• Animal Bioscience
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• 제34권6호
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• pp.985-992
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• 2021

Objective: Artificial insemination plays an important role in genetic improvement in the goat farming system. The aim of this study was to investigate the effect of cervical application of hyaluronan (HA) on the fertility in goats after cervical artificial insemination using frozen-thawed (F-T) semen. Methods: After oestrous synchronisation with progesterone sponges and pregnant mare serum gonadotropin injection, both nulli- and multi-parous goats, were randomly allocated to 2 groups, and were inseminated with 0.25 mL of F-T semen (150×106 spermatozoa) twice at 52 h and 56 h after sponge removal. Prior to the insemination, goats in Group 1 only were given topical cervical HA application at 48 h after sponge removal. Site of insemination was recorded as os-cervix or intra-cervix or intra-uterus. Pregnancy was tested ultrasonographically 42 days after insemination. The data on pregnancy rates and percentage of animals according to the site of semen deposition were compared by Chi-square analysis. Results: The overall pregnancy rate was significantly (p<0.004) higher in goats with prior application to the cervix with HA (63.3%) than without (36.0%). Same pattern was observed in the pregnancy rates of nulli- and multi-parous goats in both the groups. Percentage of nulliparous goats according to the site of insemination in the HA group did not differ between first and the second insemination. However, in multiparous goats the percentage of animals inseminated intra-cervically was significantly increased (p≤0.05) between the first and the second inseminations. Conclusion: The results suggest that significantly higher fertility rate in the "HA goats" compared to the "without HA" group was because of deeper insemination facilitated by topical cervical application of HA. The deeper insemination into the cervical canal increase the rate of fertilisation when the cervical artificial insemination is performed.

• 한국정보통신학회논문지
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• 제23권10호
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• pp.1188-1194
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• 2019

유체의 흐름을 측정하는 여러 방법 중 열선 풍속 센서는 유체의 열전달에 의해 속도나 온도를 측정하는 장치로 비정상 속도 및 난류 속도 성분을 측정하는데 유용하다. 하지만 열선 풍속 센서는 외부의 환경 요인에 민감하며, 주변 온도, 습도, 신호 잡음 등에 의해 정확도가 떨어지는 단점이 있다. 이런 단점을 보완하는 방법으로 온도 보상 회로를 추가하는 기술이 나오고 있지만 가격 경쟁력을 갖출 수 없는 상황이다. 이를 해결하기 위해 본 논문에서는 온도 보상이 필요 없는 풍속 감지 센서에 대해 연구를 진행하였다. 열선식 풍속 센서는 외부 환경 요인 중에서도 주변 온도에 매우 취약하다. 주변 온도로는 전자 회로에 의한 발열의 영향이 가장 크게 미치고 있으며, 이를 개선하는 방법으로 발열체에 보조 발열체를 추가로 장착하여 보조발열체와 발열체의 일정한 온도차를 제어하는 것이다. 이와 같이 기존 기술에 비해 복잡하지 않은 방법으로 동등한 성능을 확보할 수 있다는 것을 확인할 수 있었다.

• 한국응급구조학회지
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• 제25권1호
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• pp.223-234
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• 2021

Purpose: The purpose of the study is to check up the status of 119 emergency control centers usage. Therefore, the status of use of 119 emergency control centers and the incidence of pre-hospital cardiac arrest patients were investigated. Methods: The emergency activity daily reports and first aid diaries of 119 emergency control centers from January to December 2018 were reviewed. For more accurate status analysis, Among the first aid guidance received in the emergency rescue standard system, the cardiopulmonary resuscitation guide log was reviewed. Results: In 2018, the total usage of the 119 emergency control centers was 1,358,356 calls, hospital guidance werethe most commom (n=629,676, 46.4%), followed by first aid (n=428,027, 31.5%), disease consultation (n=170,238, 12.5%), medical oversight (n=111,188, 8.2%), and interhospital transfer (n=5,052, 0.4%). Regarding the user number per 1,000 persons, Jeju was the greatest at 48.0, whereas Changwon was the lowest at 13.0. A total number of dispatcher-assisted cardiopulmonary resuscitation was 12.181. The time from report to chest compression were 156.2±80.8 seconds for those with previous cardiopulmonary resuscitation training and 168.0±79.3 seconds for those without such training (p<.05). Conclusion: The ratio of first aid instructions, including dispatcher-assisted cardiopulmonary resuscitation, among total usage of the 119 emergency control centers increased. Therefore, additional efforts are required to improve the quality and expertise of information provided through the 119 emergency control centers.

• Journal of Platform Technology
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• 제11권4호
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• pp.3-12
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• 2023

포스트-코로나 시대에는 방역 조치의 중요성이 크게 강조되고 있으며, 이에 맞춰 딥러닝을 이용한 마스크 착용 상태 검출 및 다른 전염병 예방에 관련된 연구가 진행되고 있다. 그러나 질병 확산 방지를 위한 문화시설 관람객 탐지 및 추적 연구도 마찬가지로 중요하므로 이에 대한 연구가 진행되어야 한다. 본 논문에서는 사전 수집된 데이터 셋을 이용하여 컨볼루션 신경망 기반 객체 탐지 모델을 전이 학습시키고, 학습된 탐지 모델의 가중치를 다중 객체 추적 모델에 적용하여 방문객을 모니터링 한다. 방문객 탐지 모델은 Precision 96.3%, Recall 85.2% F1-Score 90.4%의 결과를 보여주었다. 추적 모델의 정량적 결과로 MOTA 65.6%, IDF1 68.3%. HOTA 57.2%의 결과를 보여주었으며, 본 논문의 모델과 다른 다중 객체 추적 모델 간의 정성적 비교에서 우수한 결과를 보여주었다. 본 논문의 연구는 포스트-코로나 시대의 문화시설 내 방역 시스템에 적용될 수 있을 것이다.

• 한국수소및신에너지학회논문집
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• 제33권6호
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• pp.776-785
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• 2022

Hydrogen combustion in modern gas-turbine engine is the cutting edge technology as carbon-free energy conversion system. Flashback of hydrogen flame, however, is inevitable and critical specially for premixed hydrogen combustion. Therefore, this experimental investigation is conducted to understand flashback phenomenon in premixed hydrogen combustion. In order to investigate flashback characteristics in premixed hydrogen (H₂)/air flame, we focus on pressure conditions and nozzle shapes. In general, quenching distance reduces as pressure of combustion chamber increases, causing flashback from boundary layer near wall. The flashback regime for reference and modified candidate configurations can broadly appear with increasing combustion chamber pressure. The later one can improve flashback-resist by compensating flow velocity at wall. Also, improved wall flow velocity profile of suggested contraction nozzle prevents entire flashback but causes local flashback at nozzle exit.

• International Journal of Computer Science & Network Security
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• 제23권7호
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• pp.1-8
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• 2023

An Orthogonal Frequency Division Multiplexing (OFDM) based wireless communication system has drawn wide attention for its high transmission rate and high spectrum efficiency in not only radio but also Underwater Acoustic (UWA) applications. Because of the narrow sub-carrier spacing of OFDM, orthogonality between sub-carriers is easily affected by Doppler effect caused by the movement of transmitter or receiver. Previously, Doppler compensation signal processing algorithm for Desired propagation path was proposed. However, other Doppler shifts caused by delayed Undesired signal arriving from different directions cannot be perfectly compensated. Then Receiver Bit Error Rate (BER) is degraded by Inter-Carrier-Interference (ICI) caused in the case of Multi-path Doppler channel. To mitigate the ICI effect, a modified Delay and Doppler Profiler (mDDP), which estimates not only attenuation, relative delay and Doppler shift but also sampling clock shift of each multi-path component, is proposed. Based on the outputs of mDDP, an ICI canceling multi-tap equalizer is also proposed. Computer simulated performances of one-tap equalizer with the conventional Time domain linear interpolated Channel Transfer Function (CTF) estimator, multi-tap equalizer based on mDDP are compared. According to the simulation results, BER improvement has been observed. Especially, in the condition of 16QAM modulation, transmitting vessel speed of 6m/s, two-path multipath channel with direct path and ocean surface reflection path; more than one order of magnitude BER reduction has been observed at CNR=30dB.

• Imaging Science in Dentistry
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• 제53권4호
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• pp.271-281
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• 2023

Purpose: The objective of this scoping review was to investigate the applicability and performance of various convolutional neural network (CNN) models in tooth numbering on panoramic radiographs, achieved through classification, detection, and segmentation tasks. Materials and Methods: An online search was performed of the PubMed, Science Direct, and Scopus databases. Based on the selection process, 12 studies were included in this review. Results: Eleven studies utilized a CNN model for detection tasks, 5 for classification tasks, and 3 for segmentation tasks in the context of tooth numbering on panoramic radiographs. Most of these studies revealed high performance of various CNN models in automating tooth numbering. However, several studies also highlighted limitations of CNNs, such as the presence of false positives and false negatives in identifying decayed teeth, teeth with crown prosthetics, teeth adjacent to edentulous areas, dental implants, root remnants, wisdom teeth, and root canal-treated teeth. These limitations can be overcome by ensuring both the quality and quantity of datasets, as well as optimizing the CNN architecture. Conclusion: CNNs have demonstrated high performance in automated tooth numbering on panoramic radiographs. Future development of CNN-based models for this purpose should also consider different stages of dentition, such as the primary and mixed dentition stages, as well as the presence of various tooth conditions. Ultimately, an optimized CNN architecture can serve as the foundation for an automated tooth numbering system and for further artificial intelligence research on panoramic radiographs for a variety of purposes.

• 한국운동역학회지
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• 제33권4호
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• pp.175-184
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• 2023

Objective: The purpose of this study is to investigate the effects of human motion and javelin kinematics during the energy transfer in javelin throwing on records, and to provide evidence-based training insights for athletes and coaches to enhance records. Method: Three javelin throw athletes (age: 22.67 ± 0.58 years, height: 178.33 ± 7.37 cm, weight: 83.67 ± 1.15 kg) were recruited for this study. Each athlete attempted ten maximum record trials, and the kinematic data from each performance were analyzed to determine their influence on the records. The Theia3d Markerless system was used for motion analysis. Results: Key factors were modeled and identified at each moment. In E1, main variables were COM Y (𝛽 8.162, p<.05) and COM velocity Z (𝛽 -72.489, p<.05); in E2, COM X (𝛽 -17.604, p<.05); in E3, COM X (𝛽 -18.606, p<.05), COM velocity Y (𝛽 38.694, p<.05), and COM velocity X (𝛽 66.323, p<.05). For the javelin throw dynamics in E3, key determinants were Attitude angle and Javelin velocity in the Y-axis. Conclusion: The study reveals that controlled vertical movement, center of mass management during braking, and enhanced pelvic rotation significantly improve javelin throw performance. These kinematic strategies are critical for record enhancement in javelin throwing.

• Journal of Plant Biotechnology
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• 제31권1호
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• pp.55-60
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• 2004

지황의 부정근을 이용한 기내묘 생산 체계를 확립하였다. 먼저 지황의 잎절편을 2 mg/L IBA혹은 2mg/L NAA를 첨가한 MS고체배지에 치상하여 부정근을 유도하였다. 고체배지에서의 효율적인 증식조건을 확인하기 위해 다양한 옥신 농도에 따른 배지에 부정근을 치상하여 4주간 배양한 후 증식된 부정근의 수와 길이를 측정한 결과 2mg/L IBA조건에서 최적의 생장을 보였다. 상기실험에서 확립된 부정근 증식조건을 이용하여 액체배양을 실시하였으며, 이를 액체 현탁배양하여 액체조건에서의 증식조건을 확립하였다. 또한, 2mg/L IBA가 첨가된 1/3 MS배지 조건에서 생물반응기에 10g의 부정근을 접종하여 6주간 암배양하여 255g의 부정근을 생산할 수 있었으며, 이렇게 생산된 부정근은 2mg/L BA가 첨가된 MS 고체배지에서 신초를 유도하였다. 신초들은 모두 정상적인 생육을 보이며, 식물체로 생장하였으며, 이들 식물체들은 토양으로 옮겨 순화되었다. 따라서 이러한 증식 체계를 이용하여 지황식물체의 대량증식체계를 확립하였다.

• 인터넷정보학회논문지
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• 제20권6호
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• pp.129-135
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• 2019

최근 NFC 내장 단말기(스마트 폰) 사용자의 증가와 더불어 NFC 기반 모바일 환경에서 모바일 상거래 프로세스를 개선하기 위한 연구가 이루어지고 있다. 모바일 전자결제시 인증이 중요하므로 FIDO(Fast IDentity Online) 및 2 Factor 전자결제 시스템을 적용하는 방안이 연구되었다. 또한 최근 4차산업의 대표적 기술로 분산원장을 이용하는 블록체인이 등장하였다. 본 연구에서는 불특정 소수가 참여하는 소규모의 갤러리 경매에서 NFC 내장 단말기(스마트 폰)를 사용하는 거래자들의 모바일 갤러리 경매를 위해서, 경매 참여자들의 전자 결제시 거래 내역과 소유권 이전 등을 기록하기 위해 2 Factor 인증방식으로 패스워드 기반의 인증과 생체인증 기술(지문)을 적용하였다. 그리고, 갤러리 경매 관련 비용 절감과 데이터 무결성을 위해 허가형 분산원장 블록체인을 구성하여 이용하는 방안을 제안하였다. 또한 경매 분야에서 블록체인을 적용한 국내외 사례를 조사하고 제안 방안과 비교, 평가하였다. 향후 연구에서는 제안 방안을 적용하기 위해 블록체인 네트워크와 스마트 계약의 구현 및 블록체인과 인공지능(Artificlal Intelligence)을 접목하는 방안에 대해 연구하고자 한다.