• Journal of KIISE:Computer Systems and Theory
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• v.33 no.3
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• pp.178-192
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• 2006

The buffer overflow attack is the single most dominant and lethal form of security exploits as evidenced by recent worm outbreaks such as Code Red and SQL Stammer. In this paper, we propose microarchitectural techniques that can detect and recover from such malicious code attacks. The idea is that the buffer overflow attacks usually exhibit abnormal behaviors in the system. This kind of unusual signs can be easily detected by checking the safety of memory references at runtime, avoiding the potential data or control corruptions made by such attacks. Both the hardware cost and the performance penalty of enforcing the safety guards are negligible. In addition, we propose a more aggressive technique called corruption recovery buffer (CRB), which can further increase the level of security. Combined with the safety guards, the CRB can be used to save suspicious writes made by an attack and can restore the original architecture state before the attack. By performing detailed execution-driven simulations on the programs selected from SPEC CPU2000 benchmark, we evaluate the effectiveness of the proposed microarchitectural techniques. Experimental data shows that enforcing a single safety guard can reduce the number of system failures substantially by protecting the stack against return address corruptions made by the attacks. Furthermore, a small 1KB CRB can nullify additional data corruptions made by stack smashing attacks with only less than 2% performance penalty.

• Journal of KIISE:Information Networking
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• v.31 no.6
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• pp.582-594
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• 2004

In school PC labs or other educational purpose PC labs with a few dozens of PCs, computers are configured in a distributed architecture so that they are set up, maintained and upgraded separately. As an alternative to the distributed architecture, we can consider a thin-client computing environment. In a thin-client computing environment, client side devices provide mainly I/O functions with user friendly GUI and multimedia processing support whereas remote servers called terminal server provide computing power. In order to support many clients in the environment, a cluster of terminal servers can be configured. In this architecture, it is difficult due to the characteristics of terminal session persistence and different pattern of computing usage of users so that the utilization of terminal server resources becomes low. To overcome this disadvantage, we propose an adaptive terminal cluster where terminal servers ,ire partitioned into groups and a terminal server in a light-loaded group can be dynamically reassigned to a heavy-loaded group at run time. The proposed adaptive scheme is compared with a generic terminal service cluster and a group based non-adaptive terminal server cluster. Experimental results show the effectiveness of the proposed scheme.

• The Journal of the Korea Contents Association
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• v.11 no.4
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• pp.378-388
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• 2011

The purpose of this study is to clarify the impact on cohesiveness and organizational performance of the servant leadership of the security manager. The subjects of study selected final 287 persons by using the systematic random sampling for security companies in Seoul in 2009. However, the number of cases used in the final analysis is 256 persons. Reliability of the questionnaire used in this study showed that the value of Cronbach's ${\alpha}$ was above 0.796. The collected data used the methods such as factor analysis, reliability analysis, and multiple regression analysis etc. by using SPSSWIN 17.0. The conclusions are as follows. First, servant leadership has a positive impact on cohesiveness. Second, one of the factors of servant leadership, trust, has a positive impact on organizational performance. Third, individual, social cohesiveness and group cohesiveness among the factors of cohesiveness have a positive impact on organizational performance. Fourth, with the results of path analysis, servant leadership has direct impact on organizational effectiveness and indirect impact through cohesiveness. In other words, a servant leadership among the leaderships that a security worker is conscious of administrator affects cohesiveness and organizational performance in management to promote the management of the organization.

• The Journal of Korean Medicine
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• v.27 no.4
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• pp.198-208
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• 2006

Background : Ginseng has traditionally been used in oriental countries to recover vital energy from Qi deficiency, and has shown various biomedical effects in the scientific literature. Recent reports suggest that ginseng could regulate blood pressure (BP), but much controversy still remains. Therefore, we intended to assess the anti-hypertensive effect of several ginseng types frequently used in clinics. We also investigated the anti-hypertensive effect on Koreans and Chinese, and by the body type according to Sasang Constitution Medicine (SCM). Methods : The study subjects were recruited from mildly hypertensive patients who exhibited pre-hypertension(120/80 to 139/89 mmHg) and stage I hypertension (140/90 to 159/99 mmHg) in Korea and China. After assigning the subjects into a Korean, a Chinese, a red, and an American ginseng group by randomization, we prescribed ginseng at a dose of 4.5 g per day for 4 weeks. To assess the anti-hypertensive effect, we compared the mean of systolic and diastolic BP between before and after ginseng medication using a 24-hour ambulatory blood pressure monitor (24 hr ABPM. We also monitored adverse effect and laboratory findings to secure the subjects' safety. In addition, all of the subjects in Korea consulted a specialist of Sasang Constitution Medicine to identify their constitutional type. Results : There were 64 subjects treated with Korean ginseng, 58 treated with Chinese ginseng, 33 treated with red ginseng, and 64 treated with American ginseng. Korean, Chinese, and American ginseng all reduced subjects' BP; Korean and Chinese ginseng showed more effect. The secondary analysis on the subjects' nationality revealed that all of the ginseng types showed more significant anti-hypertensive effect in Chinese patients than in Koreans. The third analysis on the constitutional type of SCM showed there was no significant difference in the effectiveness and the safety of ginseng among the constitutional types. Conclusions : We suggest ginseng, especially Panax ginseng without any steaming-drying process, could be useful for mild hypertension. Further, ginseng is safe regardless of subjects' constitutional type or type of ginseng within a dosage of 4.5g per day.

• The Journal of Korean Medicine
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• v.31 no.4
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• pp.101-114
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• 2010

Background: Currently, evidence-based medicine is widely propagated as a reference for proper clinical practice. As a result, there is an increasing need for more clinical trials based on Oriental diagnostic methods to evaluate the efficacy of Oriental medicine, including acupuncture and herbal medicine. The purpose of this study was to confirm which symptoms are adequate indicators of effects of Ojeock-san for lower back pain and develop a questionnaire to evaluate its effects. Methods: We interviewed 102 Oriental medical doctors working in Seoul with a preformed questionnaire which included questions about symptoms of lower back pain and indicators for Ojeock-san. We sampled respondents who answered that they trust the effectiveness of Ojeock-san in telephone survey carried out using multistage stratified random sampling technique from March to April, 2009. We categorized the respondents into two groups, differentiating them by gender, career, workplace, and trust level of Ojeock-san effect. Results: About half of the respondents selected 13 questions as the adequate indicators of Ojeock-san for low back pain. There were no differences in the top 11 selected indicators in total selection and top 3 ranking selection. The comparison of frequency of top 13 questions in total selections between the two groups showed no difference. Conclusions: There were 13 symptoms which were considered adequate indicators of effects of Ojeock-san for lower back pain found by many Oriental medical doctors. This questionnaire can be utilized as a diagnostic adjunctive tool, tested for validity and reliability of questionnaires through further studies.

• The Journal of the Korea Contents Association
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• v.14 no.1
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• pp.223-237
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• 2014

The purpose of this study is to understand the perceptions of public officials in improving primary health care service for local communities by applying Q methodology that draw upon schematic model in subjectivity study. A survey was carried out among public officials at Gangneung Community Health Center, South Korea, to classify the 49 selected Q-statements into a normal distribution using a 11 point scale. The collected data was analyzed using QUANL program, and principal component factor analysis using varimax rotation was used to identify public officials' perceptions of improving quality of health care for local communities as a meaningful service provider. Type I can be categorized by a strong concern for the service acceptance, Type II can be categorized by advocating for service usability, Type III can be categorized by the pursuit of service specialization, Type IV can be categorized by roles for service accessibility, and Type V can be categorized by the suggestions for operation and management. The results provide information used to further improve quality of community health care service with the aim to promote the effectiveness of health care delivery and to increase health service utilization.

• The Journal of the Korea Contents Association
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• v.14 no.5
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• pp.107-116
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• 2014

The purpose of this study is to verify the applicability of concept mapping in the process of planning social welfare program based on community network. Concept mapping is a kind of decision-making method that structuralized complex ideas and presented visually. Already, concept mapping is widely utilized in counseling, nursing and public health area to plan and evaluation their program and service. For recent, effectiveness of concept mapping has been reported. Concept mapping is a effective decision-making method that they recognize outcome gap between service provider and client, reach the outcome's consensus in counseling and nursing, medical area. In this study, we conceptualized 3rd year outcomes of Community Impact Project that was supported from Busan Chest using concept mapping. This CI project intervenes children and youth who lives in Buk-gu, Busan. Concept mapping has six stages-preparation, collecting ideas, structuring statements, representing statement, interpreting the results of the analysis, applying the results. We followed these steps. The participants were working at social welfare organizations, total 11 persons. We obtained 60 statements and analyzed using multidimensional scaling. we collected 5 clusters, cluster 1 'awareness and attitude change of children and youth', cluster 2 'social system change of children and youth', cluster 3 'friendly community formation', cluster 4 'community people change', cluster 5 'service provider change'. As a result, among total 5 clusters formed, 'awareness and attitude change of children and youth' came to the strongest outcomes. When concept mapping was applied to the program planning, the consensus of the opinion came easily in the decision-making process, and the participants were empowered. In addition, clear conceptualization on each element of the program planning was made.

• The Journal of the Korea Contents Association
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• v.14 no.5
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• pp.458-467
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• 2014

Pain is one of the most common and painful symptoms that cancer patients suffer from. Pain seriously affects 30-50% of the patients at the early cancer diagnosis stage or who receive active anticancer treatments, 60-70% of the patients with progressive cancer, and 80-90% of the patients at the late stage of cancer. However, there is no systematic and easy pain control program for the cancer patients. In this study, an algorithm is proposed to provide quick pain relief service upon the occurrence of sudden pain, for the purpose of controlling the sudden pain that cancer operation survivors experience. In developing the algorithm, questionnaires, evaluation forms and National Comprehensive Cancer Network (NCCN) guideline were considered, and a trial service was provided to a group of 20 cancer patients for a month to evaluate the designed algorithm. The results of the trial service were examined by expert medical workers to evaluate the proposed algorithm, and a 90% compatibility decision was derived, which verified the effectiveness of the proposed algorithm. In the case of incompatibility decision, the management of the pain diary did not have compatible results. Therefore, the further study will additionally address the customized pain diary algorithm.

• Journal of the Korea Organic Resources Recycling Association
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• v.23 no.4
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• pp.74-85
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• 2015

Recently, the number of anaerobic digestion facility for livestock manure is on the rise in Korea. All of the livestock manure anaerobic digestion facilities in operation use pig manure slurry as a substrate for anaerobic digestion. Generally, pig manure slurry is composed of 97% water and 3% solids. The particulate matter, such as corn in the form of particles that is undigested by pig is contained in the pig manure slurry. Particulate matter is a factor reducing the effectiveness of biogas production in the anaerobic digestion process. In this study, mechanical grinding treatment was applied to analyze the effect of methane production from pig manure slurry by reducing the particle size of the slurry. On the other hand, the effect of the solid concentration levels on methane production and methane content of the biogas was analyzed. The fine particle concentration in the pig manure slurry was increased by the mechanical grinding treatment. And methane production and methane content of the biogas were higher in grinded pig manure slurry than untreated raw slurry.

• Archives of Plastic Surgery
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• v.36 no.3
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• pp.336-340
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• 2009

Purpose: The wound of a patient who has chronic venous insufficiency is easy to recur. Also they develop a complication even after the conservative therapy or skin graft. We have to diagnose the venous stasis ulcer correctly and remove the cause to improve the effectiveness of treatment. We operated endoscopic perforating vein ligation and splitt thickness skin graft on a patient with venous stasis ulceration on right leg. Methods: A 26 year old male patient who had a scalding burn on his right leg in July 2005 checked into our hospital in March 2008. Even though he got three operations - the split thickness skin graft - at different clinics, the wound did not heal. The size of the wound was 12 by $8cm^2$ and granulation with edema and fibrosis had been formed. We kept observation on many collateral vessels and perforating vein through venogram and doppler sonography and firmly get to know that the wound came with chronic venous insufficiency. After a debridement and an application of VAC$^{(R)}$ for two weeks, the condition of granulation got better. So we proceeded with the operation using subfascial endoscopic perforating surgery and split thickness skin graft. Results: Through the venogram after the operation, we found out that the collateral vessels had been reduced compared to the previous condition and the widened perforating vein disappeared. During a follow up of 6 months, the patient did not develop recurrent stasis ulcer and postoperative complications. Conclusion: Subfascial endoscopic perforator ligation is relatively simple technique with a low complication rate and recurrence rate. Split thickness skin graft with subfascial endoscopic perforator surgery can be valuable method for treating severe venous stasis ulcers.