고령인의 키오스크 접근성 향상을 위한 인간공학 연구

학위논문(석사) -- 서울대학교대학원 : 공과대학 산업공학과, 2022.2. 박우진.In this thesis, two independent experimental studies were conducted to improve self-service kiosk (SSK) accessibility for older adults. First, in an attempt to propose an optimal on-site training tutorial design, four training methods, which were the combinations of two medium types (paper, digital) and two instruction types (goals only, goals and actions), were compared. A between-subjects experimental study that comparatively evaluated the training effects of the four methods was conducted. In the second experimental study, the impacts of potential SSK design features, that is, side partitions, a back partition, and a chair, on perceived workloads and task performance of SSK users of different age groups were evaluated. As a result of the two studies, the dissertation research proposes design implications on training materials and public SSK design. The results from the two research studies would contribute to improving accessibility for older adults as well as enhancing the user experience (UX) of public SSK.본 논문에서는 고령인의 키오스크 접근성 향상을 위한 두 가지 방안을 고려한다. 첫째, 고령인의 키오스크 사용 방법 학습 효과를 극대화하는 방안을 모색하고자 각 두 종류의 정보 전달 매체와 설명 방식의 조합인 4개의 서로 다른 트레이닝 설계의 학습 효과를 비교한다. 피험자 간 설계 실험으로 4개의 트레이닝 설계의 효과를 비교 분석한다. 둘째, 키오스크에 설치 가능한 설계 특성 (좌우 칸막이, 뒤 칸막이, 의자)이 키오스크 사용자의 작업 수행도와 작업부하에 미치는 영향을 평가한다. 그 결과 본 논문에서는 고령인의 키오스크 접근성 향상을 위한 효과적인 트레이닝을 설계하기 위해서는 어떤 정보 전달 매체와 설명 방식을 선택해야 하는지, 공공 키오스크의 전반적인 사용자 경험을 개선하기 위해서는 어떤 설계 특성을 설치해야 하는지에 대한 가이드라인을 제공한다.Abstract ii Contents iv List of Tables vii List of Figures viii Chapter 1 Introduction 1 1.1 Research Background 1 1.2 Research Objective and Questions 3 1.3 Structure of the Thesis 4 Chapter 2 Training Design for Helping Older Adults Use Public SSK 5 2.1 Introduction 5 2.2 Method 9 2.2.1 Participants 9 2.2.2 Experimental Procedure 9 2.2.3 Training Methods Design 11 2.2.4 Independent and Dependent Variables 14 2.2.5 Data Analyses 16 2.3 Results 17 2.3.1 General Training Effects 17 2.3.2 Training Method Effects 10 2.3.3 Training Time 21 2.4 Discussion 21 2.4.1 General Training Effects 22 2.4.2 Training Method Effects 23 2.4.3 Implications 26 Chapter 3 An Investigation of SSK Design: A Partition and Chair Effects on Perceived Workloads and Task Performance 29 3.1 Introduction 29 3.2 Method 35 3.2.1 Participants 35 3.2.2 Experimental Setup 36 3.2.3 Design Alternatives 36 3.2.4 Experimental Task 37 3.2.5 Experimental Procedure 38 3.2.6 Independent and Dependent Variables 40 3.2.7 Data Analyses 42 3.3 Results 43 3.3.1 General and Generalized Linear Model Analyses 43 3.3.1.1 Design Effects: Main and Interaction Effects on Design Variables 46 3.3.1.2 Age Group Differences in Design Effects 48 3.3.2 Comparison of Design Alternatives 50 3.3.3 Correlation Analyses 51 3.4 Discussion 53 3.4.1 Design Effects: Main and Interaction Effects of Design Variables 54 3.4.2 Age Group Differences in Design Effects 60 3.4.3 Correlation Analyses 63 3.4.4 Implications 64 Chapter 4 Conclusion 66 4.1 Summary and Implications 66 4.2 Future Research Directions 67 Bibliography 69 국문초록 82석

Evaluation of a ChromID C. difficile Agar for the Isolation of Clostridium difficile.

BACKGROUND: Clostridium difficile is the main etiologic agent of antibiotic-associated diarrhea and the most common cause of hospital-acquired diarrhea. Recently, the incidence of C. difficile infections (CDI) has increased and new highly virulent C. difficile strains have emerged. Therefore, accurate and rapid diagnosis is needed. We compared the results of using chromID C. difficile (chromID CD, bioMerieux, France) with the conventional C. difficile Selective Agar (CDSA; BD, USA) for the isolation of C. difficile. METHODS: A total of 738 stool specimens of suspected CDI patients at the Severance Hospital from July to August 2011 were inoculated onto CDSA. Among them, 104 stool specimens revealed colonies on CDSA that were then re-inoculated onto chromID CD. The stool samples were stored at -20degrees C until the time of the re-inoculation. Cultured agars were interpreted after 24 hrs and 48 hrs, respectively. Species identification was performed on the basis of colony characteristics on agar plates as well as the ATB 32A system (API System SA, France). RESULTS: The recovery rates of CDSA and chromID CD were 30.1% and 77.5% after 24 hrs, and 77.5% and 98.6% after 48 hrs, respectively. All of the C. difficile isolates were recovered as typical gray/black colonies on chromID CD. CONCLUSION: The performance of chromID CD for the isolation of C. difficile was better than that of conventional CDSA. The chromID CD could provide easy and sensitive detection of C. difficile even after 24hrs of incubation.ope

Recognition of a Pseudo-Outbreak of Cladosporium Species by Continuous Monitoring of Culture Results

BACKGROUND: Cladosporium spp. are dematiaceous fungi that are commonly isolated from indoor and outdoor environments, including hospital air. This fungus is rarely pathogenic to humans, but has been reported to cause infections of the skin and toenails, as well as sinusitis and pulmonary infections. The monitoring of culture results was conducted to identify the outbreak of an unknown black fungal infection between January and March 2006 in a University hospital, and infection control activity was performed to identify the cause of the outbreak. METHODS: An epidemiological investigation of 22 patients with infections caused by an unknown black fungus was conducted. Microscopic examination and molecular analysis on the internal transcript spacer (ITS) region was performed to identify the black fungus. To detect the source of contamination, a culture of environmental specimens was performed, and then, disinfection of the laboratory was implemented. RESULTS: The patients with black fungi belonged to various departments and wards. No symptoms of fungal infection were recognized on the basis of the survey. The black fungus was identified as Cladosporium spp. on the basis of morphological features and ITS region sequencing. Culturing of environmental specimens was performed in the laboratory. Black fungi were isolated from a specimen from a rack and had the same morphological features with Cladosporium spp. from clinical specimens. After the rack was autoclaved, Cladosporium spp. from clinical specimens was no longer isolated. CONCLUSION: Epidemiological investigation, microscopic examination, and molecular analysis revealed that the sudden increase in the isolation rate of Cladosporium spp. from clinical specimens was the result of a pseudo-outbreak caused by the contamination of a rack. To our knowledge, this is the first report of a pseudo-outbreak of Cladosporium spp. Continuous monitoring of culture results is important to avoid unnecessary labor for nosocomial infection controlope

Chromosomal cephalosporinase in Enterobacter hormaechei as an ancestor of ACT-1 plasmid-mediated AmpC β-lactamase

In this study of the diversity of AmpC β-lactamase in clinical isolates of Enterobacter spp., a strain was found carrying the plasmid-mediated AmpC β-lactamase ACT-1 gene on its chromosome. The strain was identified as Enterobacter hormaechei using phylogenetic analysis of 16S rRNA and hsp60 genes. In addition, the species was confirmed by DNA-DNA hybridization. The genetic environment of the bla(ACT-1) gene was characterized, including the ampR and ampG genes, using a two-step PCR. The amino acid sequences of AmpR at serine 35, arginine 86, glycine 102, aspartic acid 135 and tyrosine 264 were conserved. Measurement of the transcription level of the bla(ACT-1) gene using real-time quantitative PCR showed that it increased 1.98-fold following cefoxitin induction. These results suggest that the plasmid-mediated bla(ACT-1) gene originated from the chromosome of E. hormaechei.ope

In Vitro Activities of Ceftriaxone-Sulbactam against Major Aerobic and Anaerobic Bacteria from Clinical Samples.

BACKGROUND: beta-lactam antibiotics are one of the most common antimicrobial agents. However, the increasing of beta-lactamase-producing bacteria makes these agents less useful. Therefore, agents stable for beta-lactamase have been developed. This study was conducted to determine the activities of the combination agent ceftriaxone-sulbactam and to compare its activities with other agents. METHODS: A total of 437 clinical isolates of aerobic and anaerobic bacteria were collected in Severance Hospital from 2007 to 2011. Using 23 antimicrobial agents, antimicrobial susceptibility tests were performed using the Clinical and Laboratory Standards Institute (CLSI) agar dilution method. RESULTS: The minimal inhibitory concentrations (MICs) of ceftriaxone and ceftriaxone-sulbactam were similar to or lower than those of other beta-lactam antibiotics for methicillin-susceptible Staphylococcus aureus (MSSA), Streptococcus pneumoniae, S. pyogenes, and viridans group streptococci. For Moraxella catarrhalis, Neisseria gonorrhoeae, Haemophilus influenzae, and H. parainfluenzae, ceftriaxone and the ceftriaxone-sulbactam combination also show low MIC50 and MIC90. For extended-spectrum beta-lactamase (ESBL)-producing E. coli, the MICs of ceftriaxone-sulbactam were lower than those of other cephalosporins. Among the anaerobes, ceftriaxone-sulbactam showed good activity compared to ceftriaxone alone for the Bacteroides fragilis group, B. thetaiotaomicron, other Bacteroides sp., Prevotella sp., and Porphyromonas sp. CONCLUSIONS: Ceftriaxone-sulbactam showed good antimicrobial activity and thus is useful for the treatment of infections by MSSA, S. pneumoniae, S. pyogenes, viridans group streptococci, M. catarrhalis, N. gonorrhoeae, H. influenzae, H. parainfluenzae, E. coli, and K. pneumoniae, B. fragilis group, B. thetaiotaomicron, other Bacteroides sp., Prevotella sp., and Porphyromonas spope

A Case of Catheter-Related Bloodstream Infection by Tsukamurella inchonensis in a Pediatric Patient Receiving Home Intravenous Antibiotic Treatment.

Bacteria belonging to the genus Tsukamurella are aerobic, gram-positive rods that are weakly acid-fast with no apparent branching. Infections of the Tsukamurella spp. are generally caused by the use of infected medical devices such as central venous catheters. The underreporting of these infections might be attributable to the frequent misdiagnosis of Tsukamurella infections as Corynebacterium or atypical Mycobacterium spp. infections. Therefore, when gram-positive aerobic rods are observed in the blood culture of a patient with a central venous catheter, it is important to consider Tsukamurella as one of the causative organisms. Here, we report the first case of a catheter-related blood stream infection caused by Tsukamurella inchonensis in a 3-yr-old Korean girl with underlying biliary atresia who underwent hepatoportoenterostomy.ope

A Korean Nationwide Surveillance Study for Non-Typhoidal Salmonella Isolated in Humans and Food Animals from 2006 to 2008: Extended-Spectrum β-Lactamase, Plasmid-Mediated AmpC β-Lactamase, and Plasmid-Mediated Quinolone Resistance qnr Genes

Background: The emergence of non-typhoidal Salmonella (NTS) with decreased susceptibilities to fluoroquinolone, ampicillin, or ceftriaxone has been reported worldwide. However, current surveillance studies of resistance among NTS in Korea are limited. Thus, the antimicrobial susceptibilities; resistance mechanisms such as extended-spectrum β-lactamase (ESBL), plasmid-mediated AmpC β-lactamase (PABL), and plasmid-mediated quinolone resistance (PMQR); and molecular epidemiologic characteristics were investigated in the present study. Methods: National Institute of Health and National Veterinary Research and Quarantine Service collected NTS strains from 219 clinical and 293 non-clinical specimens from 2006 to 2008. The antimicrobial susceptibilities were determined using the Clinical and Laboratory Standards Institute disk diffusion test. ESBL, PABL, and qnr genotyping were performed using PCR and nucleotide sequencing. Pulsed-field gel electrophoresis was used for the molecular epidemiologic study. Results: The resistance to ampicillin in clinical and non-clinical NTS was 49% and 18 to 47%, respectively. The resistance rates to trimethoprim-sulfamethoxazole in clinical and non-clinical NTS were 8% and 0 to 41%, respectively. The rates to extended-spectrum cephalosporin were 0 to 1%. One CTX-M-15-producing isolate and four CMY-2-producing isolates were detected. Notably, PFGE analysis showed four isolates carrying blaCMY-2, including one non-clinical strain had high clonality. Although the rate of ciprofloxacin resistance was very low, two qnrS1-carrying NTS strains were detected in non-clinical specimens. Conclusion: The resistance rates to ampicillin in both clinical and non-clinical NTS were high, while those to trimethoprim-sulfamethoxazole varied depending on the specimen. NTS strains harboring CTX-M-15-type ESBL or CMY-2-type PABL were detected even though the resistance rates to cephalosporins were very low. Four NTS strains carrying the blaCMY-2-gene implied zoonotic infection. Continuous effort to minimize transfer of resistance genes in NTS is necessary.ope

Antimicrobial susceptibility of Stenotrophomonas maltophilia isolates from a Korean tertiary care hospital

We determined the antimicrobial susceptibility of 90 clinical isolates of Stenotrophomonas maltophilia collected in 2009 at a tertiary care hospital in Korea. Trimethoprim-sulfamethoxazole, minocycline, and levofloxacin were active against most of the isolates tested. Moxifloxacin and tigecycline were also active and hold promise as therapeutic options for S. maltophilia infections.ope

Subcutaneous phaeohyphomycosis caused by Phaeoacremonium species in a kidney transplant patient: the first case in Korea.

Phaeohyphomycosis is a subcutaneous infection caused by dark pigmented fungi, including fungi of the species Phaeoacremonium, Alternaria, Exophiala, and Pyrenochaeta. In August 2005, a 54-yr-old man who had received a renal transplant 5 yr ago was admitted to our hospital with a subcutaneous mass on the third finger of the right hand; the mass had been present for several months. He had been receiving immunosuppressive agents for several years. He underwent excision of the mass, which was followed by aspiration of the wound for bacterial and fungal cultures. Many fungal hyphae were observed on the histology slide treated with periodic acid-Schiff stain. A few white waxy colonies with a woolly texture grew on the Sabouraud dextrose agar at 30°C and changed to dark brown in color. Nucleotide sequencing of internal transcribed spacer regions revealed 100% homology to the Phaeoacremonium aleophilum anamorph and Togninia minima teleomorph (514 bp/514 bp). The patient completely recovered after wide surgical excision. Here, we report the first case of phaeohyphomycosis caused by Phaeoacremonium species in a kidney transplant patient in Koreaope

Evaluation of an Automated Instrument, PREVI Isola® for Inoculation of Body Fluids and Urine Samples onto Agar Plates

Background: In most clinical microbiology laboratories, inoculation of specimens on plates is performed manually and is a time-consuming process. The efficiency of this process can be improved by using an automated instrument. Currently, several automated instruments have been introduced for inoculation of samples. In this study, we have evaluated an automated instrument, PREVI Isola® (Biomerieux, France), used for inoculation of body fluids and urine specimens. Methods: Both manual and automated instrument methods were used to inoculate 74 body fluid and 204 urine samples. Precision was evaluated by testing 3 types of urine samples (A, 6×103 colony-forming units (CFU)/mL; B, 3×104 CFU/mL; and C, >106 CFU/mL) in replicates of 20. Results of the 2 methods were compared by counting the isolated colonies on agar plates after incubation. The time required for both methods was also compared. Results: The coefficient of variation (CV) of samples A, B, and C examined using the automated instrument method was 176.1%, 18.1%, and 12.6%, respectively. The sensitivity and specificity of testing body fluid samples were 77% and 100%, respectively, and those of urine samples were 87% each. The time required for testing 15 body fluid specimens and that for inoculation of each specimen was 9.7 min shorter using PREVI Isola® than using the manual method. Conclusions: The results of body fluid and urine culture by inoculation using the automated instrument, PREVI Isola®, showed relative good agreement with those obtained using the manual method. The use of PREVI Isola® would be expected to reduce the time and labor involved in inoculating various kinds of specimens.ope