• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.6
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• pp.1239-1248
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• 2021

In this paper, we present FDNN algorithm to perform prediction based on academic understanding. In order to apply prediction based on academic understanding rather than data-dependent prediction to deep learning, we constructed algorithm based on mathematical and hydrology. We construct a model that predicts flow rate of a river as an input of precipitation, and measure the model's performance through K-fold cross validation.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.40 no.4
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• pp.32-48
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• 2022

This study analyzed the construction pattern and historical reality of Gwallamji Pond(觀纜池) in the rear garden of Changdeokgung Palace(昌德宮), which has been received as distorted information and has not received sufficient attention. The main topics consisted of the construction period and reorganization in the pond garden, changes in the installed wooden bridge, the existence of the berthing facility, and whether the plan shape was deformed. The main results of this study can be summarized as follows. First, the Gwallamji Pond was already completed before the Gapsin Coup, which occurred in the year of King Gojong. Since then, the Gwallamji Pond area, including the surrounding facilities, has been neglected for a while and was extensively renovated in the early 1900s. It is difficult to find a clear basis for the suspension and resumption of the Gwallamji Pond construction proposed in the previous discussion. Second, three types of wooden bridges with different shapes and structures were installed sequentially in the Gwallamji Pond. In particular, the second wooden bridge, which installed after the maintenance of the Gwallamji Pond, is judged to be the pontoon bridge depicted in Donggweoldohyeong(東闕圖形), and the railing of the bridge was decorated to symbolize the imperial family of the Korean Empire. The third wooden bridge, which appeared intensively in Japanese colonial era, was a Japanese-style bridge. Third, a berth facility for boarding and disembarking existed on the eastern shore of the Gwallamji Pond. The berth facility is also described in Donggweoldohyeong and it remained until the Japanese colonial period. However, as the maintenance work of the Gwallamji Pond was carried out several times after liberation, the berth facility was gradually damaged, and there are no traces left now. Fourth, The Gwallamji Pond was originally constructed in a planar shape of the Korean Peninsula similar to the present. It is necessary to reconsider the conventional theory that the Gwallamji Pond, made in the shape of a gored-shaped bottle, was renovated in the shape of the Korean Peninsula in Japanese colonial era. Even when the term Pandoji Pond(半島池) first appeared, there was no view that the Japanese intentionally modified the Gwallamji Pond.

• Journal of Korea Society of Digital Industry and Information Management
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• v.19 no.1
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• pp.119-127
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• 2023

Recently, deep learning has been used in the development of various institutional devices and services to help the visually impaired people in their daily lives. This is because not only are there few products and facility guides written in braille, but less than 10% of the visually impaired can use braille. In this paper, we propose a system that recognizes beverage cans in real time and outputs the beverage can name with sound for the convenience of the visually impaired. Five commercially available beverage cans were selected, and a CNN model and a YOLO model were designed to recognize the beverage cans. After augmenting the image data, model training was performed. The accuracy of the proposed CNN model and YOLO model is 91.2% and 90.8%, respectively. For practical verification, a system was built by attaching a camera and speaker to a Raspberry Pi. In the system, the YOLO model was applied. It was confirmed that beverage cans were recognized and output as sound in real time in various environments.

• Journal of the Korea Convergence Society
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• v.12 no.1
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• pp.193-198
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• 2021

In this study, a nano-convergence material technology that can satisfy the superior impact resistance and electrical properties of the semiconducting flame retardant compound used in the Oversheath layer of Extra-high voltage cables was studied. When some of the carbon black used in the semiconducting flame-retardant compound was replaced with CNT (carbon nano tube), the change in physical properties was analyzed. Through the application of carbon nanotubes with remarkably excellent electrical properties, even a small amount of conductive filler formulations can provide superior electrical properties. In addition, as the total filler amount is reduced based on the compound, the workability is improved, and in particular, flexibility and impact resistance are improved, which is expected to contribute to the improvement of the durability of the cable.

• Bulletin of the Korean Space Science Society
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• 2010.04a
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• pp.29.3-29.3
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• 2010

남극세종기지 상공 중간권계면에서의 중량파(gravity wave)를 연구하기 위해 세종기지 유성 레이더로 관측한 유성 에코를 분석하였다. 2007년 이후 유성 에코의 공간적 이동으로부터 유성 관측 고도에서의 수평 바람 정보를 지속적으로 수집해왔다. 80-100 km 고도에서의 바람 프로파일에서 지구 규모의 성분인 평균 바람(Mean wind), 대기 조석 효과(Tides)를 제거하여 국지적인 규모의 중량파에 의한 바람 변화폭(wind variance)을 결정하였다. 월 단위로 평균한 결과로부터 중량파가 계절과 고도에 대한 뚜렷한 특징을 보이고 있음을 확인하였다. 남극 지역에서의 중량파는 동서방향의 바람(zonal wind)와 저층 대기의 남극 소용돌이(vortex)와 깊은 관련이 있을 것으로 생각된다. 남극 반도에 위치한 Rothera 기지에서의 관측 결과와의 비교를 통하여, 남극 반도에서 발생하는 중량파가 중간권과 저층 대기 사이에서 어떤 역할을 하는 지를 확인할 수 있을 것으로 기대한다.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.32 no.4
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• pp.272-275
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• 2019

We investigated the electrical characteristics of amorphous silicon-zinc-tin-oxide (a-SZTO) thin films deposited by RF-magnetron sputtering at room temperature depending on the deposition time. We fabricated a thin film transistor (TFT) with a bottom gate structure and various channel thicknesses. With increasing channel thickness, the threshold voltage shifted negatively from -0.44 V to -2.18 V, the on current ($I_{on}$) and field effect mobility (${\mu}_{FE}$) increased because of increasing carrier concentration. The a-SZTO film was fabricated and analyzed in terms of the contact resistance and channel resistance. In this study, the transmission line method (TLM) was adopted and investigated. With increasing channel thickness, the contact resistance and sheet resistance both decreased.

• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.4
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• pp.625-640
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• 2023

This paper propose a circuit that can measure the inductance of an inductive sensor used in IOT applications. The circuit was constructed using the characteristics of an RL low-pass filter circuit, comparator, current control switch, and capacitor, and the inductance value within the range 1[nH] < L ≤ 1[H] can be derived through the duration time during the output voltage of the RL low-pass filter circuit is greater than the reference voltage.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.spc
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• pp.23-29
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• 2022

To detect harmful chemical substances in seawater, we fabricated a prototype sensor and evaluated its performance. The prototype sensor consisted of a detector, housing, and driving circuit. We built the detector by printing an Indium-Tin-Oxide (ITO) nanoparticle film on a flexible substrate, and it had two detection parts for simultaneous detection of temperature and HNS concentration. The housing connected the detector and the driving circuit and was made of Teflon material to prevent chemical reactions that may affect sensor performance. The driving circuit supplied electric power, and display measured data using a bridge circuit and an Arduino board. We evaluated the sensor performances such as response (ΔR), the limit of detection (LOD), response time, and errors to confirm the specification.

• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.6
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• pp.1171-1176
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• 2023

In this paper, we predicts the estimated price using the DNBP (Deep learning Network to predict Budget Price) model with bidding data obtained from the bidding websites, ElecNet and OK EMS. We use the DNBP model to predict four lottery preliminary price, calculate their arithmetic mean, and then estimate the expected budget price ratio. We evaluate the model's performance by comparing it with the actual expected budget price ratio. We train the DNBP model by removing some of the 15 input nodes. The prediction results showed the lowest RMSE of 0.75788% when the model had 6 input nodes (a, g, h, i, j, k).

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.4
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• pp.425-432
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• 2014

Necessity of compact X-band solid-state weather radar is required to provide weather data, which generate locally in a lot of Korea's mountainous area, rather than tube-type radar. Solid State Power Amplifier (SSPA) for using Dual-polarization method in weather radar is able to obtain desired high output by combining many low output power devices in parallel. Thus, Power combiner applying to high-output power amplifier has disadvantages such as path loss, ballast resistance problem by high frequency and high power, heat release. Therefore, In this paper we demonstrated the excellence of isolation, which is the result from modified Gysel power combiner. As a result, we designed X-band 250W solid state power amplifier with peak power 54dBm, 25% power efficiency for weather radar.