• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
• /
• v.12 no.2
• /
• pp.62-70
• /
• 2001

우리 나라 인구의 절반 정도에 해당하는 수의 이동통신 전화가 사용되고 있다. 이동 전화 사용자의 수는 앞으로 더욱 증가할 것이며, 또한 이를 이용한 각종 정보의 교환이 늘어남으로써 개인당 사용량도 늘어날 것으로 생각된다. 사용빈도의 증가와 더불어 이동전화에 의한 뇌종양, 유방암 및 기형 등 각종 인체 질환 발생 가능성에 대한 우려가 늘어나고 있다. 이러한 이동통신 주파수 대역 전자파는 크게 이미 잘 알려진 전자기장이나 자외선, 방사선 등과 인체에 대한 효과가 비슷할 것이라고 생각할 수 있다. 물론 이들은 주파수 대역이 전혀 다르며 이에 따라 서로 다른 물리적 성질을 가지고 있다. 단순히 보유하고 있는 에너지의 크기만으로 비교할 수 있는 것이 아닌 것이다. 그럼에도 불구하고 자외선이나 방사선처럼 전자파도 인체 질환을 유도할 것으로 생각하고 있다. 전자통신제품 사용의 증가에 따라 전자파에 대한 생체 영향에 대한 연구결과들이 발표되고 있다. 특히 이동통신 사용에 따라 암발생이 증가하고 기형이 발생할 수 있다는 역학 및 생물학 연구 결과들이 있었다. 하지만 이 보다 더 많은 수의 논문들이 전자파와 종양 발생이 관련 없다고 얘기하고 있다. 이에 대한 논란은 더 많은 연구와 토론이 필요할 것이다. 정확한 이동전화 주파수대역 전자파가 생체에서 어떻게 작용하는지 알기 위해서는 전자파 자체의 생물리학적 작용기전에 대한 이해가 필요하다. 전자파에 대한 인체 영향을 정확히 분석하기 위해서는 DNA나 단백질 같은 분자수준에서 세포나 실험동물에서 어떤 변화가 발생하는지 분석하는 것이 필요하다. 세포 수준의 연구는 전자파와 한 종류의 세포의 관계를 직접 분석할 수 있다. 세포내에서 DNA나 단백질의 변화는 바로 조직 및 장기내에서의 변화를 의미한다. 하지만 생체내에서는 하나의 세포가 외부 자극에 반응하는 것보다 면역계, 신경계 및 순환계 등 타 장기나 세포의 영향이 존재하는 상황이다. 따라서 세포 수준에서 전자파만의 효과를 장기나 개체내에서 분석하는 전자파에 의한 종양발생 관계를 더 정확히 알 수 있을 것이다. 전자파 중에서 이동전화 주파수 대역에 대한 생체 연구는 많지 않으나 이들로부터 이 주파수 대역의 전자파에 대한 생체 영향 평가 자료를 많이 모을 수 있다. 이러한 자료를 이용하면 핸드폰과 전자파에 대한 위해성 평가를 할 수 있다. 앞으로 다양한 수준에서 생체 영향을 분석함으로써 전자파 노출에 대한 효과를 알 수 있을 것이다.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.10 no.3
• /
• pp.333-340
• /
• 2015

In this paper, we propose a passive microwave sensor for detecting human body using microwave radiometer technologies. The proposed sensor detects human body by measuring the change of the received radiation power from fixed background object due to human body. A C-band microwave radiometer is designed and implemented. The received radiation power changes due to human body is measured by the C-band microwave radiometer, and the effectiveness of the proposed sensor is evaluated by the measurement result analysis.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.11 no.9
• /
• pp.1749-1754
• /
• 2007

In this paper, we propose a new Intra-body communication system for bio-sensor which is one of applications in PAN(Personal Area Network) using body channel. The communication systems for bio-sensor network usually transmits a lot of data acquired in sensor to the receiver in wrist or waist. So we deign the intra-body modem with high data rate, low power, and small size which are achieved by baseband communication techniques. It is noted that the baseband transmission does not requires any analog IF and RF frontends, and can be operated in lower frequency than bandpass transmission. The proposed modem operates at 10MHz band according to the characteristics of intra-body channel, and shows the capability of 5Mbps data rate at distance of 20cm, with $BER=10^{-5}$. In addition, we implement the modem within $2{\times}2cm$ area.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.10 no.7
• /
• pp.1095-1103
• /
• 1999

Presently, the retractable phone with a whip antenna composed of a helix and a monopole is most widely used for cellular mobile communications. However, since the length of the monopole is usually about λ/4, the strong radiated electric fields are produced in the region where the auricle of a head is contacted directly. This field distribution results in high specific absorption rates(SAR's) in the head. In this paper, SAR distributions and local SAR values for the inversely shaped phone(ISP) whose antenna arrangement is opposite to the original retractable phone(ORP) are compared with those for the ORP. This phone is accomplished by mounting the $\lambda$/4-whip antenna on the bottom, not on the top of the handset. The time-averaged field distribution in a computational space including a human model and a phone model is computed using the finite-difference time-domain(FDTD) method. SAR distributions and local SAR values for these phones are calculated with the field distributions. An anatomical head model and an approximate hand model were used to consider a real situation. From the analyzed data, it is shown that this arrangement of the antenna considerably reduces the spatial peak SAR in a human head.

• Information and Communications Magazine
• /
• v.25 no.2
• /
• pp.41-46
• /
• 2008

무선 캡슐형 내시경 시스템 설계를 위하여 인체내부에서 표면까지의 전송손실을 $0.001{\sim}2$ GHz대역에 대하여 분석하였다. 실제 인체구조 모델에 안테나를 적용하여 계산결과를 얻은 기존 연구와 달리 인체내 매질의 평균적 특성을 갖는 균일 매질로 가정하여 안테나의 Q와 효율을 계산하였다. 계산 결과 40MHz의 HPBW(Half-Power Bandwidth), 5mm반경 크기의 송신안테나, 15un거리에 대하여 $400{\sim}600$MHz 사이에서 -58dB가량의 최적 손실이 예상되었다. 분석된 손실 결과를 바탕으로 450MHz에서 무선 캡슐형 내시경 시스템이 설계 및 제작되었고 실제 유사매질용액에서 실험결과 15cm/10cm거리에서 -62/-5ldB의 손실을 보였으며 동물실험에서는 돼지 체내외간 10cm가량의 거리에 대해 약 -56dB의 손실이 측정되었다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.25 no.1
• /
• pp.25-31
• /
• 2014

In this paper, a modified Alford loop antenna for on-body communication system is proposed. The proposed antenna operating in the ISM band is designed with consideration of human body effect. One of advantages of the Alford loop antenna structure is low-profile, however the Alford loop antenna is not suitable for on-body devices since it does not have a ground plane for other electronic part of on-body system and requires balanced feeding structure. To be embedded on on-body devices, the proposed antenna is design with the unbalanced feed structure and ground. The performance of the proposed antenna is simulated and measured when it is placed on the human body phantom to consider the effect of the human body. The proposed antenna a 10 dB return loss bandwidth over the ISM band and monopole-like radiation pattern with low-profile. The antenna has the surface of appropriate for on-body communication environment.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.14 no.6
• /
• pp.1019-1024
• /
• 2019

In this paper, we plan to design and manufacture a new sleeping child check system using image and PIR sensors. Therefore, it plans to implement a system that can prevent in-vehicle accidents that can occur due to presence of human and certain temperature inside the vehicle by collecting data from PIR sensors and temperature sensors with the main control device based on Arduino. In addition, the values of sensors can be linked with Bluetooth communication or Wi-Fi communication to send information to the mobile phone, and the sensor values can be printed by texting on the screen. It also plans to use raspberry pie and camera modules to build a display and smartphone streaming service inside the vehicle. Through this, the objective of this study is to prevent safety accidents in school vehicles by making experiments and research in this paper recognize 100% inside the vehicle with the quantitative goal of PIR sensors.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.23 no.3
• /
• pp.314-319
• /
• 2012

In this paper, a repeater antenna operating at MICS and ISM bands is proposed and the antenna performance including the human body effect is investigated. The proposed antenna is composed of a ZOR(Zeroth Order Resonator) and a loop antenna. A loop antenna is operated at ISM band and a loop antenna capacitively coupled with a ZOR acts as an antenna for MICS band. Simulation was carried out in order to analyze the effects of human body on antenna performance when a human body is located in the near field of an antenna. According to the simulated and measured results, the proposed antenna has -10 dB $S_{11}$ bandwidth wide enough to cover both MICS and ISM bands. The measured peak gains are -28.53 dBi and 3.85 dBi at MICS and ISM band, respectively. The dual band and radiation properties of the proposed antenna are well suited for the WBAN repeater system.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.11 no.10
• /
• pp.969-982
• /
• 2016

Recently, the researches to discovery drug candidates from natural herbs have received considerable attention. In human body, enzyme mostly metabolize the compounds of natural herbs. In this study, we analysis the enzyme interactions using assoication mining. We get this data from BRENDA(: BRaunschweig ENzyme DAtabase) system. Based on enzyme interaction model, we divide the metabolites into substrate metabolites, product metabolites, inhibitor metabolites, and activating metabolites. We then compose substrate metabolite transaction, product metabolite transaction with each metabolites and enzyme interaction transaction with all metabolites. Also we take account of organism for each transactions. We mine frequent metabolites and patterns from six transactions using association rule mining. And we analysis the relationship among metabolites. As a result, we identify the distributions and patterns of metabolites consist in enzyme interactions. We found that metabolites include in only substrate are identified and have very low supports. This results can be useful to develop the effective metabolism prediction model for compounds of natural herbs.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.37 no.4C
• /
• pp.329-337
• /
• 2012

Capsule Endoscope(CE) is a capsule-shaped electronic device which can examine the lesions in digestive tract of human body. Recently the medical procedure using capsule endoscope is receiving great attention to both doctors and patients, since the conventional push-typed endoscope using cables brings great pain and fear to the patients. The technique was firstly available in 2000 and is based on a convergence techniques among BT(Bio Technology), IT(Information Technology), and NT(Nano Technology). The device consists of an optical parts including LEDs(Light Emitting Diodes), an image sensor, a communication module and a power module. Capsule endoscope is the embodiment of the state-of-the art technology and requires key technologies in the various engineering fields. Therefore, in this paper, we introduce the composition of the capsule endoscope system, and compare the communication method between RF(Radio Frequency) communication and HBC(Human Body Communication), which are typically used for data transmission in the capsule endoscope. Furthermore, we analyze the specification of commercialized capsule endoscopes and present the future developments and technical challenges.