
• /
• 2005

The purpose of this research is to define low body shapes of Plus-sized women at ages between 21 and 69 whose satisfied the Plus-sized judgment criteria took part in this study. This research also classifies different body types, and provides basic data for designing skirt's and slacks' prototypes according to each body type. Based on factor analysis of the measured data, seven key factors are grouped. And four different body types are classified based on the cluster analysis using factor marks. Type 1 refers to those who are tall in stature and balanced. This body type is characterized by trapezoid body shape when looked from the front, and slim the abdomen, bulge the belly and flat the buttocks when looked from the side. Type 2 refers to short and an obese body shapes, with trapezoid front and bulge abdomen and belly and flat the buttocks. Type 3 refers to those who are of medium height and long-legged body shapes, with rectangular front, protruding belly and buttocks. Type 4 refers to obese body shapes, with rectangular front, protruding abdomen and belly, flat the buttocks. 9 items are available to judge Plus-sized women's low body types and the hit ratio is 93.5%.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.15 no.8
• /
• pp.1743-1749
• /
• 2011

The multimedia data for video-on-demand(VOD) service has large, continuous and real time characteristics. The frequent disk I/O operations takes much time and decrease the system performance in multimedia services. Therefore the efficient buffer management is needed in order to reduce the disk accesses to multimedia data. This paper addresses how to increase the buffer hit ratio and the number of users in a multimedia service like VOD by increasing the utility of buffer. This paper also simulated various resource management algorithms and strategies and evaluated, compared and analyzed their performances.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2014.02a
• /
• pp.351.2-351.2
• /
• 2014

Indium tin oxide (ITO) has a lot of variations of its properties because it is basically in an amorphous state. Therefore, the differences in composition ratio of ITO can result in alteration of electrical properties. Normally, ITO is considered as transparent conductive oxide (TCO), possessing excellent properties for the optical and electrical devices. Quantitatively, TCO has transparency over 80 percent within the range of 380nm to 780nm, which is visible light although its specific resistance is less than $10-3{\Omega}/cm$. Thus, the solar cell is the best example for which ITO has perfectly matching profile. In addition, when ITO is used as transparent conductive electrode, this material essentially has to have a proper work function with contact materials. For instance, heterojunction with intrinsic thin layer (HIT) solar cell could have both front ITO and backside ITO. Because each side of ITO films has different type of contact materials, p-type amorphous silicon and n-type amorphous silicon, work function of ITO has to be modified to transport carrier with low built-in potential and Schottky barrier, and approximately requires variation from 3 eV to 5 eV. In this study, we examine the change of work function for different sputtering conditions using ultraviolet photoelectron spectroscopy (UPS). Structure of ITO films was investigated by spectroscopic ellipsometry (SE) and scanning electron microscopy (SEM). Optical transmittance of the films was evaluated by using an ultraviolet-visible (UV-Vis) spectrophotometer

• Journal of the Korean Society of Clothing and Textiles
• /
• v.28 no.3_4
• /
• pp.499-508
• /
• 2004

The purpose of this research is to define body characteristics of middle-aged men at ages between 35 and 55 whose physical changes are very prominent, by comparing the measurement data collected from this age group. This research also classifies different body types, and provides basic data for designing slacks' original forms according to each body type. Based on factor analysis of the measured data, seven key factors are grouped. And five different body types are classified based on the cluster analysis using factor marks. Type 1 refers to those who are tall and standard. This body type is characterized by trapezoid body shape when looked from the front, and slim abdomen when looked from the side. Type 2 refers to short and a little fat body shapes, with trapezoid front and protruding hip and abdomen. Type 3 refers to tall and fat body shapes, with rectangular front, protruding abdomen, and slim hip. Type 4 refers to those who are of medium height and a little obese, with rectangular front and protruding abdomen and hip. Type 5 refers to short and obese body shapes, with rectangular front, slim abdomen, and protruding hip. 12 items are available to judge middle-aged men's low body types and the hit ratio is 90%.