• The Bulletin of The Korean Astronomical Society
• /
• v.44 no.1
• /
• pp.39.1-39.1
• /
• 2019

Not all stars in the Universe are gravitationally bounded to galaxies. Since first discovered in 1951, observations have revealed that a significant fraction of stars fills the space between galaxies in local (low-redshift) galaxy clusters, observed as diffuse intracluster light (ICL). Theoretical models provide mechanisms for the production of intracluster stars as tidally stripped material or debris generated through numerous galaxy interactions during the hierarchical growth of the galaxy cluster. These mechanisms predict that most intracluster stars in local galaxy clusters are long-accumulated material since z~1. However, there is no observational evidence to verify this prediction. Here we report observations of abundant ICL for a massive (above $10^{14}$ solar masses) galaxy cluster at a redshift of z=1.24, when the Universe was 5 billion years old. We found that more than 10 per cent of the total light of the cluster is contributed by the diffuse ICL out to 110 kpc from the center of the cluster, comparable to 5-20 per cent in local, massive galaxy cluster. Furthermore, we found that the colour of the brightest cluster galaxy located in the core of the cluster is consistent with that of the ICL out to 200 kpc. Our results demonstrate that the majority of the intracluster stars present in the local Universe, contrary to most previous theoretical and observational studies, were built up during a short period and early (z>1) in the history of the Virgo-like massive galaxy cluster formation, and might be concurrent with the formation of the brightest cluster galaxy.

• The Bulletin of The Korean Astronomical Society
• /
• v.43 no.2
• /
• pp.32.1-32.1
• /
• 2018

The galactic warp is almost ubiquitous among disk galaxies and suspected to be an imprint of recent interactions with other galaxies. The detailed evolutionary course, however, is still uncertain due to the lack of observational evidence. To address this issue, we construct a new extensive catalog of 412 conspicuously warped disks at z = 0.01 ~ 0.05, based on SDSS DR7. We classify the warp morphology through a visual inspection from the Zooniverse Project and our new automated scheme for the warp measurement. We find an interesting color difference between S-and U-shaped warps. The U-type warp galaxies exhibits considerable color offset towards blue compared to both the S-type warps and the control sample of un-warped galaxies. The effect is even more pronounced for galaxies (a) with the greater warp amplitude and (b) with lower luminosity. This is the first piece of observational evidence that the S- and U-shaped warps are on different evolutionary phases in terms of not only dynamics but stellar populations as well. We discuss the implications in the context of the warp evolution theory.

• The Bulletin of The Korean Astronomical Society
• /
• v.44 no.1
• /
• pp.34.2-34.2
• /
• 2019

Several observational results show a tighter pitch angle at wavelengths of optical and near-infrared than those that are associated with star formation, which is in agreement with the prediction of the density wave theory. In my recent numerical studies, the dependence of the shock positions relative to the potential minima is due to the tendency that stronger shocks form farther downstream. This causes a systematic variation of the perpendicular Mach number, with radius and makes the pitch angle of the gaseous arms smaller than that of the stellar arms, which supports the prediction of the density-wave theory, independently. However, some observations still give controversial results which show similar pitch angles at wavelengths, and there is no statistical study comparing observations and numerical models directly. By analyzing optical image of disk galaxies in the Carnegie-Irvine Galaxy Survey (CGS), I measured the physical values of stellar and gaseous arms such as their strength, length, and pitch angles. For direct comparison with numerical results, I analyzed more than 30 additional numerical models with varying the initial parameters in model galaxies. In this talk, I will present results both of observational and numerical samples and discuss the physical properties of spiral structures based on the density-wave theory.

• Ocean and Polar Research
• /
• v.44 no.1
• /
• pp.69-82
• /
• 2022

The Ross Sea, Antarctica plays an important role in the formation of Antarctic Bottom Water (AABW) which is the densest water mass in global thermohaline circulation. Of the AABW, 25% is formed in the Ross Sea, and sea ice formation at the polynya (ice-free area) developed in front of ice shelves of the Ross Sea is considered as a pivotal mechanism for AABW production. For this reason, monitoring the Ross Sea variations is very important to understand changes of global thermohaline circulation influenced by climate change. In addition, the Ross Sea is also regarded as a natural laboratory in investigating ice-ocean interactions owing to the development of the polynya. In this article, I introduce characteristics of the Ross Sea described in previous observational studies, and investigate variations that have occurred in the Ross Sea in the past and those taking place in the present. Furthermore, based on these observational results, I outline variations or changes that can be anticipated in the Ross Sea in the future, and make an appeal to researchers regarding the importance and necessity of continuous observations in the Ross Sea.

• International Journal of Computer Science & Network Security
• /
• v.22 no.1
• /
• pp.21-26
• /
• 2022

This study touched on the effect of the different electronic course designs on the programming skills of university students. The researcher used the experimental research design of a quasi-experimental of two experimental groups to achieve the objectives of the study. The first group underwent an electronic course designed in the holistic pattern, and the second group was taught a course in a sequential pattern. This experimental design was intended to measure the impact of these two learning modes on the learners' cognitive and performance achievement of programming skills. An achievement test and observational form were the data collection tools. Data were analyzed statistically using Pearson correlation, Mann Whitney Test, and Alpha Cronbach. The findings revealed statistically- significant differences between the mean scores of the students of the first and second experimental groups in favor of the former concerning the observational form and the latter in the cognitive test. Based on the findings, some recommendations are suggested. Due to their effectiveness in the educational process, expanding using the e-courses at universities is vital. The university teachers are highly recommended to design e-courses and provide technical and material support to the e-courses user to fulfill their design purpose.

• Journal of Trauma and Injury
• /
• v.35 no.3
• /
• pp.151-158
• /
• 2022

Purpose: There is a strong correlation between trauma and pain. Pain increases the rate of depression, posttraumatic stress disorder, and even mortality in trauma patients. Methods: This institution-based, provider-blinded and patient-blinded, observational study was conducted among trauma patients treated at Tikur Anbessa Specialized Hospital. Over the course of 3 months, this study included patients who had no prior pain management at other hospitals before presentation, and who presented within 24 hours of the traumatic event. Results: Of the 74 patients evaluated, none of the patients had their pain level scored. The researcher-provided pain scale showed a severe subjective pain score for 79.7% of the patients and a severe functional activity score for 59.5% of the patients. Analgesia was provided at an average of 55.4 minutes after presentation and all patients received either diclofenac or tramadol. Satisfactory pain reduction after analgesia was 28.8% for patients initially complaining of severe pain, 54.6% for moderate pain, and 66.7% for mild pain, with the difference being statistically significant (P<0.05). Forty percent of patients discharged home received no analgesia after the first dose provided upon presentation. Conclusions: Pain scoring was nonexistent during the course of the study. The poor utilization rate of analgesia combination and opioids led to unsatisfactory pain outcomes in patients evaluated and followed for 24 hours after presentation.

• Journal of the Korean Society of Physical Medicine
• /
• v.17 no.1
• /
• pp.11-20
• /
• 2022

PURPOSE: A gait assessment is an important component of the rehabilitation process, and observational gait assessment (OGA) is used routinely in clinical settings. This study examined the association of OGA tools with the independent walking ability in stroke patients to determine a cutoff value of the OGA tool according to independence levels of stroke patient gait. METHODS: Two hundred ten hemiparetic stroke patients participated in the study. The independence of gait was identified using the Functional Ambulation Category (FAC) classifications. The walking ability was assessed using OGA tools (Rivermead Visual Gait Assessment [RVGA], Wisconsin Gait Scale [WGS], Tinetti Gait Scale [TGS], and Functional Gait Analysis [FGA]). RESULTS: Stepwise multiple regression analysis showed that among the OGA tools, the FGA correlated with the FAC. The FGA explained approximately 77% of the variance in FAC. In distinguishing the independence levels, the cutoff values were as follows: between FAC 1 and FAC 0 was .5 points; between FAC 2 and lower levels, 5.5; between FAC 3 and lower levels, 11.5; between FAC 4 and lower levels, 14.5; and between FAC 5 and lower levels, 18.5. Items 1, 2, 3, and 10 were identified as explaining most of the variance in the FGA in the stepwise multiple regression. CONCLUSION: The present study found that the FGA is an assessment tool related to the level of gait independence after stroke. Furthermore, the FGA total score can serve as an index of the increase in independence level after stroke.

• The Journal of Korean Medicine
• /
• v.43 no.2
• /
• pp.42-50
• /
• 2022

Objectives: The purpose of this study is to investigate the characteristics of female infertility patients who come to Korean medicine clinics and analyze the trends of Korean medicine treatment methods and the effects of female infertility by registry data. Methods: We are recruiting study participants from Korean medicine hospitals and clinics. If female infertility patients come, we will ask them to register for this study. After enrollment, we will collect demographic information, treatment methods, pregnancy results, adverse events, and treatment costs. Result: First, we will analyze the characteristics of patients, the status of the use of Korean medicine treatment interventions, the cost status of Korean medicine infertility treatment, and the delivery characteristics of pregnant women after Korean medicine treatment. Second, we will analyze the effectiveness of Korean medicine treatment. The primary outcome is clinical pregnancy rate, and secondary outcomes are 12-week pregnancy maintenance rate, degree of dysmenorrhea and premenstrual syndrome, stress level, and health-related quality of life score. Discussion: This study is the first observational multi-center study in Korea for female infertility. By establishing the registry, we are creating a resource that contains patient-reported outcome measures for female infertility. The registry is expected to provide valuable data for developing Korean medicine Clinical practice guidelines for female infertility.

• CELLMED
• /
• v.12 no.3
• /
• pp.10.1-10.12
• /
• 2022

Objective: The objective of the study was to evaluate the effect of Sharbat Afsantin in Polycystic Ovarian Disease. Methods: An open observational study was carried out in the Department of Ilmul Qabalat wa Amraze Niswan. Diagnosed cases(n=30) of PCOD were included in the study. Patients with thyroid dysfunction, systemic diseases, on hormonal treatment in last three months, pregnancy and lactation were excluded. Research drug (Sharbat Afsantin) was administered orally in a dose of 25ml twice daily for 15 days/cycle for three consecutive cycles. Outcome measures were, changes in subjective parameters (duration of cycle, duration and amount of flow and weight reduction) and objective parameters {pictorial blood loss assessment chart (PBAC) score, basal metabolic index (BMI), modified Ferriman Gallwey (mFG) score, acanthosis nigricans scale and pelvic ultrasonography}. Data were analyzed using paired Student 't' test. Results: Changes in duration of cycle, duration and amount of flow were achieved in 83.3%, 50% and 40% patients respectively and weight reduction in 30% patients. Changes in PBAC score and BMI were achieved in 50% and 30% patients respectively and 30% patients showed normal findings on pelvic ultrasonography. Conclusion: Sharbat Afsantin can be used as an alternate remedy in PCOD patients, as it has significant effect to regularize menstruation by reduction in BMI and probably by improving insulin resistance in PCOD. No adverse effect of Sharbat Afsantin was noted during the trial.

• Journal of Dental Anesthesia and Pain Medicine
• /
• v.23 no.2
• /
• pp.59-67
• /
• 2023

General anesthesia may influence the postoperative sleep cycle; however, no clinical studies have fully evaluated whether anesthesia causes sleep disturbances during the postoperative period. In this scoping review, we explored the changes in postoperative sleep cycles during surgical procedures or dental treatment under general anesthesia. We compared and evaluated the influence of general anesthesia on sleep cycles and sleep disturbances during the postoperative period in adult and pediatric patients undergoing surgery and/or dental treatment. Literature was retrieved by searching eight public databases. Randomized clinical trials, observational studies, observational case-control studies, and cohort studies were included. Primary outcomes included the incidence of sleep, circadian cycle alterations, and/or sleep disturbances. The search strategy yielded six studies after duplicates were removed. Finally, six clinical trials with 1,044 patients were included. In conclusion, general anesthesia may cause sleep disturbances based on alterations in sleep or the circadian cycle in the postoperative period in patients scheduled for elective surgery.