• Title/Summary/Keyword: Human head model

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Electromagnetic Interactions between a Cellular Phone and the Human Body and Synthesis of a Bone-Equivalent Material (휴대폰 전자파와 인체의 상호 영향 및 뼈 유사 물질 합성 연구)

  • 윤용섭;김인광;전중창;박위상
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.10 no.2
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    • pp.277-290
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    • 1999
  • A simulation using the finite-difference time-domain method to analyze the electromagnetic interactions between a cellular phone and the human body was conducted, and a synthesis of a bone-equivalent material to make a human head phantom was performed. A test model of the cellular phone was fabricated to measure its reflection coefficient and radiation pattern in the free space. Various effects of the human body on the characteristics of the phone, such as input impedance, reflection coefficient, radiation pattern, and radiation efficiency are analyzed as the distance between the head and the phone antenna varies. When the phone was operated close to the head, the resonant frequency of the antenna decreased by up to 12%. With the output power of 0.6W, as long as the distance was larger than 30mm, the 1-g averaged peak SAR was below the ANSI/IEEE safety guideline, 1.6 W/kg. To synthesize the bone-equivalent material, an epoxy with hardener and a graphite powder were used as basis ingredients, and a small amount of a conducting epoxy was added to control the conductivity of the material. A material having a relative permittivity of 18.04 and a conductivity of 0.347, which are close to those of the bone at 850 MHz, was synthesized.

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Analysis and Design of Whole-Head Magnetic Brain Stimulators: A Simulation Study

  • Lee, Chany;Im, Chang-Hwan;Jung, Hyun-Kyo
    • International Journal of Control, Automation, and Systems
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    • v.5 no.3
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    • pp.337-342
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    • 2007
  • This paper proposes a helmet-type whole-head brain stimulator system considering a realistic head geometry. For more accurate design and computer simulations, a realistic volume conductor model was adopted and the current evoked on human cerebral cortex was analyzed using the boundary element method (BEM). To obtain a more focalized evoked current around the target points, various coil configurations were tested and an average targeting error of about 10 mm was obtained.

A spatial housing domand analysis with the use of residential choice probabilities (주거지 선택확률을 이용한 지역적 주택수요의 분석)

  • SooKyeongHo
    • Proceeding of Spring/Autumn Annual Conference of KHA
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    • 1992.11a
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    • pp.45-51
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    • 1992
  • The purpose of this study was to predict the spatial housing demand of households in Seoul with the use of residential choice probabilitics. An multinomial legit model is developed using socio-demographic and housing characteristics. SAS package was utilized to estimate this model. This study used the data obtained by the Korea Rosearch Institute for Human Settlemente in 1989. The sample size was 3941 households in Seoul.The residential choice probability varicd depending upon the residential area, head age, head age, tenure and work place. The households with students were more likely to choose kangnam are. The households without young children had higher probability to choose new town near Seoul. Prime reason of this two results were considered the chi Id education and their better housing, Kangnam area was known to be the first consideration for residential choice regardless of work place. Low level of choice probability of kangman area for future residences however, was evidenced. Prime reason of such seemingly contradicting phenomenon is suspected for higher housing prices and limited affordability of people surveyed.

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Determinants of the Demand for Cash-Value Life Insurance (저축성 보험 보유 및 보유액에 영향을 미치는 요인 분석)

  • Baek Eun-Young;Joung Soon-Hee
    • Journal of Families and Better Life
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    • v.23 no.3 s.75
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    • pp.217-230
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    • 2005
  • The purpose of this study was to examine factors related to the purchase of cash-value life insurance of households. Based on human capital and bequest motive theories of the demand for life insurance, this study developed a conceptual model of the demand for life insurance of households. In addition, in order to capture the beneficiaries' preference and expected lifetime utility, expected future financial needs were included in the conceptual model. Using Heckit analysis, the model was estimated by two stages. The results supported that human capital, bequest motives and expected future financial needs were significant factors on both decision to have insurance and the mont of insurance. Specifically, if the household's head expected to have a higher potential in the future, the household was more likely to have insurance. If a household had dependents, the household was more likely to have insurance. As income or monthly expenditure increased, the probability of haying insurance and the amount of the insurance increased However, savings or social insurance were positively related to the purchase of insurance.

Numerical Method for Exposure Assessment of Wireless Power Transmission under Low-Frequency Band

  • Kim, Minhyuk;Park, SangWook;Jung, Hyun-Kyo
    • Journal of Magnetics
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    • v.21 no.3
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    • pp.442-449
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    • 2016
  • 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.

Analysis of the Work of the Head Nurse and a Work Model for the Head Nurse in University Hospitals in Korea (대학종합병원 수간호사의 업무분석과 모형연구)

  • 김인숙
    • Journal of Korean Academy of Nursing
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    • v.19 no.2
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    • pp.212-222
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    • 1989
  • When the head nurse who is pivotal in the nursing service administration of the hospital performs efficiently as a first-line manager, the effectiveness of the nursing unit, which includes the quality of nursing care, the jab satisfaction of staff members, and the cohesiveness of staff members is increased. With this point of view in mind, the researcher carried out a study to determine the actual work (the content of the work, the work process, the role of the head nurse, the activity media, and the purpose of the work) of the head nurse in a university hospital in Korea. In addition, this study was also carried out for the purpose of preparing an ideal model for the work of the head nurse. The research subjects were 39 head nurses. This included all the head nurses in two university hospitals except those who were working in outpatient care, operating rooms, central supply, nursing administration, in-service education and emergency care. Data were collected from September 24th to October 21th, 1987 and April 4th to 12th, 1988. A work activity record on which the head nurse recorded directly in a chronological narrative form, was used as the research instrument. The 234 work activity records, 39 head nurse's continuous recording over 6 days(from Monday to Saturday) were collected and analysed. The results were as follows ; 1. With regard to the work content for the total daily work of the head nurse, 45.2% of the activities were managerial activities but 58.1% of the head nurse' s time was spent in direct patient care. 2. With regard to the work process of the head nurse, specifically the location, the size and membership of groups contacted, the results were as follows : 1) Of the total daily work activities 92.4% were carried out in the nursing unit and this occupied 84.5% of total daily work time. Direct patient care was generally performed on the nursing unit and managerial work was performed in other areas. 2) Of the total daily work activities, 73% was with one or more persons and 51.2% of total daily work time was spent in groups. 3) A total of 51 persons, working in different capacities were contacted. These included 21 persons giving patient care, 19 persons working in nursing unit management, and 7 persons working in human resource management. 3. With regard to the head nurse's role in work activity, 53.3% of total daily work activities involved the informational role, 26.9%, the interpersonal role and 19.9%, the decisional role. With regard to time, 57.7% was spent in the informational role, 23.9%, in the interpersonal role and 18.3%, in the decisional role. When the head nurse performed managerial work, she gave nearly equal emphasis to all three roles when she gave direct patient care the informational role was increased. 4. With regard to the activity media, the number of unscheduled activities accounted for 27.1% of the activities, scheduled activities, 24.3%, desk work activity, 22.1%, rounds, 12.5% and telephone calls, made or received, 14.0%. In daily total work time managerial work related to desk work and scheduled activities were high, ranging from 29.8% to 29.9% but for direct patient care time, scheduled activities and unscheduled activities were high, ranging from 23.6% to 35.3%. 5. With regard to the purpose of the work performed, 54.4% of the total daily work was concerned with the team and 41.4% was concerned with the agency. The managerial work was concerned mainly with the team and the direct patient care was concerned mainly with the patient. When the frequency of an activity and time were compared no significant difference was found between the days for which the work was recorded for any of the variables : the work content, the work process, the work role, the activity media and purpose of the work. On the basis of this study the following are proposed as an ideal model for head nurse work in Korea : The managerial work should be increased to 70%. The decisional role activities should be increased to 40%. Twenty percent of the work activity should be allocated to agency, community and profession. It is believed that this model for the head nurse's work can contribute to guidelines for job description development. Finally, educational programs, organizational and structural devices, and administrative support are needed for the proper function of the head nurse in this proposed model.

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Observation Practice Using a Human Body Model in Medical Terminology Class (의학용어 수업에서 인체 모형을 이용한 관찰 실습)

  • Hyun-Woo Jeong;Hojun Yeom;Sangsoo Park
    • The Journal of the Convergence on Culture Technology
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    • v.10 no.2
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    • pp.35-42
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    • 2024
  • Biomedical engineering is a discipline that diagnoses and treats human diseases using engineering techniques based on medical and biological understanding. Proper biomedical engineering education requires education on medical terminology, human anatomy, and human physiology, but students have a preconceived notion that these basic medical subjects are subjects to be memorized. In order to eliminate these students' preconceptions, various educational methods must be developed so that students can easily access basic medical subjects. In this paper, we present a method to increase learning effectiveness by introducing observation practice of a human anatomical model to the medical terminology subject. The half-body model of the human body is a form in which various organs are assembled and can be observed by disassembling them one by one. This observation exercise consisted of questions about the organs of the head, neck, chest, and abdomen, with students working in groups to find answers. After the practice, students evaluated that this practice motivated them to learn and made it easier to understand the lecture.

A Classification Model for Predicting the Injured Body Part in Construction Accidents in Korea

  • Lim, Jiseon;Cho, Sungjin;Kang, Sanghyeok
    • International conference on construction engineering and project management
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    • 2022.06a
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    • pp.230-237
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    • 2022
  • It is difficult to predict industrial accidents in the construction industry because many accident factors, such as human-related factors and environment-related factors, affect the accidents. Many studies have analyzed the severity of injuries and types of accidents; however, there were few studies on the prediction of injured body parts. This study aims to develop a classification model to predict the part of the injured body based on accident-related factors. Construction accident cases from June 2018 to July 2021 provided by the Korea Construction Safety Management Integrated Information were collected through web crawling and then preprocessed. A naïve Bayes classifier, one of the supervised learning algorithms, was employed to construct a classification model of the injured body part, which has four categories: 1) torso, 2) upper extremity, 3) head, and 4) lower extremity. The predictor variables are accident type, type of work, facility type, injury source, and activity type. As a result, the average accuracy for each injured body part was 50.4%. The accuracy of the upper extremity and lower extremity was relatively higher than the cases of the torso and head. Unlike the other classifications, such as spam mail filtering, a naïve Bayes classifier does not provide a good classification performance in construction accidents. The reasons are discussed in the study. Based on the results of this study, more detailed guidelines for construction safety management can be provided, which help establish safety measures at the construction site.

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Lens system design for head mounted display using schematic eyes (정밀모형안을 이용한 Head Mounted Display용 렌즈계 설계)

  • 박성찬;안현경
    • Korean Journal of Optics and Photonics
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    • v.14 no.3
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    • pp.236-243
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    • 2003
  • We discussed the design of lens module schematic eyes equivalent to finite model eyes, which are used to model the human eye based on spherical aberration and Stiles-Crowford effect. The optical system for head mounted display (HMD) is designed and evaluated using lens module schematic eyes. In addition to a compact HMD system, an optical system with high Performance is required. To satisfy these requirements, we used diffractive optical elements and aspheric surfaces so that the color and mono-chromatic aberrations were corrected. The optical system for HMD is composed of 0.47 inch micro-display of SVGA grade with 480,000 pixels, a plastic hybrid lens for the virtual image, and the lens module schematic eyes. The designed optical system fulfills the current specifications of HMD: such as, EFL of 31.25 mm, FOV of 24H$\times$18V$\times$30D degrees, and overall length of 59.1 mm. As a result, we could design an optical system useful for HMD; the system is expected to be comfortable while the user wears it.

Artificial neural network controller for automatic ship berthing using head-up coordinate system

  • Im, Nam-Kyun;Nguyen, Van-Suong
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.10 no.3
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    • pp.235-249
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    • 2018
  • The Artificial Neural Network (ANN) model has been known as one of the most effective theories for automatic ship berthing, as it has learning ability and mimics the actions of the human brain when performing the stages of ship berthing. However, existing ANN controllers can only bring a ship into a berth in a certain port, where the inputs of the ANN are the same as those of the teaching data. This means that those ANN controllers must be retrained when the ship arrives to a new port, which is time-consuming and costly. In this research, by using the head-up coordinate system, which includes the relative bearing and distance from the ship to the berth, a novel ANN controller is proposed to automatically control the ship into the berth in different ports without retraining the ANN structure. Numerical simulations were performed to verify the effectiveness of the proposed controller. First, teaching data were created in the original port to train the neural network; then, the controller was tested for automatic berthing in other ports, where the initial conditions of the inputs in the head-up coordinate system were similar to those of the teaching data in the original port. The results showed that the proposed controller has good performance for ship berthing in ports.