• The Journal of Information Systems
• /
• v.18 no.4
• /
• pp.41-57
• /
• 2009

Although financial information is a great influence upon determining of the group which use them, detection of management fraud and earning manipulation is a difficult task using normal audit procedures and corporate credit evaluation processes, due to the shortage of knowledge concerning the characteristics of management fraud, and the limitation of time and cost. These limitations suggest the need of systemic process for !he effective risk of earning manipulation for credit evaluators, external auditors, financial analysts, and regulators. Moot researches on management fraud have examined how various characteristics of the company's management features affect the occurrence of corporate fraud. This study examines financial characteristics of companies engaged in fraudulent financial reporting and suggests a model and system for detecting GAAP violations to improve reliability of accounting information and transparency of their management. Since the detection of management fraud has limited proven theory, this study used the detecting method of outlier(upper, and lower bound) financial ratio, as a real-field application. The strength of outlier detecting method is its use of easiness and understandability. In the suggested model, 14 variables of the 7 useful variable categories among the 76 financial ratio variables are examined through the distribution analysis as possible indicators of fraudulent financial statements accounts. The developed model from these variables show a 80.82% of hit ratio for the holdout sample. This model was developed as a financial outlier detecting system for a financial institution. External auditors, financial analysts, regulators, and other users of financial statements might use this model to pre-screen potential earnings manipulators in the credit evaluation system. Especially, this model will be helpful for the loan evaluators of financial institutes to decide more objective and effective credit ratings and to improve the quality of financial statements.

• Journal of Korean Academy of Nursing
• /
• v.28 no.2
• /
• pp.256-269
• /
• 1998

The purpose of this study was to evaluate the usefulness of variables which were known to be related to blood pressure for discriminating between hypertensive and normotensive groups. Variables were obesity, serum lipids, life style-related variables such as smoking, alcohol, exercise, and stress, and demographic variables such as age, economical status, and education. The data were collected from 400 male clients who visited one university hospital located in Incheon, Republic of Korea, from May 1996 to December 1996 for a regular physical examination. Variables which showed significance for discriminating systolic blood pressure in this study were age, serum lipids, education, HDL, exercise, total cholesterol, body fat percent, alcohol, stress, and smoking(in order of significance). By using the combination of these variables, the possibility of proper prediction for a high-systolic pressure group was 2%, predicting a normal-systolic pressure group was 70.3%, and total Hit Ratio was 70%. Variables which showed significance for discriminating diastolic blood pressure were exercise, triglyceride, alcohol, smoking, economical status, age, and BMI (in order of significance). By using the combination of these variables, the possibility of proper prediction for a high-diastolic pressure group was 71.2%, predicting a normal-diastolic pressure group was 71.3%, and total Hit Ratio was 71.3%. Multiple regression analysis was performed to examine the association of systolic blood pressure with life style-related variables after adjustment for obesity, serum lipids, and demographic variables. First, the effect of demographic variable alone on the systolic blood pressure was statistically significant (p=.000) and adjusted $R^2$was 0.09. Adding the variable obesity on demographic variables resulted in raising adjusted $R^2$to 0.11 (p=.000) : therefore, the contribution rate of obesity on the systolic blood pressure was 2.0%. On the next step, adding the variable serum lipids on the obesity and demographic variables resulted in raising adjusted R2 to 0.12(P=.000) : therefore, the contribution rate of serum lipid on the systolic pressure was 1.0%. Finally, adding life style-related variables on all other variables resulted in raising the adjusted $R^2$to 0.18(p=.000) ; therefore, the contribution rate of life style-related variables on the systolic blood pressure after adjustment for obesity, serum lipids, and demographic variables was 6.0%. Multiple regression analysis was also performed to examine the association of diastolic blood pressure with life style-related variables after adjustment for obesity, serum lipids, and demographic variables. First, the effect of demographic variable alone on the diastolic blood pressure was statistically significant (p=.01) and adjusted $R^2$was 0.03. Adding the variable obesity on demographic variables resulted in raising adjusted $R^2$to 0.06 (p=.000) ; therefore, the contribution rate of obesity on the diastolic blood pressure was 3.0%. On the next step, adding the variable serum lipids on the obesity and demographic variables resulted in raising the adjusted $R^2$ to 0.09(p=.000) ; therefore, the contribution rate of serum lipid on the diastolic pressure was 3.0%. Finally, adding life style-related variables on all other variables resulted in raising the adjusted $R^2$ to 0.12 (p=.000) : therefore, the contribution rate of life style-related variables on the systolic blood pressure after adjustment for obesity, serum lipids, and demographic variables was 3.0%.

• Journal of Korean Society of Transportation
• /
• v.28 no.6
• /
• pp.147-158
• /
• 2010

Studies on the distribution of traffic demands have been proceeding by providing traffic information for reducing greenhouse gases and reinforcing the road's competitiveness in the transport section, however, since it is preferentially required the extensive studies on the driver's behavior changing routes and its influence factors, this study has been developed a discriminant model for changing routes considering driving conditions including traffic conditions of roads and driver's preferences for information media. It is divided into three groups depending on driving conditions in group classification with the CART analysis, which is statistically meaningful. And, elements of the driving conditions and the preferred media affecting the change of paths are classified into statistical meaningful groups through the CHAID analysis, and the major factors affecting the change of paths are examined. Finally, the extent that driving conditions and preferred media affect a route change is examined through a discriminant analysis, and it is developed a discriminant model equation to predict a route change. As a result of building the discriminant model equation, it is shown that driving conditions affect a route change much more, the entire discriminant hit ratio is derived as 64.2%, and this discriminant equation shows high discriminant ability more than a certain degree.

• Journal of KIISE:Information Networking
• /
• v.28 no.4
• /
• pp.463-476
• /
• 2001

To support the mobility, mobile computers are generally equipped with lower capability than desktop PCs or workstations in terms of the size of a display, the processing power of CPU and so on. This may give a rise to limitation in mobile computers of supporting multimedia services such as World Wide Web which users would otherwise fully enjoy in desktop PCs. Approaches to reducing the limitations are distillating original multimedia data or converting them to text. Conventional proxy servers for mobile computer simply send distillated image files with the fixed size regardless of the display size of a target mobile computer. Since the cached data is kept separately for each user, they cannot be shared among users with the same display configuration and thus the proxy server could be overloaded. In this paper, we first classify various mobile computers based on their display capability in terms of display sizes and colors. We propose an enhanced proxy server called Class-based proxy that provides a mobile computer with distillated image files in proportion to its class display capacity. The proposed proxy server allows a mobile computer user to have a homepage view similar to that in PC or Workstation. Mobile computers with the same class share the cached image files, which are distillated appropriately for that class. This helps the proxy server to get higher cache hit ratio with improved efficiency and scalability.

• Journal of KIISE:Information Networking
• /
• v.37 no.3
• /
• pp.167-174
• /
• 2010

Recently the distributed topology control algorithm for constructing the Recrystallization Topology in the unstructured peer-to-peer network was proposed. In this paper, we prove that such a hierarchical topology is a scale-free power-law network. We present a model of a construction process of the distributed protocol, and analyze it based on a mean-field approximation and the continuum theory, so that we show that the constructed Recrystallization Topology is a scale-free network. In the proposed model, all nodes are born with some initial attractiveness and the system incorporates the rewiring of some links at every time step. Some old links are removed with the anti-preferential probability, and some new links are added with preferential probability. In other words, according to the distributed algorithm, each node makes connections to the more-preferential nodes having higher hit-ratio than other nodes, while it disconnects the anti-preferential nodes having lesser hit-ratio. This gives a realistic description of the local processes forming the recrystallization topology in unstructured peer-to-peer network. We calculate analytically the degree distribution. The analytic result indicates that the constructed network is a scale-free network, of which the scaling exponent is 3.

• Radiation Oncology Journal
• /
• v.11 no.1
• /
• pp.17-27
• /
• 1993

To investigate the relationship between radiosensitivity and postirradiation recovery in human cancer cells, a study was performed using human cancer cell lines-A549, CaSki, SNU-C5 and PCI-13. For the study of radiosensitivity, single doses of 2, 4, 6, 8, 10, 12, and 14 Gy were given and for postirradiation recovery, two fractions of 4 Gy were separated with a time interval of 0, 0.5, 1, 1.5, 2, 2.5, 3, 4, 5, or 6 hours. Surviving fraction was estimated using colony forming ability. Surviving fractions at 2 Gy (SF2) were 0.496 (0.570-0.412) for A549, 0.496 (0.660-0.332) for CaSki, 0.386 (0.576-0.216) for SNU-C5, and 0.185 (0.247-0.123) for PCI-13. By statistical analysis the SF2 of PCI-13 was lower significantly than those of others (p<0.05). This difference was also observed at 4, 6 and 8 Gy dose levels. At 6 and 8 Gy the surviving fractions of SNU-C5 were also lower significantly than A549 and CaSki (p<0.05). By the analysis with linear quadratic model, the values of ${\alpha}$ for A549, CaSki, SNU-C5 and PCI-13 were 0.3016, 0.3212, 0.4327 and 0.8423, respectively, and those of ${\beta}$ were 0.02429, 0.02009, 0.03349 and 0.00059, respectively. So, the value of ${\alpha}$ showed increasing tendency with decreasing SF2. By the multitarget single hit model the values of Do for A549, CaSki, SUN-C5 and PCI-13 were 1.97, 1.97, 1.46 and 0.81, respectively, and those of n were 1.53, 1.50, 1.56 and 2.28, respectively. So, the value of Do decreased with decreasing SF2. Post-irradiation recovery reached plateau at around 2 hours. Recovery ratio at plateau phase ranged from 1.2 to 4.2; the value were 1.2 for PCI-13, 3.2 for CaSki, 3.3 for SNU-C5, and 4.2 for A549. Recovery rate well correlated with SF2, and increased with increasing Do and decreasing ${\alpha}$. According to above results, the intrinsic radiosensitivity was quite different among the tested cell lines; PCI-13 was the most sensitive and A549 and CaSki was similar. This difference of radiosensitivity is thought to be partly due to the difference in amount of postirradiation recovery. By linear quadratic model the difference of ${\alpha}$ values was very high, and by multitarget single hit model the difference of Do value was significantly high among four cell lines.

• The KIPS Transactions:PartA
• /
• v.13A no.7 s.104
• /
• pp.615-622
• /
• 2006

Caching in a Wireless Internet Proxy Server Cluster Environment has an effect that minimizes the time on the request and response of Internet traffic and Web user As a way to increase the hit ratio of cache, we can use a hash function to make the same request URLs to be assigned to the same cache server. The disadvantage of the hashing scheme is that client requests cannot be well-distributed to all cache servers so that the performance of the whole system can depend on only a few busy servers. In this paper, we propose an improved load balancing scheme using hashing and Round Robin scheme that distributes client requests evenly to cache servers. In the existing hashing scheme, if a hashing value for a request URL is calculated, the server number is statically fixed at compile time while in the proposed scheme it is dynamically fixed at run time using round robin method. We implemented the proposed scheme in a Wireless Internet Proxy Server Cluster Environment and performed experiments using 16 PCs. Experimental results show the even distribution of client requests and the 52% to 112% performance improvement compared to the existing hashing method.

• The KIPS Transactions:PartB
• /
• v.11B no.5
• /
• pp.563-572
• /
• 2004

Sentence ion is a simplification of a sentence preserving its communicative function. It accomplishes sentence revision and concept ion simultaneously. Sentence revision is a method that resolves the discrepancy between human's thoughts and its expressed semantic in sentences. Concept ion is an expression of general ideas acquired from the common elements of concepts. Sentence ion selects the main constituents of given sentences and describes the upper concepts of them with detecting their semantic information. This enables sen fence revision and concept ion simultaneously. In this paper, a syntactic parser LGPI+ and an ontology OfN are utilized for sentence ion. Sentence abstracter SABOT makes use of LGPI+ and OfN. SABOT processes the result of parsing and selects the candidate words for sentence ion. This paper computes the sentence recall of the main sentences and the topic hit ratio of the selected sentences with the text understanding system using sentence ion. The sources are 58 paragraphs in 23 stories. As a result of it, the sentence recall is about .54 ～ 72% and the topic hit ratio is about 76 ～ 86%. This paper verified that sentence ion enables sentence revision that can select the topic sentences of a given text efficiently and concept ion that can improve the depth of text understanding.

• Journal of KIISE:Computer Systems and Theory
• /
• v.33 no.5
• /
• pp.306-315
• /
• 2006

In general, the hit ratio of the first level cache is one of the most important factors in determining the performance of computer systems. Prefetching from lower level memory structure is one of the most useful techniques for improving the hit ratio of the first level cache. In this paper, we propose a prefetch on continuous same page access (CSPA) scheme which improves the prefetch efficiency of the instruction cache and reduces prefetch cost at the same time. The proposed CSPA scheme traces the page addresses of executed instructions to count how many times the same memory page is accessed continuously. To increase the prefetch efficiency, the CSPA scheme initiates prefetch only if the number of accesses to the same page exceeds the threshold value. Generally, the size of a L1 cache block is smaller than that of a L2 cache block. Therefore, one L2 cache block contains a number of L1 cache blocks. To reduce the number of unnecessary accesses to the L2 cache due to prefetch, the CSPA scheme enables prefetch only when the missed L1 block and the prefetch L1 block are in the same L2 cache block, leading to reduced prefetch cost. According to our simulations, the proposed prefetching scheme improves the performance by up to 6.7%.

• Journal of Internet Computing and Services
• /
• v.16 no.5
• /
• pp.19-27
• /
• 2015

Due to the advantages of fast read/write operation and low power consumption, SSD(Solid State Drive) is now widely adopted as storage device of smart phone, laptop computer, server, etc. However, the shortcomings of SSD such as limited number of write operations and asymmetric read/write operation lead to the problem of shortened life span of SSD. Therefore, the block replacement policy of SSD used as cache for HDD is very important. The existing solutions for improving the lifespan of SSD including the LARC scheme typically employ the LRU algorithm to manage the SSD blocks, which may increase the miss rate in SSD due to the replacement of frequently used block instead of rarely used block. In this paper we propose a novel block replacement scheme which considers the block reuse interval to effectively handle various data read/write patterns. The proposed scheme replaces the block in SSD based on the recency decided by reuse interval and age along with hit ratio. Computer simulation using workload trace files reveals that the proposed scheme consistently improves the performance and lifespan of SSD by increasing the hit ratio and decreasing the number of write operations compared to the existing schemes including LARC.