• Proceedings of the Korea Water Resources Association Conference
• /
• 2022.05a
• /
• pp.332-332
• /
• 2022

적설은 지구 기후시스템과 수문순환 과정에서 중요한 역할을 하고 있으며, 겨울철의 적설은 봄철에 녹으면서 식생과 수자원 제공에 큰 영향을 주는 인자로 알려져 있다. 동아시아가 위치한 북반구는 적설량의 90%가 관찰되고 토지의 약 42%가 긴 시간동안 눈으로 덮여 있어 지표 에너지와 물 균형에 영향을 주고, 특히 수자원 관리를 위한 유출이나 토양수분과 같은 수문 인자에 큰 영향을 미친다. 따라서 적설을 정확하게 예측하는 것은 수자원 관리에 있어 매우 중요한 일이다. 한편, 이러한 수문 순환을 정확히 예측하기 위해 수문 분야에서는 지면모형(Land Surface Model, LSM)을 많이 사용하고 있다. 지면모형은 지표면과 대기 사이의 상호작용을 모의하기 위해 개발되었고, 에너지, 수증기, 이산화탄소 등의 다양한 인자들의 교환에 대하여 해석하며, 토양수분, 유출량 등의 수자원 분야의 주요 인자들을 산출하여 수자원 관리에 적극적으로 활용되고 있다. 이에 본 연구에서는 National Center for Atmospheric Research(NCAR)에서 개발한 Community Land Model(CLM)을 사용하여 2001년부터 2016년까지 25km의 공간해상도로 동아시아 지역의 적설 모의를 평가하였다. CLM의 적설 모의 평가 인자는 Snow depth, Snow water equivalent의 2가지 인자를 대상으로 수행하였고, 모의 성능 평가를 위한 관측 자료로 NASA Aqua와 JAXA GCOM-W1 위성에 탑재된 Advanced Microwave Scanning Radiometer(AMSR) 센서에서 제공하는 위성 관측 자료와 Defense Meteorological Satellite Program(DMSP) 위성의 Special Sensor Microwave/Imager(SSM/I) 센서와 Nimbus-7 위성의 Scanning Multichannel Microwave Radiometer(SMMR) 센서에서 제공하는 위성 관측 자료를 기반으로 지상 기상 관측소 자료와 조합하여 재생성한 European Space Agency Global Snow Monitoring for Climate Research (ESA GlobSnow)의 자료를 사용하였다. 그 결과 CLM의 적설 모의는 과대 추정하는 것을 알 수 있었으며, 본 연구의 결과는 동아시아 적설 모의 개선을 위해 자료 동화를 사용하는 후속 연구의 기초자료로 사용할 수 있다.

• Journal of Science Education
• /
• v.40 no.3
• /
• pp.254-266
• /
• 2016

In this study, MBL experiments in the Korean secondary science textbooks and chemistry textbooks under the 2007 and the 2009 curriculum revision were analyzed in terms of curriculum revision era, grade, context of experiment in the textbook, field of science, topic, sensor, and publisher. As a result, 25 MBL experiments were found in the science textbooks under the 2007 revision, and 29 experiments under the 2009 revision (19 for middle school textbook and 10 for high school textbook). MBL experiments in middle school textbooks were not increased after curriculum revision while those in high school textbooks appeared for the first time. Most of them were in the textbooks for grade 7 and presented as an essential experiment rather than optional one. Motion sensor and temperature sensor were used most frequently, and oxygen sensor and carbon dioxide sensor were followed. In aspect of publishers, a frequency of MBL experiment was decreased in most textbook and some publishers didn't include MBL experiment at all. Based on these results, educational implications were discussed.

• Journal of Wetlands Research
• /
• v.22 no.4
• /
• pp.312-320
• /
• 2020

Various LIDs with natural water circulation function are applied to reduce urban environmental problems and environmental impact of development projects. However, excessive Infiltration and evaporation of LID facilities dry the LID internal soil, thus reducing plant and microbial activity and reducing environmental re duction ability. The purpose of this study was to develop a real-time measurement system with complex sensors to derive the management plan of LID facilities. The test of measurable sensors and Internet of Things (IoT) application was conducted in artificial wetlands shaped in acrylic boxes. The applied sensors were intended to be built at a low cost considering the distributed LID and were based on Arduino and Raspberry Pi, which are relatively inexpensive and commercialized. In addition, the goal was to develop complex sensor measurements to analyze the current state o f LID facilities and the effects of maintenance and abnormal weather conditions. Sensors are required to measure wind direction, wind speed, rainfall, carbon dioxide, Micro-dust, temperature and humidity, acidity, and location information in real time. Data collection devices, storage server programs, and operation programs for PC and mobile devices were developed to collect, transmit and check the results of measured data from applied sensors. The measurements obtained through each sensor are passed through the Wifi module to the management server and stored on the database server in real time. Analysis of the four-month measurement result values conducted in this study confirmed the stability and applicability of ICT technology application to LID facilities. Real-time measured values are found to be able to utilize big data to evaluate the functions of LID facilities and derive maintenance measures.

• Journal of Sensor Science and Technology
• /
• v.6 no.3
• /
• pp.207-213
• /
• 1997

A field effect transistor(FET) type dissolved carbon dioxide($pCO_{2}$) sensor with a double layer structure of hydrogel membrane and $CO_{2}$ gas permeable membrane was fabricated by utilizing a $H^{+}$ ion selective field effect transistor(pH-ISFET) with Ag/AgCl reference electrode as a base chip. Formation of hydrogel membrane with photo-crosslinkable PVA-SbQ or PVP-PVAc/photosensitizer system was not suitable with the photolithographic process. Furthermore, hydrogel membrane on pH-ISFET base chip could be fabricated by photolithographic method with the aid of N,N,N',N'-tetramethyl othylenediarnine(TED) as $O_{2}$ quencher without using polyester film as a $O_{2}$ blanket during UV irradiation process. Photosensitive urethane acrylate type oligomer was used as gas permeable membrane on top of hydrogel layer. The FET type $pCO_{2}$ sensor fabricated by photolithographic method showed good linearity (linear calibration curve) in the range of $10^{-3}{\sim}10^{0}\;mol/{\ell}$ of dissolved $CO_{2}$ in aqueous solution with high sensitivity.

• Journal of Sensor Science and Technology
• /
• v.11 no.5
• /
• pp.279-285
• /
• 2002

Two $SnO_2$ based sensing films(pure $SnO_2$ and $SnO_2$/Pt) and a Pt thin film for temperature sensor on an alumina substrate were designed and fabricated for classifying the indoor environmental gases. By controlling the heating power in the shape of trapezoid, unique four sensing response curves created from both $SnO_2$ film and $SnO_2$/Pt film. Then, various parameters were extracted from sensing response curves and carried out principal component analysis(PCA). The results confirm that a sensor array with the proposed operating mode was extremely effective in classifying indoor environmental gases such as $CO_2$, $C_3H_8$, $C_4H_{10}$.

• Fire Science and Engineering
• /
• v.29 no.6
• /
• pp.98-108
• /
• 2015

An integrated command system is critical for the safety of firefighters and effective work in the headquarters of a special disaster areas such as natural disaster or large man-made hazard. The integrated command system requires environmental information such as temperature, humidity, and $CO_2$ levels, as well as personal physical information such as pulse and air respirator levels. An Analog to Digital Converter (ADC) chip converts sensed information into digital signals, and a Micro Controller Unit (MCU) transmits the digital signals to a transmission board using serial communication through a Serial Peripheral Interface (SPI). The digital signals are saved in a transmission board and transmitted to the integrated command system by a Radio Frequency (RF) unit. The location of fire-fighters in a building are determined using a gyro sensor and an inertial sensor. The collected information is applied to the integrated command system for firefighter safety and to ensure that they can effectively carry out their duties. Tthis study theoretically and experimentally investigated the technologies of RF transmission, indoor position, and an integrated command system that supports decision making using the transmitted information.

• Proceedings of the Membrane Society of Korea Conference
• /
• 1995.04a
• /
• pp.52-53
• /
• 1995

현재 상용화 되어있는 산소/질소 분리용 고분자 분리막은 비교적 낮은 선택도를 가지고 있다. 즉, 이점은 확산도와 용해도를 조절함으로써 분리막의 투과선택도를 높일 수 있는 가능성을 보여주고 있으며 보다 높은 투과도와 투과선택도를 갖는 새로운 고분자 재료의 선택이 분리막을 통한 기체 분리나 그 상업적 이용에 절실히 요구되고 있다. PSf는 상용성, 화학적 내구력, 강도, 높은 유리전이온도와 우수한 기체투과성질을 가진 고분자로 분리막에 많이 응용되고 있다. Erb 등은 용매로 DMF(dimethylformamide)와 THF(tetrahydrofuran)를 사용하여 막을 제조하였다. 상부 흐름압력이 5atm일때 각 기체의 투과도 계수는, 헬륨이 11, 이산화탄소가 5.5, 메탄이 0.5, 질소가 0.2였으며, PSf막에 대한 각 기체의 투과는 Henry mode보다 Langmuir mode에서 더욱 우세하게 일어난다고 생각하였다. 또한 Ghosal 등은 PSf에 nitro기를 도입한 nitrated PSf의 투과특성을 조사하였다. 실험결과 nitro group이 치환된 PSf막이 nitro group이 없는 막에 비해 투과도는 낮았지만 선택도는 증가하였다. 구조가 다른 여러가지의 PSf막을 통한 기체 투과성질은 Ghem 등에 의해 밝혀졌다. Membrane-covered probes를 이용한 폴라로그램(polarogram) 방법은 산소를 측정하는데 가장 보편적인 방업ㅂ으로, 산소 탐침(oxygen probe)의 원리는 소위 효소 전극을 발전시키는데 이용되어 왔다. 효소전극은 산소와 실험하고자 하는 물질간의 특정한 효소반응에 기초를 둔 다양한 물질의 선택적 측정을 위한 것이다. 이때 센서에 응용되는 합성막은 산소에 대해 선택적인 투과를 해야하며, 상대적으로 높은 산소확산계수와 물에 대해서는 낮은 투과도를 가져야 한다. 높은 산소확산계수는 반응을 빠르게 하는 잇점이 있으며 물에 대한 낮은 투과도는 센서내의 전해질 물질을 유지보호하는 역할을 한다. 분리막이 산소전극에 이용될 경우 높은 산소 확산계수 이외에도 적절한 기계적 강도, 열적 안정성 등이 요구된다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2016.10a
• /
• pp.549-551
• /
• 2016

In this paper, With the development of modern science and technology are Sheds to stay indoors rather than outdoors space it increased significantly compared to the past. And a wide variety of research about outdoor air quality until recently, efforts are underway but the issue of air quality in the room is the fact that all considered relatively lightly. As the contamination of the room air is polluted, unlike the natural environment, a large outdoor air dilution rate, the dilution rate is very low, once the contaminated air continuously circulating exerts a very bad influence on the health of people staying in the room. In this study, movement characteristics of the person living in a room, the air measuring device for the study of the active indoor environmental control system reflects the life form to measure the quality of the measured air in real time for transmitting the information to the user of the smart devices, alarm bot It was implemented and operational applications.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.15 no.1
• /
• pp.14-26
• /
• 2022

Recently, according to the severity of air pollution, interest in air pollution is increasing. The IoT based fine dust monitoring system proposed in this paper allows the measurement and monitoring of fine dust, volatile organic compounds, carbon dioxide, etc., which are the biggest causes affecting the human body among air environmental pollution. The proposed system consisted of a device that measures atmospheric environment information, a server system for storing and analyzing measured information, an integrated monitoring management system for administrators and smart phone applications for users to enable visualization analysis of atmospheric environment information in real time. In addition, the effectiveness of the proposed fine dust monitoring system based on the Internet of Things was verified by using the response speed of the system, the transmission speed of the sensor data, and the measurement error of the sensor. The fine dust monitoring system based on the Internet of Things proposed in this paper is expected to increase user convenience and efficiency of the system by visualizing the air pollution condition after measuring the air environment information with portable fine dust measuring device.

• Journal of Sensor Science and Technology
• /
• v.31 no.5
• /
• pp.343-347
• /
• 2022

Recently, the problem of global warming caused by greenhouse gases is getting serious due to the development of industry and the increase in transportation means. Accordingly, the need for a technology to reduce carbon dioxide, which accounts for most of the greenhouse gas, is increasing. Among them, a catalyst for converting carbon dioxide into fuel is being actively studied. Catalysts for reducing carbon dioxide are classified into thermal catalysts and photocatalysts. In particular, the photocatalyst has the advantage that carbon dioxide can be reduced only by irradiating ultraviolet rays at room temperature without high temperature or additional gas. TiO₂ is widely used as a photocatalyst because it is non-toxic and has high stability, but has a disadvantage of low carbon dioxide reduction efficiency. To increase the reduction efficiency, 1-propanol was used in the synthesis process. This prevents agglomeration of the catalyst and increases the specific surface area and pores of TiO₂, thereby increasing the surface area in contact with carbon dioxide. As a result of measuring the CO₂ reduction efficiency, it was confirmed that the efficiency of TiO₂ with 1-propanol and TiO₂ without 1-propanol was 19% and 12.3%, respectively, and the former showed a 1.5 times improved efficiency.