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The recent emerging significance of the Internet of Things (IoT) demands sensor devices to be integrated with many different functional structures and devices while conserving their original functionalities. To this end, optical transparency and mechanical flexibility of sensor devices are critical requirements for optimal integration as well as high sensitivity. In this work, a transparent, flexible, and sensitive gas sensor building platform is introduced by using multilevel self-assembly of block copolymers (BCPs) and polystyrene (PS) colloids. For the demonstration of an H

Increasing the complexity of nanomaterials in terms of their structure and chemical composition has attracted significant attention, because it can yield unique scientific outcomes and considerable improvements for practical applications. Various approaches are being developed for the synthesis of nanostructured composites. Coordination polymers (CPs) emerged as new precursors in solid-state reactions for nanomaterials nearly two decades ago; the repetitively arranged inorganic and organic units can facilitate the production of nanoscale particles and porous carbon upon thermal decomposition. Metal-organic frameworks (MOFs), a subgroup of CPs featuring crystalline and porous structures, have subsequently become primary objects of interest in this field, as can be seen by the rapidly increasing number of reports on this topic. However, unique composite materials with increasingly complex nanostructures, which cannot be achieved via conventional methods, have been rarely realised, even though conventional MOF research has enabled the delicate control of structures at the molecular level and extensive applications as templates. In this regard, a comprehensive review of the fabrication strategies of MOF-based precursors and the thermal transformation into functional nanomaterials is provided herein, with a particular emphasis on the recent developments in nanocomposite research. We briefly introduce the roles and capabilities of MOFs in the synthesis of nanomaterials and subsequently discuss diverse synthetic routes for obtaining morphologically or compositionally advanced composite nanomaterials, based on our understanding of the MOF conversion mechanism.

This article deals with a one-searcher multi-target search problem where targetswith different detection priorities move in Markov processes in each discrete time interval over agiven space search area, and the total number of search time intervals is fixed. A limitedsearch resource is available in each search time interval and an exponential detection functionis assumed. The searcher can obtain a target detection reward, if the target is detected, whichrepresents the detection priority of target and does not increase with respect to time. The objective is toestablish the optimal search plan that allocates the search resource effort over the search areasin each time interval in order to maximize the total detection reward. The analysis shows that the given problem can be decomposed into interval-wise individualsearch problems, each being treated as a single stationary target problem for each timeinterval. Thus, an iterative procedure is derived to solve a sequence of stationary targetproblems. The computational results show that the proposed algorithm guaranteesoptimality.

We aimed to determine whether vitamin D levels before prostate biopsy have diagnostic value for clinically significant prostate cancer. The study cohort included patients who underwent prostate biopsy. A total of 224 patients were enrolled in our study, and serum vitamin D levels were measured from February 2016 to December 2019 in routine laboratory tests. To determine the relationship between vitamin D levels and the aggressiveness of prostate cancer, we used multivariate analysis. Based on the histopathological results, the serum vitamin D level was marginally lower in the group with higher positive cores and pT3 or higher, and the serum vitamin D level was significantly lower in the large tumor volume group. In the univariate analysis, the prostate cancer diagnosis rate was associated with low vitamin D levels. In clinically significant prostate cancer diagnosis, low vitamin D levels were found in the univariate (odds ratio [OR], 0.955; P

In this paper, a modified finite-difference time-domain (FDTD) method is proposed for the rapid analysis of a Hertzian dipole source in the low-frequency band. The FDTD technique is one of the most widely used methods for interpreting high-resolution problems such as those associated with the human body. However, this method has been difficult to use in the low-frequency band as the required number of iterations has increased significantly in such cases. To avoid this problem, FDTD techniques using quasi-static assumptions in low-frequency bands were used. However, this method was applied only to plane wave excitation, making it difficult to apply to near-field problems. Therefore, a modified approach is proposed, involving the application of the FDTD technique with a quasi-static approximation to an electric and magnetic dipole problem. The results when using the proposed method are in good agreement with those from a theoretical solution. An example of comparison with the standard FDTD method is shown for illustrating the proposed method’s performance.

Preoperative renal function is associated with worse outcomes in patients undergoing radical nephroureterectomy (RNU). The purpose of this systemic review and meta-analysis was to determine the association of preoperative renal function with oncological outcome in patients who underwent RNU. We searched articles published up to March 2021 in PubMed, Scopus, and Embase by combining “urothelial carcinoma”, “radical nephroureterectomy”, and “estimated glomerular filtration rate”. We also manually screened the reference list for publications following general guidelines recommended by the preferred reporting items for systematic reviews and meta-analyses (PRISMA) statement. The relationship between preoperative renal function and survival was expressed as overall survival (OS), progression-free survival (PFS), and cancer-specific survival (CSS). This review and meta-analysis included 13 studies involving a total of 4668 patients who received RNU. Pooled analysis showed significant negative association of preoperative renal function with PFS (HR: 1.51, 95% CI: 1.23–1.80, p < 0.00001), CSS (HR: 1.63, 95% CI: 1.38–1.92, p < 0.00001), and OS (HR: 1.22, 95% CI: 1.10–1.35, p < 0.00001). Patients with upper tract urothelial carcinoma (UTUC) who received RNU showed a significant negative association of preoperative renal function with survival.

Long-term exposure to childhood abuse and occurrence of mental illness are positively correlated. Using long-term tracking data in Korea, we identified the characteristics of children and adolescents who experienced abuse and impact thereof on their psychopathology. Using the Korea Welfare Panel data, 354 teenagers in grades 4–6 of elementary school participated, were assessed at baseline, and monitored 3 years later. They were categorized into Never, Occurrence, Continuation, and Discontinuation groups according to changes in the abuse experienced. Psychopathology was evaluated using K-CBCL. Childhood abuse experience significantly affected psychopathology. At the baseline, the Continuation and Discontinuation groups had a higher severity of psychopathology than the Never group. Psychopathology at the baseline was associated with whether the patient experienced abuse that year. In the follow-up observation, the risk of psychopathology in the Occurrence and Continuation groups was higher than that in the Never group. The Discontinuation group had decreased psychopathology, which was not clinically significant in the follow-up observation (INT aRR = 2.09, 95% CI 0.61–7.13, EXT aRR = 4.23, 95% CI 1.12–16.07). Stopping abuse in late childhood reduces adolescents’ psychopathology in the long term, meaning they can recover their normal developmental trajectory according to risk groups and provide effective interventions including discontinuation of abuse.

Objective This study aimed to clarify the role of acute alcohol use and alcohol use disorder in individuals exhibiting suicidal behaviors, including repetition of suicide attempt. Methods Data pertaining to 691 suicide attempters who had visited an emergency center and had been followed-up from 2010 to 2015 were gathered. Participants were categorized into following three groups according to alcohol use pattern at the time of the suicide attempt: 1) suicide attempters with neither alcohol use disorder nor acute alcohol consumption (NAU), 2) suicide attempters who had used alcohol during the suicide attempt but did not have alcohol use disorder (AAU), and 3) suicide attempters with alcohol use disorder (AUD). Group comparisons and multivariate Cox proportional models for suicidal behavior were used for statistical analysis. Results AUD have been shown to have lower lethality of suicide attempt but higher risk of suicide reattempts in the future. Furthermore, positive relationships between suicide reattempts and AUD persisted throughout the longer period than other groups. Conclusion Suicide attempters with AUD should be considered a high-risk group for suicide reattempts in future, and this group should be followed-up for a longer period with specialized care program.

Background Despite heterogeneity of older people in suicidal behavior, research identifying characteristics by age groups is scarce. We examined baseline features of older community-dwelling suicidal ideators by dichotomized age groups and the 6-month trajectory of their suicidal ideation along with its related psychopathology. Predictors of suicidal ideation within each group were investigated. Methods Older community-dwelling suicidal ideators enrolled in the Korean Cohort for the Model Predicting a Suicide and Suicide-related Behavior study were subdivided into the “young-old (65–74 years)” and “old-old (≥75 years)” group. Baseline, 1-, and 6-month assessments were compared. Within each group, multiple regression analysis using rating scales (Patient Health Questionnaire-9, Beck Anxiety Inventory, Alcohol Use Disorders Identification Test, Stress Questionnaire for Korean National Health and Nutrition Examination Survey-Short Form, and Social Relationships Scale) was conducted to identify predictors of suicidal ideation measured with the intensity subscale of the Columbia-Suicide Severity Rating Scale. Two-way repeated-measures analysis of variance (RM-ANOVA) was used to compare changes in suicidal ideation, depression, anxiety between age groups over time, and one-way RM-ANOVA to examine changes within each age group. Results Among 29 “young-old” and 53 “old-old” ideators, the latter were less likely to be receiving psychiatric treatment (odds ratio [OR] = 4.065) and make suicide attempts (OR = 2.874), whereas the former revealed greater levels of anxiety and stress. Baseline depression and stress in the “young-old” group and the “old-old” group, respectively, predicted the intensity of suicidal ideation at both baseline and 1-month assessments. No significant age group x time interactions on suicidal ideation and depression were found. However, within each age group, both suicidal ideation and depression significantly decreased only during the first month with no further improvement. Conclusion We speculate cautiously that more attention may need to be paid to the “old-old” ideators in the evaluation of psychiatric issues and for referral to psychiatrists. To decrease suicidal ideation, tailored approaches involving proactive, timely management of depression in the “young-old” and interventions focusing on stress reduction in the “old-old,” would be helpful.

Background: The Korean Cohort for the Model Predicting a Suicide and Suicide-related Behavior (K-COMPASS) study is a prospective, naturalistic, observational cohort study, aiming to identify predictors of suicide attempt and suicide characteristics in the Korean suicidal population. The findings intend to contribute to a thorough understanding of suicidal phenomena and development of suicide prevention guidelines. The present cross-section study examines the study rationale, methodology, and baseline characteristics of the participants. Methods: Participants were enrolled via the hospital and community gateways, establishing the hospital-based cohort (HC) and community-based cohort (CC), respectively. Baseline assessment was conducted on sociodemographic, clinical, diagnostic, and psychopathological aspects. The Columbia-Suicide Severity Rating Scale was used to investigate suicidality. Results: A total of 800 suicidal people aged 15 years or older were enrolled from 8 university hospitals and 8 community mental health welfare centers (CMHWCs), among whom 480 (60%) were suicidal ideators and 320 (40%) were attempters. The ideators comprised 207 CC and 273 HC participants, whereas the attempters, 34 CC and 286 HC participants. Despite their lower severity in some measures, including suicidal ideation, compared with their HC counterparts, the CC participants within each group of ideators or attempters presented clinically significant psychopathology. Moreover, alcohol use problems and past suicide attempt were more likely to be found in CC participants. Only 11.1% to 21.6% of the participants in each of the four groups (defined by the cohorts and the ideators/attempters) were on any type of psychiatric treatment. Conclusions: Suicidal visitors to CMHWCs need to be as closely monitored as suicidal patients in university hospitals, especially considering their association with problem drinking and past suicide attempt. A cautious assumption is that the high suicide rate in Korea might be partly attributable to the low proportion of patients receiving psychiatric services. Keywords: Suicide, Suicide attempt, Cohort studies, Hospitals, Community mental health centers, Korea

Background Evidence continues to accumulate that the presence or absence of early trauma (ET) implies unique characteristics in the relationships between suicidal ideation and its risk factors. We examined the relationships among recent stress, depressive symptoms, anxiety symptoms, and suicidal ideation in Korean suicidal women with or without such a history. Methods Using data on suicidal adult females, 217 victims and 134 non-victims of ET, from the Korean Cohort for the Model Predicting a Suicide and Suicide-related Behavior, we performed structural equation modeling to investigate the contribution of recent stress, depressive symptoms, and anxiety symptoms on suicidal ideation within each group according to the presence or absence of a history of ET. Results Structural equation modeling with anxiety and depressive symptoms as potential mediators showed a good fit. Recent stress had a direct effect on both depressive symptoms and anxiety symptoms in both groups. Only anxiety symptoms for victims of ET (standardized regression weight, 0.281; P = 0.005) and depressive symptoms for non-victims of ET (standardized regression weight, 0.326; P = 0.003) were full mediators that increased suicidal ideation. Thus, stress contributed to suicidal ideation by increasing the level of anxiety and depressive symptoms for victims and non-victims, respectively. Conclusion Tailored strategies to reduce suicidal ideation should be implemented according to group type, victims or non-victims of ET. Beyond educating suicidal women in stress-management techniques, it would be effective to decrease anxiety symptoms for those with a history of ET and decrease depressive symptoms for those without such a history., Graphical Abstract

Background Youth suicide attempts are a major risk factor for future complete suicides. However, the characteristics of suicide attempters based on the emergency department (ED) have rarely been explored, making it challenging to comprehend the characteristics of youth suicide attempters comprehensively. This study aims to investigate the characteristics of youth suicide attempters who visited the ED. Methods We examined the youth (age: 12–25 years) and adult (age: 26–65 years) groups of suicide attempters who visited the ED in Wonju-si, Gangwon-do, Korea. Interviews were conducted with attempters and guardians to identify sociodemographic, clinical, and suicide-related variables. Besides, we performed bivariate logistic regression analysis with statistically adjusted gender, educational age, Socioeconomic Status(SES) level, and medical illness. Results Youth were diagnosed more frequently with Personality disorder compared to adults. Besides, youth tended to report interpersonal or abuse as motivations for suicide, whereas adults tended to report medical illness or economic problems. Furthermore, youth attempted suicide more impulsively and repeatedly; however, medical lethality of each attempt tended to be lower than adults. Limitation We experienced difficulty in collecting complete information because of poor consciousness or cooperation of patients who visited the ED immediately after suicide attempt. Also, the study cohort was only recruited from one hospital in a region. Conclusion Youth suicide attempters are suggested to have relatively serious and persistent problems involving personality or traits than adults. Thus, this study highlights the significance of preventive strategies based on early psychopathological evaluation and treatment.

Few studies have compared the three suicidality groups-suicidal ideators (SIs), single suicide attempters (SSAs), and multiple suicide attempters (MSAs)-in relation to the suicidal process. This cross-sectional study investigated trends and differences in suicide risk factors across suicidality groups. Using the baseline data of the Korean Cohort for the Model Predicting a Suicide and Suicide-related Behavior, we analyzed trends (Jonckheere-Terpstra or Mantel-Haenszel χ2 test) and differences (analysis of covariance or logistic regression) in sociodemographic and clinical factors, psychiatric diagnoses, as well as clinical rating scores on psychopathology (suicidal ideation, depressive symptoms, anxiety symptoms, and problem drinking), trait impulsiveness, and stress across suicidality groups. Across suicidality groups comprising 193 SIs, 207 SSAs, and 376 MSAs, we observed a decreasing trend in age and increasing trends in history of early trauma, familial histories of suicide attempts and suicide, most diagnoses and psychopathologies (suicidal ideation, anxiety symptoms, and problem drinking), trait impulsiveness, and stress-with MSAs more likely to have histories of early trauma and familial suicide, almost uniformly higher proportions of diagnoses, and higher psychopathology rating scores. Overall, increasing trends in suicide risk factors were found across all suicidality groups. Notably, MSAs presented greater proportions of most psychiatric diagnoses and higher degrees of most psychopathologies, motor impulsiveness, and stress, indicating they were at more severe clinical states and were closer to suicide. Mental health professionals should ascertain the number of suicide attempts to identify MSAs, implement more thorough evaluations, and employ additional measures for reducing motor impulsiveness.

The purpose of this study was to investigate the effect of continuous case management with a flexible approach on the prevention of suicide by suicide reattempt in a real clinical setting. The subjects in this study were 526 suicide attempters who visited emergency rooms in a teaching hospital in South Korea. Subjects were provided a continuous case management program with a flexible approach according to the severity of their suicide risk and needs. During the entire observation period (from 182 days to 855 days, mean = 572 &plusmn, 254), 18 patients (3.7%) died by suicide reattempt: Eight patients (2.27%) in the case management group and 10 patients (7.35%) in the no-case management group. The Cox regression analysis showed that the case management group had a 75% lower risk of death from suicide attempts than the no-case management group (HR = 0.34, 95% CI = 0.13&ndash, 0.87). This result was shown to be more robust after adjusting for confounding factors such as gender, age, psychiatric treatment, suicide attempts, and family history of suicide (adjusted HR = 0.27, 95% CI = 0.09&ndash, 0.83). This study was conducted in a single teaching hospital and not a randomized controlled one. A flexible and continuous case management program for suicide attempters is effective for preventing death by suicide reattempts.

The aim of this study was to evaluate the association between content type of smartphone use and psychological characteristics and addiction propensity, including the average time of smartphone use and problematic smartphone use. Data were obtained from the 2017 Korea Youth Risk Behavior Web-Based Survey, a nationally representative survey of middle- and high-school students (n = 62,276). The content type of smartphone use was divided into four categories: (1) Study, (2) Social-Networking Services (SNS), (3) Game, and (4) Entertainment. The association of depressive mood and suicidal ideation with content type of smartphone use was analyzed, using multiple and binary logistic regression analyses, respectively. The relationship between content type of smartphone use and time spent on smartphone use and problematic smartphone use was analyzed by using multiple logistic regression, adjusted for related covariables. The results of this study revealed that depressive mood and suicidal ideation were significantly associated with the SNS smartphone use group, compared with the other groups. Our results also indicate that the SNS group showed higher addiction propensity, such as overuse and experiencing adverse consequences of smartphone use.

Background: In the present study, we investigated the association between substance use by adolescents and parental smoking status based on data from the 2016 Korean Youth Risk Behavior Web-based Survey, a national school-based survey. Methods: Data from a nationally representative sample of Korean adolescents aged 12–18 years (n = 65,528) were analyzed, and the risk of substance use according to the parental smoking status was investigated. Results: We found that smoking by both parents was a greater risk factor for substance use by adolescents than smoking by any one parent. Moreover, maternal smoking was a greater risk for substance use by adolescents than paternal smoking. We also investigated sex differences in the risk of substance use as a result of the parental smoking status. The differences in the substance use status according to the sex of both parents and children were also identified after adjustment for second-hand smoking. Conclusions: Accurate evaluation of the family smoking environment and whole-family interventions are necessary for preventing and intervening in substance use by adolescents.

In this cross-sectional study, we aimed to identify distinguishing factors between populations with suicidal ideation recruited from hospitals and communities to make an efficient allocation of limited anti-suicidal resources according to group differences. We analyzed the baseline data from 120 individuals in a community-based cohort (CC) and 137 individuals in a hospital-based cohort (HC) with suicidal ideation obtained from the Korean Cohort for the Model Predicting a Suicide and Suicide-related Behavior (K-COMPASS) study. First, their sociodemographic factors, histories of medical and psychiatric illnesses, and suicidal behaviors were compared. Second, diagnosis by the Korean version of the Mini International Neuropsychiatric Interview, scores of psychometric scales were used to assess differences in clinical severity between the groups. The results revealed that the HC had more severe clinical features: more psychiatric diagnosis including current and recurrent major depressive episodes (odds ratio [OR], 4.054; P < 0.001 and OR, 11.432; P < 0.001, respectively), current suicide risk (OR, 4.817; P < 0.001), past manic episodes (OR, 9.500; P < 0.001), past hypomanic episodes (OR, 4.108; P = 0.008), current alcohol abuse (OR, 3.566; P = 0.020), and current mood disorder with psychotic features (OR, 20.342; P < 0.001) besides significantly higher scores in depression, anxiety, alcohol problems, impulsivity, and stress. By comparison, old age, single households, and low socioeconomic status were significantly associated with the CC. These findings indicate the necessity of more clinically oriented support for hospital visitors and more socioeconomic aid for community-dwellers with suicidality., Graphical Abstract

Background Many suicide attempters brought to our emergency department (ED) have been found to have alcohol problems, and this should be taken serious consideration because alcohol use disorder is a risk factor for suicide reattempt. In this study, we aimed to estimate the effectiveness of alcohol-related biochemical markers and Alcohol Use Disorder Identification Test Consumption (AUDIT-C) in suicide attempters who visited our ED based on the gold standard for clinical diagnosis used by psychiatrists for alcohol use disorder. Moreover, we aimed to search for a significant standard when clinicians make correct predictions about alcohol use disorder using these markers. Methods Among the subjects who visited ED following a suicide attempt, a total of 203 subjects were selected. Following a psychiatric interview, the subjects who met the criteria for alcohol abuse or alcohol dependence according to DSM-IV-TR in the past year were defined as the “alcohol use disorder” group. Although some subjects did not meet these criteria, men with a weekly alcohol intake of ≥14 drinks and women with a weekly alcohol intake of ≥7 drinks were classified as the “risky drinking” group. AUDIT-C was used as a self-report; further, aspartate aminotransferase, gamma-glutamyltransferase (GGT), and carbohydrate-deficient transferrin (CDT) were assayed using standard methods, and GGT–CDT was calculated using this formula: 0.8 × ln(GGT) + 1.3 × ln(%CDT). Results In total, 88 subjects met the criteria for alcohol use disorder and 115 were included in the reference group. In the screening for alcohol use disorder, the AUC of AUDIT-C was 0.89 for men and 0.87 for women. In the screening for risky drinking, the AUC of AUDIT-C was 0.99 for men and 0.93 for women. Compared with other biochemical markers, AUDIT-C showed the highest AUC value for screening for both alcohol use disorder and risky drinking, with the trend being more prominent in men. Conclusions Among the biochemical markers, AUDIT-C yielded the highest sensitivity, specificity, and accuracy in diagnosing alcohol use disorder among suicide attempters in ED. Comparison of results revealed that the use of AUDIT-C with biochemical markers or its use alone can help screen for alcohol use disorder or risky drinking in clinical settings.

Background The purpose of this study was to identify the demographic and clinical characteristics of suicide attempts in adolescents who visit the emergency department compared to those of adults. Methods This study included 149 children under the age of 18, and 1427 people in the age of 19–65 who came to the emergency department with suicide attempt from 2009 to 2015. We compare sociodemographic, clinical, and suicide attempt-related characteristics through Chi-square test and logistic regression analysis to evaluate the difference between two groups. Results In adolescents, suicide attempters had more number of previous suicide attempt history than adults. Adolescents used more non-lethal method such as poisoning of over the counter drugs and had about 5 times higher odds ratio in suicide attempts with analgesics. The motivation of suicide attempt among adolescents was more related with interpersonal problems but less with financial or illness-related problems. The intention of suicide attempt in adolescents was less serious and lethal compared to adults. Conclusion Suicide attempts among adolescents had showed different from adults in method, motivation and intention. Considering the characteristics of suicide attempt among adolescent, it is necessary to keep close attention to adolescent’s suicide attempters and develop the customized intervention program to prevent the suicide attempt in this groups.

(1) Background: The health implications associated with the metabolically healthy obese (MHO) phenotype, in particular related to symptoms of depression, are still not clear. the purpose of this study is to check whether depression and metabolic status are relevant by classifying them into four groups in accordance with the MHO diagnostic standard. Other impressions seen were the differences between sexes and the effects of the MHO on the occurrence of depression. (2) Methods: A sample of 3,586,492 adult individuals from the National Health Insurance Database of Korea was classified into four categories by their metabolic status and body mass index: (1) metabolically healthy non-obese (MHN), (2) metabolically healthy obese (MHO), (3) metabolically unhealthy non-obese (MUN), and (4) metabolically unhealthy obese (MUO). Participants were followed for six to eight years for new incidences of depression. The statistical significance of the general characteristics of the four groups, as well as the mean differences in metabolic syndrome risk factors, was assessed with the use of a one-way analysis of variance (ANOVA). (3) Results: The MHN ratio in women was higher than in men (men 39.3%, women 55.2%). In both men and women, depression incidence was the highest among MUO participants (odds ratio (OR) = 1.01 in men, OR = 1.09 in women). It was concluded as well that, among the risk factors of metabolic syndrome, waist circumference was the most related to depression. Among the four groups, the MUO phenotype was the most related to depression. Furthermore, in women participants, MHO is also related to a higher risk of depressive symptoms. These findings indicate that MHO is not a totally benign condition in relation to depression in women. (4) Conclusion: Therefore, reducing metabolic syndrome and obesity patients in Korea will likely reduce the incidence of depression.

In this paper, an effective numerical analysis method is proposed for calculating dosimetry of the wireless power transfer system operating low-frequency ranges. The finite-difference time-domain (FDTD) method is widely used to analyze bio-electromagnetic field problems, which require high resolution, such as a heterogeneous whole-body voxel human model. However, applying the standard method in the low-frequency band incurs an inordinate number of time steps. We overcome this problem by proposing a modified finite-difference time-domain method which utilizes a quasi-static approximation with the surface equivalence theorem. The analysis results of the simple model by using proposed method are in good agreement with those from a commercial electromagnetic simulator. A simulation of the induced electric fields in a human head voxel model exposed to a wireless power transmission system provides a realistic example of an application of the proposed method. The simulation results of the realistic human model with the proposed method are verified by comparing it with the conventional FDTD method.