• International Journal of Naval Architecture and Ocean Engineering
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• v.13 no.1
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• pp.24-34
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• 2021

This paper predicts the speed-power-rpm relationship in regular head waves using various indirect methods: load variation, direct powering, resistance and thrust identity, torque and revolution, thrust and revolution, and Taylor expansion methods. The subject ship is KVLCC2. The wave conditions are the regular head waves of λ/LPP = 0.6 and 1.0 with three wave steepness ratios at three ship speeds of 13.5, 14.5 and 15.5 knots (design speed). In the case of λ/LPP = 0.6 at design speed, two more wave steepness ratios have been taken into consideration. The indirect methods have been evaluated through comparing the speed-power-rpm relationships with those obtained from the resistance and self-propulsion tests in calm water and in waves. The load variation method has been applied to predict propulsive performances in waves, and to derive overload factors (ITTC, 2018). The overload factors have been applied to obtain propulsive efficiency and propeller revolution. The thrust and revolution method (ITTC, 2014) has been modified.

• Proceedings of the Korean Society of Food Hygiene and Safety Conference
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• 2002.05a
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• pp.138-138
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• 2002

Oxidative stress has been associated with a number of diseases in human. Among the sources that can generate oxidative stress, it has been reported that iron can generate reactive oxygen species (ROS)with thiol. In iron overload state, increased thiol levels in plasma appeared to be associated with human mortality. In this study we examined whether iron could interact with thiols in plasma, generating ROS. In human plasma, unlike with Fe(III), Fe(II) increased lucigenin-enhanced chemiluminescence in concentration-dependent manner, and this was inhibited by SOD. Boiling of plasma did not affect chemiluminescence induced by Fe(II). Hovever, thiol depletion in plasma by pretreatment with N-ethylmaleimide (NEM)decreased Fe(II)-induced chemiluminescence significantly, suggesting that Fe(II) generated superoxide anion by the nonenzymatic reaction with plasma thiol. Consistent with this findings, albumin, the major thiol contributor in plasma, also generated ROS with Fe(II) and this generation was inhibited by pretreatment with NEM. Treatment with Fe(II) to plasma resulted un significant reduction of oxygen radical absorbance capacity (ORAC) value, suggest that total antioxidant capacity could diminished in iron overload state. In conclusion, In iron overload state, plasma may be affected by oxidative stress mediated by nonenzymatic reaction of Fe (II)with plasma thiol.

• Management & Information Systems Review
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• v.36 no.1
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• pp.81-94
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• 2017

In the age of information overload such as Internet of Things(IoT), big data, and cloud computing, Data and informations are collected to processed regardless of the individual's will. The purpose of this paper presents a model related to personal information overlord, information privacy risk, information privacy concern (collection, control, awareness) and personal information privacy protective response. The results of this study is summarized as follows. First, personal information overload significantly affects information privacy risk. Second, personal information overload significantly affects information privacy concern(collection, control, awareness) Third, information privacy risk significantly affects collection and awareness among information privacy concern, but control does not significantly affects. This results shows that users are cognitively aware the information risk through collection and awareness of information. Users can not control information by self, control of information does not affects. Last, information privacy concern(collection and awareness significantly affect information privacy protective response, but information privacy concern (control) does not affect. Personal information users are concerned about information infringement due to excessive personal information, ability to protect private information became strong.

• The Transactions of the Korea Information Processing Society
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• v.3 no.7
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• pp.1727-1738
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• 1996

This paper proposes a extended service filtering technique to solve overload control problems inService Con-trol Poin(SCP) due to Televoting (VOT) services with heavy traffic characteristics. Also, this paper compares this new technique with existing IN overload control lechniques, and calculate steady state call blocking probabilities in In under overload conditions. The proposed technique considers SCP overload and IN CS-1services such as VOT service that need to use the specialized resources of IP. This technique uses first an activating step which SCP sends service filtering request to SSP and IP for the start of service filtering. Then, in the filtering step SSP sendas filtering results to SCP periodically or each N-calls.Also,when filtering time-out timer expired or call counter value exceeded maximum number of calls,SSP stops service filtering,and sends ser-vice filteing response to SCP in the deactivating step. The application of this techique to VOT service defined in IN CS-1 service is investigated and analyzed by using an analytical VOT service model.In order to apply this technique to VOT service, this paper also discusses VOT service and the corresponding N architecture including Service Switching Point(SSP),SCP and IP. Then this paper also constructs an analytical VOT service model,and calculates SCP and SSP/IP(circuit)call blocking probablities.With the application of this new technique,this paper shows good performance enhancements in SCP call blocking probability.

• Journal of Korea Multimedia Society
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• v.15 no.8
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• pp.1038-1047
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• 2012

The SIP(Session Initation Protocol) is an application layer protocol that is used to establish, release, and change the call session of the IP telephony. In the SIP signalling networks, when the number of the UA(User Agent) requested the call session increase, the number of messages to be processed by SIP proxy server increase. It often will be caused the overload of the SIP proxy server. In this paper, we proposed the overload control method with a normal queue and a delay queue in the SIP proxy server. When it is estimated the overload of the server by the excess of the high threshold in the normal queue, new INVITE messages will be put into the delay queue to reduce the load of the server. It results in some delay of the call session from the INVITE message. Subsequently when the number of messages in the normal queue is reduced below the low threshold, the INVITE messages in the delay queue is processed. The simulation results showed that the number of the retransmission messages by our proposed method was 45% less than the one by the method with single queue. The results also showed that the average call success rate by the proposed method was 2% higher than the one by the method with single queue.

• Korean Journal of Occupational Health Nursing
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• v.8 no.1
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• pp.56-67
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• 1999

This study was designed to identify the relationships of role-conflict and role-overload, coping strategies, and stress response of clerical workers. The subjects were 115 clerical workers from two company. The instruments were the role-conflict and role-overload scale developed by Lee(1989), coping scale developed by Latack(1986), and the stress response scale developed by Chang(1993). Analysis of data was done by descriptive statistics, Cronbach's $\alpha$, Pearson correlation coefficietnt, ANOVA. The results of this study were summarized as follows ; 1. The average score for the level of stress response was $83.6({\pm}9.1)$. The high risk stress group was 86.1% of the clerical workers, the latent stress group members was 13.9%, and healthy group was 0%. The overall stress level was very high. 2. Considering the coping strategies by sociodemographic factors, the use of control coping strategies showed significant differences by work-time. The use of symptom management coping strategies showed significant differences by sex, age, married status, year of career, pay, and type of work. The organizational coping strategies showed significant differences by year of education and type of work. 3. The clerical workers who had worked below 44 hours per week complained significantly lower stress response(F=4.942, p<.05). 4. Above 65% of all respondents answered that they needed all of organizational level coping strategies. 5. The role-confilct positively related to escape and organizational level coping strategies(r=.562, r=.495, p<.05). The role-overload didn't related to individual level coping strategies, but positively related to organizational level coping strategies(r=.320, p<.05). 6. The control coping strategies and the escape coping strategies positively related to symptom management, organizational level coping strategies(r=.409, r=.324, r=.316, r=.339, p<.05). 7. The relationship between role-related stress and stress response revealed positive correlation(r=.482, r=.431, p<.05), and the relationship between stress response and control, symptom management coping strategies revealed negative cor-relation(r=-.3204, r=-.3146, p<.05). In conclusion, this study revealed that relationship of role related stress, coping strategies, stress response was statistically significant. The result of this study support that coping strategies vary across situation of stress. Based on survey results, future studies should consider coping strategies in specific stress situation and concept of symptom management coping strategy. Also organizational or training interventions could be developed and initiate to help to increase the use of adaptive coping strategies in light of individual and situational differences.

• The Transactions of the Korea Information Processing Society
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• v.4 no.7
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• pp.1804-1820
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• 1997

In this paper, an efficient call control procedure is presented for next generation wireless ATM networks and its performance is mathematically analyzed using the open queueing network. This procedure is based on a new scheme called as the cell clustering. When we use the cell clustering scheme, at the time that a mobile connection is admitted to the network, a virtual cell is constructed by choosing a group of neighboring base stations to which the call may probabilistically hand over and by assigning to the call a collection of virtual paths between the base stations. Within a microcell/picocell environment, it is seen that the cell clustering can support effectively a very high rate of handovers, provides very high system capacity, and guarantees a high degree of frequency reuse over the same geographical region without requiring the intervention of the network call control processor each time a handover occurs. But since mobiles, once admitted, are free to roam within the virtual cell, overload condition occurs in which the number of calls to be handled by one base station to exceed that cell site's capacity of radio channel. When an overload condition happens, the quality of service is abruptly degraded. We refer to this as the overload state and in order to quantify the degree of degradation we define two metrics, the probability of overload and the normalized average time spent in the overload state. By using the open network queueing model, we derive closed form expressions for the maximum number of calls that can be admitted into the virtual cell such that the two defined metrics are used as the acceptance criteria for call admission control.

• The Journal of the Korea Contents Association
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• v.15 no.1
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• pp.366-378
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• 2015

The purpose of this study conducted in the United States was to identify the level of role stressors among professions at centers for independent living and to investigate the relationship between role stressors and burnout at the target population. A total of 218 professions completed a web-based and hard copy survey. The participants reported a mean (standard deviation) score of 22.48 (5.80) for the role conflict dimension, 22.20 (4.30) for the role ambiguity dimension, and 9.14 (2.55) for the role overload. Demographic assessment of the differences on the mean score of the three role stressors revealed significant associations with that age, job title, highest level of education, years of human service experience and working hours per week for role conflict/role ambiguity, and experience in human service for role overload. The role conflict, ambiguity, and overload stressors were significant predictors of emotional exhaustion and depersonalization explaining 26% and 14% of the variance, respectively. None of the stressors significant predicted personal accomplishment. The results indicate that role conflict, ambiguity, and overload are important predictors of burnout among professions at centers for independent living.

• The Korean Journal of Blood Transfusion
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• v.29 no.3
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• pp.273-281
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• 2018

Background: Ferritin is used to detect iron overload in patients with chronic red blood cell transfusions. Although ferritin reflects the amount of iron storage in the body, it may increase nonspecifically in inflammation and infection. This study analyzed the cause of increased ferritin and the association with a red blood cell (RBC) transfusion. Methods: The medical records of patients who visited the authors' hospital from January to December 2017 and underwent a ferritin test were reviewed retrospectively. Hyperferritinemia was defined as a ferritin level more than 1,000 ng/mL. The causes of hyperferritinemia were investigated by examining the laboratory findings and medical records. Results: The results revealed 417 cases of hyperferritinemia in 238 patients during the period. The most common diseases were hematologic malignancies from 125 cases (30.0%) in 31 patients and infectious diseases were the second most common. Iron overload was suspected in 119 cases in 33 patients, and 12 patients (76 cases) were transfused with more than 8 units of RBC for 1 year before the test. Conclusion: In hyperferritinemia, the rate of iron overload is high considering the underlying diseases and chronic RBC transfusion. To determine iron storage status accurately, it will be helpful to measure the C-reactive protein (CRP) and iron saturation in the ferritin test. Careful attention should be paid to habitual iron formulations and frequent transfusions due to the possibility of iron overload.

• Journal of Intelligence and Information Systems
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• v.19 no.1
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• pp.125-139
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• 2013

Big data refers to the data that cannot be processes with conventional contemporary data technologies. As smart devices and social network services produces vast amount of data, big data attracts much attention from researchers. There are strong demands form governments and industries for bib data as it can create new values by drawing business insights from data. Since various new technologies to process big data introduced, academic communities also show much interest to the big data domain. A notable advance related to the big data technology has been in various fields. Big data technology makes it possible to access, collect, and save individual's personal data. These technologies enable the analysis of huge amounts of data with lower cost and less time, which is impossible to achieve with traditional methods. It even detects personal information that people do not want to open. Therefore, people using information technology such as the Internet or online services have some level of privacy concerns, and such feelings can hinder continued use of information systems. For example, SNS offers various benefits, but users are sometimes highly exposed to privacy intrusions because they write too much personal information on it. Even though users post their personal information on the Internet by themselves, the data sometimes is not under control of the users. Once the private data is posed on the Internet, it can be transferred to anywhere by a few clicks, and can be abused to create fake identity. In this way, privacy intrusion happens. This study aims to investigate how perceived personal information overload in SNS affects user's risk perception and information privacy concerns. Also, it examines the relationship between the concerns and user resistance behavior. A survey approach and structural equation modeling method are employed for data collection and analysis. This study contributes meaningful insights for academic researchers and policy makers who are planning to develop guidelines for privacy protection. The study shows that information overload on the social network services can bring the significant increase of users' perceived level of privacy risks. In turn, the perceived privacy risks leads to the increased level of privacy concerns. IF privacy concerns increase, it can affect users to from a negative or resistant attitude toward system use. The resistance attitude may lead users to discontinue the use of social network services. Furthermore, information overload is mediated by perceived risks to affect privacy concerns rather than has direct influence on perceived risk. It implies that resistance to the system use can be diminished by reducing perceived risks of users. Given that users' resistant behavior become salient when they have high privacy concerns, the measures to alleviate users' privacy concerns should be conceived. This study makes academic contribution of integrating traditional information overload theory and user resistance theory to investigate perceived privacy concerns in current IS contexts. There is little big data research which examined the technology with empirical and behavioral approach, as the research topic has just emerged. It also makes practical contributions. Information overload connects to the increased level of perceived privacy risks, and discontinued use of the information system. To keep users from departing the system, organizations should develop a system in which private data is controlled and managed with ease. This study suggests that actions to lower the level of perceived risks and privacy concerns should be taken for information systems continuance.