• Journal of KIISE:Computing Practices and Letters
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• v.16 no.11
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• pp.1021-1030
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• 2010

In the sensor network, many tiny nodes construct Ad-Hoc network using wireless interface. As this type of system consists of thousands of nodes, managing each sensor node in real world after deploying them is very difficult. In order to install the sensor network successfully, it is necessary to verify its software using a simulator beforehand. In fact Sensor network simulators require high fidelity and timing accuracy to be used as a design, implementation, and evaluation tool of wireless sensor networks. Cycle-accurate, instruction-level simulation is the known solution for those purposes. In this paper, we developed an instruction-level sensor network simulator for Telos sensor node as named TeloSlM. It consists of MSP430 and CC2420. Recently, Telos is the most popular mote because MSP430 can consume the minimum energy in recent motes and CC2420 can support Zigbee. So that TeloSlM can provide the easy way for the developers to verify software. It is cycle-accurate in instruction-level simulator that is indispensable for OS and the specific functions and can simulate scalable sensor network at the same time. In addition, TeloSlM provides the GUI Tool to show result easily.

• Proceedings of the KSCN Conference
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• 2003.11a
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• pp.1074-1075
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• 2003

WTO 출범 이후 우리나라 국민의 식생활 중 수입식품이 차지하는 비중이 급속히 늘어나면서 수입식품 자체의 위해성과 수입농산물에 관한 지식이나 정보가 소비자들에게 부족하여 올바른 구입과 소비가 어렵게 되어 피해를 당하는 경우도 발생하고 있다. 본 연구에서는 청주지역 주부들을 대상으로 수입식품 이용과 인식도 및 수입식품 분별능력의 조사를 통하여, 교육의 필요성여부를 검토하였다. 조사 대상자는 청주시에 거주하는 주부 183명이었고, 조사기간은 2003년 3월 1일부터 3월 15일까지였다. 조사내용은 조사대상자의 일반사항, 식품구입시 태도, 수입식품 구입 경험, 수입식품에 대한 인식도, 수입식품과 국산식품의 분별력 테스트로 구성되었으며, 인식도는 5점 척도에 의해 조사되었다. 사용된 통계처리 방법은 SAS program을 사용하여 빈도, 백분율, 평균, 표준편차를 구하였고, Chi-square 또는 ANOVA로 검정하였다. 연구결과는 다음과 같다. 국내산과 수입산 표시의 확인여부는 응답자의 92.3%가 확인한다고 응답하였고, 선호도를 조사한 결과 99.5%가 국내산을 선호하는 것으로 나타났다. 선호하는 주된 이유로는 ‘수입산은 유해물질이 많으므로’라는 응답이 46.3%로 가장 많이 나타났고, 수입식품 구입경험의 유무로는 92.3%가 경험이 있다고 응답하였으며, 구입동기에 대해 ‘수입산이 시중에 많아 쉽게 구입할 수 있기 때문에’라는 응답이 61.6%로 가장 많았다. 또한 수입식품을 국산식품으로 혼동하여 구입한 경험으로는 응답자의 76%가 ‘있다’고 응답하였으며 혼동한 이유로는 ‘수입식품과 국산식품의 구분이 명확하지 않아서’ 49.6%, ‘수입산과 국내산의 표시가 명확하지 않아서’ 41%를 차지했다. 국내산과 수입산 표시에 대한 신뢰도는 89.7%가 대체로 신뢰하지 않는 것으로 나타났다. 신뢰하지 않는 이유로는 ‘허위표시에 대한 보도를 많이 접해서’가 56.l%로 가장 많은 비율을 차지했다. 수입식품의 인식도를 품질, 가격, 포장 용기, 맛, 조리편리성, 안전성, 건강에 미치는 영향의 7가지 측면에서 살펴보았는데, 수입식품의 품질과 맛에서 국내산과 비슷하거나 나쁘다고 인지하였고, 가격은 수입식품이 싸다고 인지하고 있었으며 연령과 유의성을 보였다(p <0.01). 포장 용기와 조리편리성에 대해서는 국내산과 비슷하거나 좋다고 인지하고 있었으며, 조리편리성은 학력과 유의성이 높게 나타났다(p < 0.01). 안전성과 건강에 미치는 영향에 대해서는 나쁘다고 인지하고 있었다. 수입식품과 국산식품의 분별정도는 66.1%가 구별하는 능력이 언다고 응답하였다. 분별정보를 얻는 경로로는 ‘TV 및 라디오 프로그램’이 61.7%로 가장 많았다. 수입식품에 관한 교육을 받을 의향에 있어서 61.5%가 ‘예’라고 응답하였고, 필요한 교육에 대해 ‘국산식품과 수입식품의 분별법에 관한 내용’이 75.4%로 가장 많았다. 수입식품 분별력 테스트에 있어서는 40점 만점에 평균이 13.6 $\pm$ 7.4점으로 낮았고, 분별력이 가장 좋은 품목은 고사리(53.6%), 분별력이 가장 낮은 품목은 고춧가루(40.4%)로 나타났다. 분별정도에 있어서 ‘매우 잘 구별한다’고 응답한 사람일수록 분별력 점수가 높게 나타나 주부들이 자신의 분별능력에 대해 매우 잘 인지하고 있다는 것을 알 수 있었다(p<0.001). 이상의 결과를 통하여 대부분의 응답자가 수입산에 대해 부정적인 태도를 보이고 있으나 대부분 구입경험이 있고, 분별력 점수도 낮은 편이었다. 따라서 국내 소비자들의 피해를 줄이기 위하여는 수입식품과 국내식품의 특징 및 분별법에 대한 대중매체를 통한 홍보와 이에 대한 교육의 기회가 확대되어져야 하겠다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.10
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• pp.86-92
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• 2016

A high-capacity battery installed in a hybrid vehicle or electric vehicle is used to power, or as a power supply for, electric sub-assemblies. In order to use a high-capacity battery as a power supply for electric sub-assemblies, such as an electronic control unit or for lighting, radio, and navigation, there is a need for a DC converter that changes a high voltage of 240-400V to a low voltage of 12-14V, which is done with a low-voltage DC-DC converter (LDC). An LDC undergoes long-term aging so as to reduce latent defects in the production process. With regard to the usual aging method, an LDC is a DC-DC converter. So, a DC power supply is connected and used as input, and a programmable DC electronic load is the output. For stable operation, a product having a larger capacity by 10% (compared to an LDC) is used, and has a structure where electric power is dissipated into 100% heat. So, there is a problem with volume, based on the use of two pieces of equipment to test the LDC, and another problem based on the generation of heat in the programmable DC electronic load. Hence, this paper suggests a load test method as a way of recycling, where a significant portion of the electricity dissipated as heat in a load tester is returned as input. The method realizes savings of 80% or more in the electricity dissipated as heat through improvement in the efficiency of the recycling load tester.

• Journal of the Korean Institute of Gas
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• v.2 no.4
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• pp.79-84
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• 1998

This paper describes the minimum ignition limit voltages for LPG-Air 5.25[Vol$\%$] mixture gas by discharge sparks in radio-frequency limits using RF power supply and IEC type ignition spark apparatus. As a result, the minimum ignition limit voltages is increased in proportional to the rate of increasing of frequency in LPG-Air mixture gas. Especially, the minimum ignition limit voltages increase remarkably between 3[KHz] and 10[KHz]. It is considered that ignition is caused by one discharge until 3[KHz] and, beyond 3[KHz] ignitiof is caused by more than two discharges. The reason is analyzed that energy loss is caused by existing pause interval between discharges. It is considered that the result can be used for not only data for researches and development of intrinsically safe explosion-proof RF machines which are applied tole-equipments and detectors used in dangerous areas but also for datum for its equipment tests.

• Korean Journal of Remote Sensing
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• v.25 no.1
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• pp.45-59
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• 2009

This research presents the effect of Asian dust on the derived sea surface temperature (SST) from measurements of the Advanced Very High Resolution Radiometer (AVHRR) instrument flown onboard NOAA polar orbiting satellites. To analyze the effect, A VHRR infrared brightness temperature (TB) is estimated from simulated radiance calculated from radiative transfer model on various atmospheric conditions. Vertical profiles of temperature, pressure, and humidity from radiosonde observation are used to build up the East Asian atmospheric conditions in spring. Aerosol optical thickness (AOT) and size distribution are derived from skyradiation measurements to be used as inputs to the radiative transfer model. The simulation results show that single channel TB at window region is depressed under the Asian dust condition. The magnitude of depression is about 2K at nadir under moderate aerosol loading, but the magnitude reaches up to 4K at slant path. The dual channel difference (DCD) in spilt window region is also reduced under the Asian dust condition, but the reduction of DCD is much smaller than that shown in single channel TB simulation. Owing to the depression of TB, SST has cold bias. In addition, the effect of AOT on SST is amplified at large satellite zenith angle (SZA), resulting in high variance in derived SSTs. The SST depression due to the presence of Asian dust can be expressed as a linear function of AOT and SZA. On the basis of this relationship, the effect of Asian dust on the SST retrieval from the conventional daytime multi-channel SST algorithm can be derived as a function of AOT and SZA.

• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.264-264
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• 2017

국외의 상수도 원격검침 시스템 내 데이터 전송방식은 도시 규모, 계량기의 밀도, 전력공급 여부 및 통신망의 설치 여부 등을 종합적으로 고려하여 결정되었다. 대부분의 스마트워터미터 제조업체들은 계량기의 부호기가 공급하는 판독 내용(데이터)을 전송할 검침단말기와 근거리 통신망(neighborhood area network)을 연계하여 개발 및 판매하였으며, 자체 소유 통신 프로토콜을 사용하여 라디오 주파수(RF) 통신 기술을 사용하고 있다. 광역통신망(wide area network)의 경우, 노드(말단의 계량기 및 센서)들과 이에 연결된 통신망 들을 포함한 네트웍의 배열이나 구성이 스타(star), 메쉬(mesh), 버스(bus), 나무(tree) 등의 형태로 통신망이 구성되어 있으나, 스타와 메쉬형 통신망 구성형태가 가장 널리 활용되는 것으로 조사되었다. 시스템 통합운영관리 업체들인 IBM, Oracle, Itron 등은 용수 인프라 관리 또는 통합네트워크 솔루션 등의 통합 물관리 시스템(integrated water management system)을 개발하여 현장적용을 하고 있으며, 원격검침 시스템을 통해 고객들의 현재 소비량과 과거 누적 소비량, 누수 감지 서비스 및 실시간 요금 고지 등을 실시간으로 웹 포털과 앱을 통해 제공하고 있다. 또한, 일부 제조업체들은 도시 용수공급/소비 관리자가 주민의 용수사용량을 모니터링하여 일평균 용수사용량 및 사용 경향을 파악하고, 누수를 검지하여 복구 및 용수 사용 지속가능성 지수를 제시하고, 실시간으로 주민의 용수사용량 관련 데이터를 모니터링하여 용수공급의 최적화를 위한 의사결정지원 서비스를 용수공급자에게 제공하고 있다. 최근에는 인공지능을 활용해 가정용수의 용도별(세탁용수, 화장실용수, 샤워용수, 식기세척용수 등) 사용량 곡선을 패터닝하여 profiling 기법을 도입해, 스마트워터미터에서 용수사용량이 통합되어 검지될 시 용수사용량의 세부 용도별 re-profiling 기법을 도입하여 가정용수내 과소비되는 지점을 도출 후 절감을 유도하는 기술이 개발 중이다. 또한, 미래 용수 사용량 예측을 위해 다양한 시계열 자료를 분석하는 선형 종속 모형(자기회귀모형, 자기회귀이동평균모형, 자기회귀적분이동평균모형 등)과 비선형 종속 모형(Fuzzy Logic, Neural Network, Genetic Algorithm 등)을 활용한 예측기능이 구축되어 상호 비교하여 최적의 용수사용량 예측 도구를 제공되고 있다.

• Journal of the Korean earth science society
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• v.42 no.5
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• pp.504-513
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• 2021

Different physical processes, according to the atmospheric boundary layer types, were used in the Local Data Assimilation and Prediction System (LDAPS) of the Unified Model (UM) used by the Korea Meteorological Administration (KMA). Therefore, it is important to verify the atmospheric boundary layer types in the numerical model to improve the accuracy of the models performance. In this study, the atmospheric boundary layer types were verified using observational data. To classify the atmospheric boundary layer types, summer intensive observation data from radiosonde, flux observation instruments, Doppler wind Light Detection and Ranging(LIDAR) and ceilometer were used. A total number of 201 observation data points were analyzed over the course 61 days from June 18 to August 17, 2019. The most frequent types of differences between LDAPS and observed data were type 1 in LDAPS and type 2 in observed(each 53 times). And type 3 difference was observed in LDAPS and type 5 and 6 were observed 24 and 15 times, respectively. It was because of the simulation performance of the Cloud Physics such as that associated with the simulation of decoupled stratocumulus and cumulus cloud. Therefore, to improve the numerical model, cloud physics aspects should be considered in the atmospheric boundary layer type classification.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.4
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• pp.250-263
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• 2019

This study aimed to improve the public perception of people with mental illness by suggesting the need for public efforts and proposing specific plans. Demographic differences in the attitudes towards mental illness, the need of public service announcements to improve public perception of mental illness, and the current and expected situation of each advertising medium were analyzed, and plans to improve the advertising were proposed. Three mental illnesses that are possible to recover from through treatment-depression, obsessive-compulsive disorder(OCD), and panic disorder-were examined primarily, and the general public residing in Seoul and the capital area were surveyed. A comparison of the respondents' attitudes towards people with mental illness showed that there were significant differences in their attitudes with respect to gender, marital status, age, and family history. On the other hand, there was no significant difference with respect to religion, monthly income, or academic background. Most of the respondents recognized that public efforts to improve the public perceptions of mental illness, i.e., efforts through the mass media, were necessary and should be intensified though television, Internet, radio, billboard, and transport advertising. Based on the above findings, this study highlights the necessity for advertising through mass media for positive public perceptions of people with mental illness and proposes plans to intensify the advertising, focusing on social, organizational, and individual levels.

• Journal of the Korean Association of Geographic Information Studies
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• v.22 no.1
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• pp.93-102
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• 2019

In this study, in order to analyze the possibility of observing a typhoon track based on the Global Navigation Satellite System(GNSS), Typhoon NARI, the 11th typhoon of 2007, was analyzed in terms of the typhoon track as well as the local variation of perceptible water over time. The perceptible water was estimated using data obtained from observatories located on the typhoon track from Jeju to the southern coast of Korea for a total of 18 days from September 7(DOY 250) to September 24(DOY 267), 2007, including the period when the observatories were affected by the typhoon at full-scale, as well as one previous week and one following week. The results show that the trend of the variation of perceptible water was similar between the observatories near the typhoon track. Variation of perceptible water over time depending on the development and landing of the typhoon was distinctively observed. Several hours after the daily maximum of perceptible water was found at the JEJU Observatory, the first struck by the typhoon on the typhoon track, the maximum value was found at other observatories located on the southern coast. In the observation period, the time point at which the maximum perceptible water was recorded in each location was almost the same as the time point at which the typhoon landed at the location. To analyze the accuracy of the GNSS-based perceptible water measurement, the data were compared with radiosonde-based perceptible water data. The mean error was 0.0cm, and the root mean square error and the standard deviation were both 0.3cm, indicating that the GNSS-based perceptible water data were highly accurate and precise. The results of the this study show that the GNSS-based perceptible water data may be used as highly accurate information for the analysis of typhoon tracks over time.

• Journal of the Korean Society of Earth Science Education
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• v.12 no.1
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• pp.18-26
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• 2019

Vietnam is one of the countries most affected by climate change. Therefore, communication activities on climate change in Vietnam are focused with various media such as television, newspapers, radio, internet etc. In particular, Facebook social network is a potential media but less interested and developed. In this topic, Audience Insight tool of the Facebook social network and the online sociological survey method were conducted to assess the current status and effectiveness of climate change communication activities via Facebook in Vietnam today. Vietnam ranks seventh in the world with 58 million users. However, the number of climate change communication fanpages has only about 15 fanpages with the largest number of followings is 94,721 persons. Among of the 10 most contented Facebook users in Vietnam today, there is no fanpage related to climate change. The results of research and evaluation two fanpages of climate change communication that are the most and most frequent followers in Vietnam showed that climate change communication via Facebook in Vietnam is not as effective as expected. At the same time, online survey results also pointed out the causes of the above problems. This is the scientific basis for management agencies to find the solutions to promote the strength of Facebook social network in climate change communication in the future.