Hee Eun Kim a, Han Sung Son b, Hyun Gook Kang c,* a Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 34141 b Department of Gaming, Joongbu University, 201 Daehak-ro, Chubu-myeon, Geumsan-gun, Chungnam, 312-702, c Department of Aerospace and Nuclear Engineering Rensselaer Polytechnic Institute, Troy, NY 12180, USA

The digitalization of the instrumentation and control (I&C) systems in nuclear power plants has increased the threat from cyber-attack. This paper addresses cyber-attack vulnerability from potential attacks on non-safety I&C systems that result in a hazardous plant status. In safety-critical applications such as nuclear power plants, safety systems are separated and isolated from non-safety systems by design. Cyber-attacks on the non-safety systems can however escalate into plant safety threats by inducing wrong operator actions. We focus here on the operator actions that lead to the unavailability of the safety system and cause the failure of accident mitigation. In this study, the effect of safety system unavailability on plant safety is carefully modeled by using n conventional fault tree (FT) analyses, and human actions are analyzed based on emergency operating procedures. Based on the results of the FT analyses in combination with human action analyses, we suggest a novel method to systematically develop cyber-attack propagation scenarios, where a cyber-attack is linked to its consequences. As a case study, the feed-and-bleed operation is analyzed with the developed FT, producing multiple scenarios that lead to core damage. The results of this study are expected to be useful in establishing preventive measures

Software failure probability quantification is an important aspect of digital system reliability assessment. Several quantification methods currently available in the software reliability field have characteristics unsuitable for application to safety-critical software. In this paper, a software test framework in consideration of input trajectory is developed, and a software failure probability quantification method is also suggested. The test input cases consist of the states and present inputs, where input trajectory is represented by the state. To obtain the input domain, which represents realistic plant behavior, digital system characteristics and plant dynamics are considered. This allows software failure probability to be estimated by using the result of each representative test case, thus reducing testing efforts. The proposed framework was applied to a nuclear power plant reactor protection system as an example to show its effectiveness. The method provides a practical and relatively simple way to test software and estimate software failure probability.

The Engineered Safety Feature-Component Control System (ESF-CCS), which uses a network communication system for the transmission of safety-critical information from group controllers (GCs) to loop controllers (LCs), was recently developed. However, the ESF-CCS has not been applied to nuclear power plants (NPPs) because the network communication failure risk in the ESF-CCS has yet to be fully quantified. Therefore, this study was performed to identify the potential hazardous states for network communication between GCs and LCs and to develop quantification schemes for various network failure causes. To estimate the risk effects of network communication failures in the ESF-CCS, a fault-tree model of an ESF-CCS signal failure in the containment spray actuation signal condition was developed for the case study. Based on a specified range of periodic inspection periods for network modules and the baseline probability of software failure, a sensitivity study was conducted to analyze the risk effect of network failure between GCs and LCs on ESF-CCS signal failure. This study is expected to provide insight into the development of a fault-tree model for network failures in digital I&C systems and the quantification of the risk effects of network failures for safety-critical information transmission in NPPs.

The purpose of this study was to investigate the effect of aquatic lower limb muscle strengthening program on lower limb muscle function and gait in Korean hemiplegia stroke patient. Subjects were 20 hemiplegia stroke patients aged from 40 to 60 and they participated in the aquatic lower limb muscle strengthening program during 12 weeks. The exercise intensity was 12–16 (50–85% VO2max) RPE. Gait analysis, lower limb function mobility, balance ability, lower limb muscle were measured before and after the exercise. Collected data were analyzed by paired t‐test and independent t‐test with using SPSS window 18.0 version. After aquatic lower limb muscle strengthening program, gait distance was increased (P<0.001) and gait course angle was decreased (P<0.05). Lower limb function mobility (P<0.05), balance ability (P<0.001), lower limb muscle (P<0.001) were also increased after the program. Interestingly, after aquatic lower limb muscle strengthening program, left hemiplegia stroke patients presented higher increase in lower limb muscle strength than right hemiplegia stroke patients (P<0.05). In conclusion, aquatic lower limb muscle strengthening program improves gait and lower limb function in Korean hemiplegia stroke patients. Therefore, aquatic lower limb muscle strengthening program may be considered as proper rehabilitation exercise program for stroke patients.

With the improvement of digital technologies, digital protection system (DPS) has more multiple sophisticated fault-tolerant techniques (FTTs), in order to increase fault detection and to help the system safely perform the required functions in spite of the possible presence of faults. Fault detection coverage is vital factor of FTT in reliability. However, the fault detection coverage is insufficient to reflect the effects of various FTTs in reliability model. To reflect characteristics of FTTs in the reliability model, integrated fault coverage is introduced. The integrated fault coverage considers the process of FTT from detection to fail-safe generation process. A model has been developed to estimate the unavailability of repairable component of DPS using the integrated fault coverage. The new developed model can quantify unavailability according to a diversity of conditions. Sensitivity studies are performed to ascertain important variables which affect the integrated fault coverage and unavailability. (C) 2013 Elsevier B.V. All rights reserved.

The demand to complement the elderly body shape with comfortable clothing has greatly increased with the growing elderly population and their improved social-economic level. However, apparel industries have not provided significant production and sale strategies that reflect and consider elderly body shape characteristics. This study investigated the demand and complaints of current silver wear. This study was conducted on 100 elderly people 65 and over. The questionnaires were composed of Korean Activities of Daily Living (K-ADL) that reflect the general characteristics of the respondents related to clothing (clothing requirements and demands) and free comments on each question. Subsequently, we found that the most uncomfortable clothing parts were 'sleeve length' and 'crotch' in women and 'neck circumference' and 'pocket' in men when wearing shirts and pants respectively. Respondents felt that the button and zipper knob sizes were too small with the buttons too numerous. The results suggest that we should consider body shape changes caused by aging in order to develop elderly clothing patterns to improve the level of ADL. We anticipate apparel industries for the elderly to expand due to the rapid increase in the elderly population.

This study examines the wearing comfort of elderly women through a physiological analysis based on rectal temperature and biochemical analysis with salivary melatonin and cortisol. This study was conducted on 7 elderly women aged 65 or over. Two kinds of clothing ensemble (control and prototype) were used as experimental clothing. The control clothing was a general clothing ensemble and the prototype clothing lowered clothing pressure by adding an extra gap. The experimental schedule included daily living activities with randomly assigned experimental clothing. Rectal temperature was constantly measured every 5 minutes during the experiment and saliva samples for melatonin and cortisol were collected twice per day before and after sleep. The rectal temperature was lower for the prototype than the control throughout the experiment, and its circadian rhythm was prompt and clear in prototype. In addition, melatonin was secreted more but cortisol was secreted less when the subjects wore the prototype clothing. With these results, we assumed that regular circadian rhythm and low level of stress might be caused by wearing prototype clothing that lowered clothing pressure. The results demonstrate the necessity to develop clothing that considers body changes in elderly women.

Many safety-critical applications including nuclear power plants are equipped with k-out-of-n or specific-voting-logic redundant safety signal generation systems for ensuring both safety and economy. In order to determine the configuration of these safety signal generation systems and to analyze the risk from these systems, common cause failures must be considered carefully. The study aims to develop a quantification method of the system unavailability and the spurious operation probability in consideration of the CCF. Analytic equations are developed and three popular configurations for the RPS (2-out-of-3, 2-out-of-4, and selective 2-out-of-4 voting) are investigated as examples. The quantitative results of this study show that the CCF dominates the system unavailability and the SOP for the small channel failure probability. (C) 2012 Elsevier Ltd. All rights reserved.

This study compares and analyzes cosmetics purchasing behavior according to the advertising and publicity implemented in women's monthly magazines as well as determines effective marketing strategies for the cosmetics industry. First, cosmetics advertising and publicity in women's monthly magazines can be classified into conventional advertising, advertorials, beauty news based on press releases, and beauty articles written by editors. In addition, consumer purchasing behavior has been examined in terms of use of information, purchasing intention, and purchasing experience. A study was conducted on women in their 20's to 40's in Seoul and Gyeonggi-do with 289 questionnaires used in the final analysis. Data were analyzed by common factor analysis, randomized block design, Bonferroni adjusted t-test, and multiple linear regression using SPSS 12.0/Windows. The results of the study can be summarized as follows. First, there was a difference in purchasing behavior according to types of cosmetics advertising and publicity in women's monthly magazines. Second, cosmetics shopping orientations were classified into six factors (the pursuit of impulsive purchasing and trends, well-known brands, convenience, low prices, efficacy and brand loyalty). There were significant effects of shopping orientation on cosmetics purchasing behavior according to the type of advertisement and publicity in women's monthly magazines.

This study examined the clothing wearing comfort of elderly women by electroencephalogram (EEG) and electrocardiogram (ECG) analyses. This study utilized 7 elderly individuals aged 65 or more. Two kinds of clothing ensemble (control and prototype) were used as experimental clothing. The control consisted of a general clothing ensemble and the prototype consisted of clothing that added an extra gap. Subjects wore the control or prototype from 9:00 to 21:30 and EEG and ECG signals were measured in the last 30 minutes. The EEG analysis showed that relative band power of a and ${\alpha}$/high ${\beta}$ were higher when they wore the prototype rather than the control. The ECG analysis showed that absolute band power of HF was higher; however, absolute band power of LF and LF/HF was lower when they wore the prototype rather than the control. Subjects felt less stressful and more comfortable when they wore the prototype. The results demonstrate the necessity to develop clothing in consideration of the body changes in elderly women. It is significant that the assessment of wearing comfort was aided by the use of EEG and ECG analysis in the field of clothing and textiles.

The Kruppel like factor 5 (KLF5) is a zinc‐finger transcription factor that plays important roles in regulating all aspects of cellular signaling involved in cell proliferation and oncogenesis. In the present study, KLF5 interacts with sterol regulatory element‐binding protein‐1 (SREBP‐1) in regulating the expression of lipogenic protein, fatty acid synthase (FASN), which plays important roles in androgen‐dependent prostate cancer cells. Genes involved in lipid metabolism, including FASN, are reported to be up‐regulated by androgens in prostate cancer cells through a coordinated cascade controlled by the activation of SREBP‐1. The promoter and intron 1 region of FASN gene contains multiple GC‐boxes that might show response to KLF5. Deletion and mutation analyses indicated that KLF5 binds to the FASN gene and strongly induces its activity. Furthermore, KLF5 protein is able to bind to SREBP‐1 and enhance the SREBP‐1 regulated activation of FASN. Transfection of KLF5 into prostate cancer cells enhanced FASN promoter activity, and conversely, silencing of KLF5 by siRNA down‐regulated FASN expression. The multiple GC motifs are scattered throughout the upstream sequence and first intron of FASN gene whereas these are scarce in the promoters of other lipogenic and cholesterogenic genes such as acetyl‐CoA carboxylase, ATP‐citrate lyase, LDL receptor, HMG‐CoA synthase and HMG‐CoA reductase, which makes FASN gene very unique among them. Taken together, FASN gene could be activated by the synergistic action of KLF5 and SREBP‐1 which is increased by androgen treatment.

Abstract The present paper is aimed at determining whether the dressing behavior for temperature regulation in cold is under the influences of circadian control. The half-naked subjects were instructed to dress in the garments they felt comfortable when the room temperature began to decrease from 30°C to 15°C in 1 h. To determine the effects of brain temperature fall on the dressing behavior, we used face cooling with cool air for 30 min before the room temperature began to decrease. We also studied the effects of wearing a hat on dressing behavior. Rectal temperature, tympanic temperature, skin temperature at seven sites, and thermal sensation were recorded. Major findings are summarized as follows: 1) the subjects dressed faster with thicker clothing in the morning than in the evening; 2) the subjects with face cooling dressed faster with thicker clothing than the subjects without face cooling; 3) the subjects without a hat dressed more rapidly with thicker, heavier clothing. These results were discussed in terms of load error between actual and set-point values in the core temperature.