• Title/Summary/Keyword: Mann-Whitney U test

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Environmental Equity Analysis of the Accessibility to Public Transportation Services in Daegu City (대구시 대중교통서비스의 접근성에 대한 환경적 형평성 분석)

  • Kim, Ah-Yeon;Jun, Byong-Woon
    • Journal of the Korean Association of Geographic Information Studies
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    • v.15 no.1
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    • pp.76-86
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    • 2012
  • The purpose of this study is to investigate the environmental equity of the accessibility to public transportation services in the city of Daegu. The 2005 census data as well as bus stop and subway station datasets were integrated for building the GIS database. Public transportation service areas were then identified by a coverage method. Mann Whitney U test was used for statistically comparing the socioeconomic characteristics over different levels of access to the public transportation services. Both Dong-gu, Suseong-gu, Dalseo-gu, and Buk-gu located outside of the city had worse accessibility than others while Jung-gu, Seo-gu, and Nam-gu had better accessibility than others. There appeared no environmental inequity pattern in terms of the percentages of men, women, and teenagers over the city of Daegu whereas there existed some environmental inequity pattern in terms of the percentages of people above the age of 65 and people below poverty line. This environmental inequity pattern would be caused by some factors. Firstly, the lower income class has tended to reside in the declined or blighted areas far away from public transportation facilities since this class can not afford to pay expensive rents and land prices around the main roads with higher accessibility. Many old people belonging to the lower income class also reside in the declined or blighted areas. Secondly, there has been no law to locate bus stops and subway stations considering residents' socioeconomic characteristics and the spatial distribution of public transportation facilities has been not managed systematically by the city government. This research would shed insight on building the public transportation policy to locate bus stops and subway stations and to select the routes of buses and subways considering the spatial distribution of residents' socioeconomic characteristics.

Spatial Ability, Its Relationship to Mathematics Achievement, and Strategic Choices for Spatial Tasks Among Engineering Freshmen, and Gender Differences (공과대학 신입생들의 공간 시각화 능력의 수학 성취도와의 관계와 문제해결 전략 및 성별 차이에 관한 연구)

  • Kim, Yon Mi
    • Korean Journal of Cognitive Science
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    • v.28 no.3
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    • pp.149-171
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    • 2017
  • In this research, based on the fact that spatial ability is important for the achievement in the STEM fields, and technological innovation, Purdue Spatial Visualization Test-Rotation has been used to investigate engineering freshmen's spatial ability and gender differences. Students who have taken advanced mathematics courses in high school(those who have taken type B math test in Korean SAT test) and students with general math courses(those who have taken type A in Korean SAT-Math test) are included in this study to find out the relationship between mathematics achievement and spatial ability. Finding out the strategies taken by students was another aim of this study. This strategic differences between high achievers and lower achievers, male and female students were analyzed from students' self report. Spatial ability test score was highest in the SAT-Math type B male students, decreased in the order of type A male students, type B female students, and lastly type A female students. There was no substantial difference between second and third groups. In each group, male students' average score was 8~10% higher than female students, which affirms 2015's results. The correlation between spatial ability and mathematics achievement was negligible in each group, but male students' math score and spatial ability score were higher than that of female students. This can be interpreted that there is some correlation between these two. Strategic choices can vary in the continuous spectrum with analytic method and holistic method at both ends. From students' self report, using Mann-Witney test, it turned out that there exists strategic differences between male and female students. Male students have a tendency to use holistic strategy more often than female students. I also found that the strategy choice did not vary greatly among all score groups. For the perfect score groups, both female and male students used holistic strategy most frequently. For low achieving groups, there is an evidence that these students overuse one method compared to average or high achieving groups, which turned out to be less effective. Based on these, I suggest that low achieving students need to have more chances to adopt efficient strategies and to practice challenging problems to improve their spatial abilities.

Spawning Patterns of Three Bitterling Fishes (Pisces: Acheilognathinae) in Relation to the Shell Size of Host Mussels (Unio douglasiae sinuolatus) (납자루아과(Pisces: Acheilognathinae) 담수어류 3종의 숙주조개(작은말조개; Unio douglasiae sinuolatus) 크기에 대한 산란양상)

  • Choi, Hee-kyu;Lee, Hyuk Je
    • Korean Journal of Environment and Ecology
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    • v.33 no.2
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    • pp.202-215
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    • 2019
  • This study was conducted to investigate the spawning preference of the Acheilognathinae fishes in relation to the shell size of host mussels after identifying the species of eggs and fries in the host mussel using our recently developed RFLP (Restriction Fragment Length Polymorphism) molecular marker at four sites [Hongcheon Naechoncheon (HN) and Deokchicheon (HD) from the North Han River basin and Jeongseon Goljicheon (JG) and Joyanggang (JJ) from the South Han River] in South Korea during May in each year between 2015 and 2018. The Acheilognathinae fish observed in the studied sites included one species (Acheilognathus signifer) in HN and JG, three species (Rhodeus uyekii, A. signifer, and Acheilognathus yamatsutae) in HD, and two species (A. signifer and Acheilognathus yamatsutae) in JJ, and we collected 982 host mussels (Unio douglasiae sinuolatus) that inhabited in all four sites. Using the RFLP molecular marker, we confirmed 46 eggs and fry of the Acheilognathinae fish (454 A. signifer, 43 Acheilognathus yamatsutae, and 149 Acheilognathus yamatsutae) in Unio douglasiae sinuolatus (N=163; 16.6%). We compare the average shell length, shell height, and shell width of mussels with [presence] eggs/fry and mussels without [absence] eggs/fry to examine the spawning preference according to the size of host mussels in each site. The results show that the shell length (1.98 mm), shell height (0.85 mm), and shell width (0.73 mm) of mussels with the eggs/fry were significantly larger (Mann-Whitney U test, P=0.002; difference=1.98 mm) than those of mussel without eggs/fry in HD where three species cohabitated. Although the shell length, shell height, and shell width of mussels with the eggs/fry were larger also in the other three sites, the difference was not statistically significant. In addition, we analyzed the mean number of spawned eggs and fry of each species and found $9.31{\pm}5.94$ R. uyekii, $2.86{\pm}2.45$ A.signifer, and $2.50{\pm}1.32$ A. yamatsutae. R. uyekii spawned 6.45-6.81 more eggs than A.signifer and A. yamatsutae on average per mussel, and it was statistically significant (Kruskal-Wallis test, P < 0.001). These findings indicate that the three species of Acheilognathinae fish tend to prefer larger mussels as their spawning hosts, and this tendency increases when the number of cohabitating bitterling fish species increases. Moreover, A.signifer and A. yamatsutae spawned a smaller number of eggs evenly in more host mussels while R. uyekii spawned many eggs on relatively fewer mussels. We found mussels (N=4) having the eggs/fry of two coexisting species, A. signifier and A. yamatsutae in HD and JJ where more than two bitterling fish species occurred. It suggests the interspecific competition taking place between the Acheilognathinae fishes for utilizing the same resource of mussels for spawning when two or more species cohabitate. This study is expected help to understand better the spawning patterns and reproductive ecology of the Acheilognathinae fishes, which will provide insightful information for advancing our understanding of their ecological relationships - mutualism or host-parasitism - with host mussels.

Effect of endurance exercise during acute stage on hindlimb muscles of stroke induced rat (지구력 운동이 급성기 뇌졸중 쥐의 뒷다리근 질량에 미치는 영향)

  • An, Gyeong-Ju;Lee, Yoon-Kyong;Im, Ji-Hae;Choi, S-Mi;Choe, Myoung-Ae
    • Journal of Korean Biological Nursing Science
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    • v.2 no.2
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    • pp.67-80
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    • 2000
  • The purpose of this study was to identify hindlimb muscle atrophy in stroke induced rat and determine the effect of endurance exercise on body weight, weight of hindlimb muscle during 7 days after stroke induction. Thirty four male Sprague-Dawley rats with 200-270g body weight were divided into four groups : control, control+exercise(Con+Ex), stroke, and exercise after stroke(St+Ex) group. The control group and Con+Ex group received sham operation and the stroke group and St+Ex group received right MCA occlusion operation by using silicon-coated probe. The Con+Ex and St+Ex groups ran on a treadmill for 20min/day at 10m/min and $10^{\circ}grade$. Daily body weight and diet intake were measured every morning for 7 days. Cerebral infarction of stroke and St+Ex groups were identified by staining with TCC for 30minutes. The data were analyzed by Kruskal-Wallis test and Mann-Whitney U test using the SPSSWIN 9.0 program. Body weight of the control group at the 7th day increased by 18.3% significantly from the first day of experiment, that of the stroke group at the 7th day decreased by 6.7% significantly compared to the day of receiving right MCA occlusion operation. Body weight of the Con+Ex group at the 7th day increased by 10.3% significantly form the first day of experiment, that of St+Ex group at the 7th day also increased by 13.4% significantly compared to the day of receiving right MCA occlusion operation. The total amount of diet in stroke group decreased significantly compared to that of St+Ex and that of control group. In stroke group the wet weight of both sides of soleus, plantaris, and gastrocnemius muscles decreased significantly compared to that of control group. The relative weight of affected(left) plantaris and gastrocnemius muscles decreased significantly compared to that of the control group. The difference between the weight of affected and unaffected soleus, plantaris, and gastrocnemius muscles were not significant in stroke group. The wet weight of right gastrocnemius muscles in Con+Ex group increased compared to that of control group. The relative weight of right gastrocnemius muscle increased significantly compared to that of the control group. The wet weight of St+Ex group increased significantly compared to that of the stroke group in both sides of soleus, plantaris, and gastrocnemius muscles. The relative weight of affected plantaris muscle increased significantly compared to that of the stroke group. The difference between the weight of affected and unaffected soleus, plantaris, and gastrocnemius muscles were not significant in St+Ex group. Body weight and wet weight of soleus, plantaris, and gastrocnemius muscles in the St+Ex group did not recover to the values of control group. Based on these results, it can be suggested that endurance exercise during acute stage of stroke can reduce muscle atrophy related to denervation, inactivity and undernutrition.

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Influence of Menstrual Cycle on Inflammatory Markers in Gingival Crevicular Fluid : Pilot Study (월경주기에 따른 치은열구액 내 염증지표의 변화: 예비 연구)

  • Park, Hoo-Seob;Hwang, Soo-Jeong;Cho, Min-Jeong;Kim, Do-Kyoung;Yang, Seon-Youn
    • Journal of dental hygiene science
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    • v.12 no.1
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    • pp.71-77
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    • 2012
  • Sex Hormones exert significant influence in body physiology throughout life. Some reports suggested increased sex hormone levels correlate with an increased prevalence of gingivitis. The objectives of this pilot study are to(1) address the link between menstrual cycle and MMP-9, MMP-8, IL-$1{\beta}$ of gingival crevicular fluid during 4 weeks and (2) discuss the major biomarker of periodontal status. 7 female and 3 male volunteer who didn't have smoking habit, medical and dental disease after informed consent, were seen twice a week for 4 weeks. GCF samples were collected and GCF levels of MMP-9, MMP-8, IL-$1{\beta}$ were measured by enzyme-linked immunosorbent assay. The GCF levels of MMP-9, MMP-8, IL-$1{\beta}$ had fluctuation according to menstrual cycle, but the changes of those were not significant by Friedman matched samples test. There is no difference between female and male subjects by Mann-Whitney U test. The correlation of MMP-8, MMP-9 and IL-$1{\beta}$ showed strong by Spearman correlation(0.644-0.945). This study confirms menstrual cycle doesn't influence the periodontium of healthy female subjects.

Preliminary three-dimensional analysis of tooth movement and arch dimension change of the maxillary dentition in Class II division 1 malocclusion treated with first premolar extraction: conventional anchorage vs. mini-implant anchorage

  • Park, Heon-Mook;Kim, Byoung-Ho;Yang, Il-Hyung;Baek, Seung-Hak
    • The korean journal of orthodontics
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    • v.42 no.6
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    • pp.280-290
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    • 2012
  • Objective: This study aimed to compare the effects of conventional and orthodontic mini-implant (OMI) anchorage on tooth movement and arch-dimension changes in the maxillary dentition in Class II division 1 (CII div.1) patients. Methods: CII div.1 patients treated with extraction of the maxillary first and mandibular second premolars and sliding mechanics were allotted to conventional anchorage group (CA, n = 12) or OMI anchorage group (OA, n = 12). Pre- and post-treatment three-dimensional virtual maxillary models were superimposed using the best-fit method. Linear, angular, and arch-dimension variables were measured with software program. Mann-Whitney U-test and Wilcoxon signed-rank test were performed for statistical analysis. Results: Compared to the CA group, the OMI group showed more backward movement of the maxillary central and lateral incisors and canine (MXCI, MXLI, MXC, respectively; 1.6 mm, p < 0.001; 0.9 mm, p < 0.05; 1.2 mm, p < 0.001); more intrusion of the MXCI and MXC (1.3 mm, 0.5 mm, all p < 0.01); less forward movement of the maxillary second premolar, first, and second molars (MXP2, MXM1, MXM2, respectively; all 1.0 mm, all p < 0.05); less contraction of the MXP2 and MXM1 (0.7 mm, p < 0.05; 0.9 mm, p < 0.001); less mesial-in rotation of the MXM1 and MXM2 ($2.6^{\circ}$, $2.5^{\circ}$, all p < 0.05); and less decrease of the inter-MXP2, MXM1, and MXM2 widths (1.8 mm, 1.5 mm, 2.0 mm, all p < 0.05). Conclusions: In treatment of CII div.1 malocclusion, OA provided better anchorage and less arch-dimension change in the maxillary posterior teeth than CA during en-masse retraction of the maxillary anterior teeth.

Effect of regular exercise during recovery period following steroid treatment on the atrophied hindlimb muscles induced by steroid in rats (스테로이드 치료 후 회복기의 규칙적인 운동이 쥐의 스테로이드 유발성 위축 뒷다리근에 미치는 영향)

  • Choe, Myoung-Ae;Byun, Young-Soon;Hwang, Ae-Ran;Kim, Hee-Seung;Hong, Hae-Sook;Choi, S-Mi;Seo, Wha-Sook;Lee, Kyung-Sook;Park, Mi-Jung;Shin, Gi-Soo;An, Gyeong-Ju;Lee, Yoon-Kyoung;Im, Ji-Hae
    • Journal of Korean Biological Nursing Science
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    • v.4 no.1
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    • pp.85-99
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    • 2002
  • This study was conducted to determine whether low intensity regular exercise following steroid treatment could attenuate steroid-induced muscle atrophy. Thirty-eight Sprague-Dawley rats weighing $165{\sim}175g$ were divided into six groups ; control group(C), dexamethasone administration group(D), sedentary normal saline administration group(C+Se), exercise after normal saline administration group(C+Ex), sedentary group after dexamethasone administration(D+Se), exercise group after dexamethasone administration(D+Ex). Either dexamethasone(5mg/kg) or normal saline was injected for 7days accordingly. Exercise was started at 10m/min on the $10^{\circ}$ grade treadmill and gradually increased up to 15m/min by the 7th day for 60minutes/day($20min{\times}3$). The data were analyzed by Kruskal-Wallis test and Mann-Whitney U test using the SPSS WIN 9.0 program. Body weight, muscle weight and myofibrillar protein content of both plantaris and gastrocnemius, Type I, II muscle fiber cross-sectional area of plantaris, and Type II muscle fiber cross-sectional area of gastrocnemius in D group were significantly lower than those of C group(p<0.05) respectively. Hindlimb muscle weight, myofibrillar protein content of both plantaris and gastrocnemius. Type I muscle fiber cross-sectional area of soleus and Type I, II muscle fiber cross-sectional area of plantaris in D+Ex group tended to increase compared to those of D+Se group. Myofibrillar protein content of both plantaris and gastrocnemius, Type I muscle fiber cross-sectional area of plantaris in D+Ex group tended to increase compared to those of C+Se group. Based on these results, it is suggested that regular low-intensity exercise during recovery period after steroid treatment might facilitate the recovery from steroid-induced muscle atrophy.

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Effect of exercise during acute stage of stroke on affected and unaffected hindlimb muscle mass of cerebral ischemic rat (뇌졸증 후 급성기 운동이 뇌허혈 유발쥐의 뒷다리근 질량에 미치는 영향)

  • Im, Ji-Hye;Choe, Myoung-Ae
    • Journal of Korean Biological Nursing Science
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    • v.4 no.1
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    • pp.51-69
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    • 2002
  • The purpose of this study was to identify the effect of cerebral ischemia on affected(Lt) and unaffected(Rt) side of soleus, plantaris and gastrocnemius muscle mass and determine the effect of exercise on affected and unaffected side on soleus, plantaris and gastrocnemius muscle mass during acute stage of stroke. Sixteen male Sprague-Dawley rate with 200-270g body weight were randomly divided into three groups: control, stroke, and exercise after stroke(St+Ex) group. The control group received sham operation and the stroke group and St+Ex group received transient right MCA(middle cerebral artery) occlusion operation. The St+Ex groups ran on a treadmill for 20min/day at 10m/min and $10^{\circ}$ grade for 6days. During the experimental period body weight and diet intake was measured every morning. On the 7th day after operation, muscles were dissected from both affected and unaffected side of hindlimb. Cerebral infarction of stroke and St+Ex groups were identified by staining with TCC for 30 minutes. The data were analyzed by Kruskal-Wallis test and Mann-Whitney U test using the SPSSWIN 9.0 program. Significance was accepted at the level of p<0.05. The results were summarized follows : 1) There were no significant difference of the body weight on the first day of experiment among 3 groups. Whereas on the 7th day, the body weight of both stroke group and St+Ex group were significantly smaller than that of control group. Body weight of St+Ex group on the 7th day tended to be larger than that of stroke group. 2) Total diet intake of both stroke group and St+Ex group were also significantly smaller than that of control group. While total amount of diet intake in St+Ex group tended to be larger than that of stroke group. 3) The weight of gastrocnemius muscle of affected side in stroke group significantly decreased compared to that of control group and the weight of soleus and plantaris muscle of affected side in stroke group tended to decrease compared to that of control group. 4) The weight of plantaris muscle of unaffected side in stroke group significantly decreased compared to that of control group and the weight of soleus and gastrocnemius muscle of unaffected side in stroke group tended to decrease compared to those of control group. 5) The weight of gastrocnemius muscle of affected side in stroke group significantly decreased compared to that of unaffected side and there was no significant difference of the weight of soleus and plantaris muscle in stroke group between affected side and unaffected side. 6) The weight of soleus, plantaris and gastrocnemius muscle of both affected side and unaffected side in St+Ex group had a tendency of increase compared to those of stroke group. The relative weight of soleus and gastrocnemius muscle of affected side and soleus muscle of unaffected side in St+Ex group had a tendency to increase compared to those of stroke group. Based on these results, exercise during acute stage of stroke might attenuate muscle atrophy of both affected and unaffected side of hindlimb muscles.

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Retrospective long-term analysis of bone level changes after horizontal alveolar crest reconstruction with autologous bone grafts harvested from the posterior region of the mandible

  • Voss, Jan Oliver;Dieke, Tobias;Doll, Christian;Sachse, Claudia;Nelson, Katja;Raguse, Jan-Dirk;Nahles, Susanne
    • Journal of Periodontal and Implant Science
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    • v.46 no.2
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    • pp.72-83
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    • 2016
  • Purpose: The goal of this study was to evaluate the long-term success of horizontal alveolar crest augmentation of the retromolar region of the mandible with particulated bone, as well as factors affecting subsequent peri-implant bone loss. Methods: A total of 109 patients (68 female, 41 male) suffering from alveolar ridge deficiencies of the maxilla and mandible were included in this study. All patients were treated with particulated retromolar bone grafts from the mandible prior to the insertion of endosseous dental implants. Mesial and distal peri-implant crestal bone changes were assessed at six time points. Several parameters, including implant survival and the influence of age, gender, localisation of the implant, diameter, covering procedures, and time points of implant placement, were analysed to identify associations with bone level changes using the Mann-Whitney U-test, the Kruskal-Wallis test, and Spearman's rank-order correlation coefficient. Results: A total of 164 dental implants were placed in the maxilla (n=97) and in the mandible (n=67). The mean observation period was $105.26{\pm}21.58$ months after implantation. The overall survival rate was 97.6% after 10 years. Overall, peri-implant bone loss was highest during the first year, but decreased over time. The mean amount of bone loss after 10 years was 2.47 mm mesially and 2.50 mm distally. Bone loss was significantly influenced by implant type and primary stability. Conclusions: The use of particulated autologous retromolar bone grafts is a reliable technique for the horizontal reconstruction of local alveolar ridge deficiencies. Our results demonstrate that implants placed in augmented bone demonstrated similar bone level changes compared to implants inserted in non-augmented regions.

Prognostic Factor, for Major Trauma Patients in the Emergency Medical Service System (응급의료전달체계의 각 요인이 중증외상환자의 예후에 미치는 영향 분석)

  • Lim, Du-Ko;Chung, Tae-Nyoung;Lee, Chang-Jae;Jin, Su-Guun;Kim, Eui-Chung;Choi, Sung-Wook;Kim, Ok-Jun
    • Journal of Trauma and Injury
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    • v.24 no.2
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    • pp.89-94
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    • 2011
  • Purpose: A few studies have assessed the factors affecting the prognoses for major trauma patients and those improving the circumstances when dealing with the trauma system. In that light, we analyzed factors, such as pre-hospital factors, the time to admission, the length of stay in the emergency department (ED) and emergency operation, influencing the outcomes for trauma patients. Methods: The patients who visited our emergency department from April 1, 2009, to February 29, 2011, due to major trauma were enrolled in the study. The inclusion criterion was a revised trauma score (RTS) < 7 or injury severity score (ISS) ${\geq}$ 16. We used reviews of medical records, to analyze each step of emergency medical care with respect to patients' sex, age, visit time and visit date. Continuous variables were described as a median with an interquartile range, and we compared the variables between the survival and the mortality groups by using the Mann-Whitney U test. Fisher's exact test was used for nominal variables. Using the variables that showed statistical significance in univariate comparisons, we performed a logistic regression analysis, and we tested the model's adequacy by the using the Hosmer-Lemeshow method. Results: A total of 261 patients with major trauma satisfied either the RTS score criterion or the ISS score criterion. Excluding 12 patients with missing data, 249 patients were included in this study. The overall mortality rate was 16.9%. Time to ED arrival, time to admission, time of ED stay, RTS, ISS, and visit date being a holiday showed statistically significant differences between the survival and the mortality groups in the univariate analysis. RTS, ISS, length of ED stay, and visit date being a holiday showed statistical significance in the multivariate analysis. Conclusion: The mortality rate did not show a significant relationship with the time to ED arrival, use of 119, on time to admission. Rather, it elicited a quite significant correlation with the trauma scoring system (RTS and ISS), the time of ED stay, and the visit date being a holiday.