• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.180-180
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• 2012

ADCP는 3차원 유속과 수심을 관측하여 유량을 정확하게 계산하는 데 널리 이용되고 있는 최신계측기기로 국내에서도 유량조사사업단 등 기관에 도입되어 수위-유량관계곡선식의 보정 등에 적용되고 있다. 하지만 ADCP 관측값 중 수심관측 자료를 별도로 활용하는 부분도 많은 관심을 받고 있다. 특히 최근 4대강 사업으로 인한 하상변동 측정에 기존 유량관측용으로 구매된 ADCP를 수심관측용으로 활용할 수 있다. ADCP는 일정한 각도로 경사진 4개의 초음파 빔을 활용하여 사선 방향으로 수심을 각각 관측한다. 최근에는 별도의 수심관측용의 수직 빔을 추가 설치하여 한번 관측에 초당 5개 지점의 수심을 동시에 관측할 수 있어 수심관측용으로도 기존 단독빔 음향측심기에 비해 효율적으로 수심을 관측할 수 있다. 그리고 ADCP는 GPS와 연동되어 수심관측의 3차원 공간정보 (x, y, z)를 창출할 수 있어 기존 GIS 자료와 융합될 수 있다. 하지만 기존의 음향 측심기의 수직빔과 다르게 ADCP의 빔이 일정한 각도로 경사져 있고 선박 활용 관측 시 요동에 의해 흔들려 각각의 빔이 계측한 수심의 수평위치를 정확하게 추출하기 어려운 점이 있다. 특히 경사빔에 의한 수심관측지점에 GPS 정보를 추정하여 부여하는 작업도 까다롭다고 하겠다. 그리고 수심관측자료 자체의 오차나 특이점 제거 등의 보정작업을 거쳐야 하는 문제도 있다. 따라서 원자료를 직접 활용할 수 없고 별도의 후처리 과정을 거쳐야 한다. 따라서 본 연구는 이러한 문제를 해결하기 위해 다음의 알고리즘을 개발하였다: 1) 경사빔에 의한 관측지점의 수평위치 산정, 2) ADCP의 흔들림 (피치와 롤링) 보정, 3) 경사빔의 관측위치에 지리정보부여, 4) 수심관측치 오차와 특이점 보정, 5) 관측자료의 GIS 파일 전환. 이러한 알고리즘은 GUI와 연동되어 적용되었으며 편리하게 이용되도록 구성되었다. 그리고 본 연구는 이러한 ADCP의 수심관측 자료와 하천 및 저수지 등 경계 GIS 파일을 연동시켜 전체 혹은 국부 저수량과 하상변동량을 계상하는 알고리즘도 추가하여 관측자료의 실무에서의 활용성을 증대시키고자 하였다.

• The Journal of the Acoustical Society of Korea
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• v.38 no.4
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• pp.443-449
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• 2019

To protect the patient's internal organs when a patient with cardiovascular disease occurs, it is important to reduce the elapsed time by providing emergency medical services. Decisions for conducting cardiopulmonary resuscitation are mainly made using the carotid palpation method, which directs the pulse of the carotid artery, which can diagnose the patient's condition according to one's own subject and cause cerebral blood flow to be blocked by excessive pressure in the carotid due to the weaken cardiopulmonary function. In this study, we developed a multimodal patch-type probe based on multi-channel ultrasound Doppler pairs and oxygen saturation measurement modules which can monitor cardiopulmonary functions. From the in-vivo experiments, the developed probe can be utilized as a novel tool that can increase the survival rate of cardiovascular disease patients by objectively monitoring the cardiopulmonary function of the patient quantitatively and promptly in an emergency situation.

• Journal of Biomedical Engineering Research
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• v.43 no.5
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• pp.319-330
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• 2022

In this study, the optimal driving frequency was derived through finite element analysis (FEA) to optimize the developed piezoelectric ultrasonic medical devices(PUMD) for bone surgery. The core of the PUMD is the piezoelectric ceramic (PZT), which is a vibrator that generates vibration energy. The piezoelectric ceramic shows the maximum current value with respect to the input voltage at the resonance frequency, which generates the maximum mechanical vibration. In the past, various studies have been conducted related to the analysis of PUMD, but most of the research so far has been limited to free vibration analysis. However, in order to derive the accurate resonant frequency, the initial stress generated by bolt tightening in the bolt-clamped Langevin type transducer (BLT) must be considered. In this study, after designing a PUMD, the driving performance according to the bolt tightening value was analyzed through FEA, and this was experimentally verified. First, the resonance mode and frequency response were confirmed through modal and harmonic analysis at 20-40 kHz, which is known as the optimal driving frequency band of PUMD for bone surgery. In addition, the design of the PUMD was confirmed by checking the mechanical behavior of the tip and the piezoelectric ceramic at the resonant frequency. Consequentially, the characteristic evaluation was performed, and it was confirmed that the resonant frequency result derived through the FEA was reasonable. Through this study, we presented a more rational FEA method than before for BLT transducers. We expect that this will shorten the time and cost of developing a PUMD, and will enable the development of more stable and high-quality products.

• Journal of Korean Medicine Rehabilitation
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• v.32 no.2
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• pp.163-171
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• 2022

The study aimed to understand the knee condition of patients with knee joint pain who visited an Korean Medicine hospital by performing musculoskeletal ultrasound. From July 1, 2021 to October 31, 2021, information on the gender, age, diagnosis, and ultrasound findings of knee joint pain patients were retrospectively collected. To examine the condition of the knee joint, images were taken in a total of three postures. All images were analyzed by an examiner. 7 cases of osteoarthritis, 1 case of medial collateral ligament rupture, and 1 case of quadriceps tendon calcification were collected. It was able to check the condition of articular cartilage, lipoma arborescens, and the formation of osteophytes through musculoskeletal ultrasound. The implementation of musculoskeletal ultrasound can enable Korean medicine doctors to give more active treatment for patients through accurate and scientific diagnosis. Based on more evidence, it is thought that the use of medical devices by Korean medicine doctors will need to be made in the future.

• The Korean Society of Law and Medicine
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• v.24 no.1
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• pp.131-155
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• 2023

Medical act divides unlicensed medical practice into medical practice by non-medical practitioners and unlicensed practice by medical practitioners. In the past, it was a common approach to strictly distinguish between western and Korean medicine, but the Supreme Court's Decision of December 22, 2016, Do. 21314, provided a new direction regarding the criteria for determining whether a Korean medicine practitioner is acting outside license. This paper analyzes the new criteria in detail, examines the significance of the new criteria, and explores its impact on the dualistic medical system. The difference between the new criteria and the previous criteria in the precedents is that the judgment is not based on the connection between Korean medicine principles and Western medicine principles. It is an advanced standard that actively accepts the overlap and variability of medical practice, moving away from dichotomous thinking that exclusively distinguishes between Korean medicine and Western medicine.

• Science of Emotion and Sensibility
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• v.26 no.3
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• pp.149-160
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• 2023

This study develops a time-varying system-based noncontact fabric sensor that can measure cerebral blood-flow signals to explore the possibility of brain blood-signal detection and emotional evaluation. The textile sensor was implemented as a coil-type sensor by combining 30 silver threads of 40 deniers and then embroidering it with the computer machine. For the cerebral blood-flow measurement experiment, subjects were asked to attach a coil-type sensor to the carotid artery area, wear an electrocardiogram (ECG) electrode and a respiration (RSP) measurement belt. In addition, Doppler ultrasonography was performed using an ultrasonic diagnostic device to measure the speed of blood flow. The subject was asked to wear Meta Quest 2, measure the blood-flow change signal when viewing the manipulated image visual stimulus, and fill out an emotional-evaluation questionnaire. The measurement results show that the textile-sensor-measured signal also changes with a change in the blood-flow rate signal measured using the Doppler ultrasonography. These findings verify that the cerebral blood-flow signal can be measured using a coil-type textile sensor. In addition, the HRV extracted from ECG and PLL signals (textile sensor signals) are calculated and compared for emotional evaluation. The comparison results show that for the change in the ratio because of the activation of the sympathetic and parasympathetic nervous systems due to visual stimulation, the values calculated using the textile sensor and ECG signals tend to be similar. In conclusion, a the proposed time-varying system-based coil-type textile sensor can be used to study changes in the cerebral blood flow and monitor emotions.

• Korean Journal of Animal Reproduction
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• v.24 no.2
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• pp.199-208
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• 2000

This study was carried out to investigate of factors concerning to ultrasound-guided follicular aspiration; level of vacuum pressure, diameter of use needle, effect of FSH hormone and conception rate after embryos transfer. 1. Oocytes collection number were 4.2$\pm$2.9 e.a to luteuml phase and follicular phase were 4.4$\pm$3.5 e.a to ovaries of Hanwoo. 2. We taked proper level of aspiration vacuum pressure was 40~120 mmHg to oocytes collection. Oocytes collected number were 4.2$\pm$3.2, 4.3$\pm$3.4, 4.5$\pm$3.4 e.a. to 40, 80, 120mmHg, respectively, follicles aspiration rate were 49, 47, 45%. 3. Effect of collection needle diameter was not difference significantly(P＜0.05), oocytes collected number were 4.4$\pm$3.5 e.a to 170 and 3.0$\pm$1.8 e.a to 18G needle, collected oocytes quality were no difference significantly (P＜0.05). 4. Follicles increase number to FSH hormone injection were 6.2$\pm$2.3 e.a to intramuscle and 1.1$\pm$2.7 e.a. to epithelial injection method. 5. Conception rate derived from E.T. was 11.1% to freezing embryos and 46.2% to fresh E.T., difference significantly(P＜0.05).

• Korean Chemical Engineering Research
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• v.40 no.6
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• pp.769-777
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• 2002

Using four components - nonionic surfactants, water, hydrocarbon oil and an alcohol as cosurfactant, 12 types of cleaning agents were prepared, and their physical properties such as surface tension, viscosity, electroconductivity and phase stability were measured. As the formulated cleaning agents have low surface tensions(30.5-31.1 dyne/cm) and low viscosities (1.6-7.2 c.p.), they are satisfied with the general physical properties of water-in-oil(W/O) microemulsions for their industrial use. They showed a tendency that their temperature range for stable one-phase microemulsion decreased in accordance with the increase of alcohol/surfactant(A/S) ratio in the formulations. However, the temperature range of one-phase microemulsion was much more affected by hydrophilic lipophillic balance(HLB) value of the nonionic surfactant which increased its temperature range and it increased in accordance with the higher HLB value in the formulations. And the maximum content of water which can keep stable one-phase W/O microemulsion was measured at each sample. In addition, their temperature range for stable one-phase microemulsion was also measured. It was confirmed that the selection of surfactant type was very important for formulating a cleaning agent, since the W/O microemulsion system with the nonionic surfactant of the lower HLB value showed better cleaning efficacy that of the higher HLB value for abietic acid as a soil, which was used for preparing a rosin-type flux. In the formulated cleaning agents with the increase of A/S ratio in the formulations, however, there was no significant difference in cleaning efficacy. It was investigated that the differences of their cleaning efficacy was affected by the change of the condition of temperature and sonicating frequency as important factors in the industrial cleaning. That is, the higher, their cleaning temperature and the lower, their sonicating frequency, the more increased, their cleaning efficacy. Furthermore, using optical instruments like UV/Visable Spectrophotometer and FT-IR Spectrometer, their cleaning efficacy for abietic acid was measured. The removal of soil from the contaminated rinse water was measured by gravity separation method in the rinse bath. As a result, the cleaning agent system having the nonionic surfactant of HLB value 6.4 showed over 85% water-oil separation efficacy at over $25^{\circ}C$. Therefore, it was demonstrated in this work that the formulating cleaning agents were very effective for cleaning and economical in the possible introduction of water recycling system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.12
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• pp.8684-8690
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• 2015

This study aimed to investigate the influence of the ankle dorsiflexion angle ($0^{\circ}$, $10^{\circ}$, and $20^{\circ}$) on the effectiveness of gastrocnemius stretching angle. The subjects of this study were 25 young man and female women. In all participants, the pennation angle of the medial head of the gastrocnemius was evaluated using ultrasonography at an ankle dorsiflexion angle of $0^{\circ}$, $10^{\circ}$, or $20^{\circ}$. Repeated measures analysis of variance was uesd to test for differences between ankle dorsiflexion angles. The independent t-test was performed to determine the significance of sex differences. The results of this study showed that the gastrocnemius pennation angle decreased as the ankle dorsiflexion angle increased, with significant interaction between each angle of ankle dorsiflexion angle (p<0.01). Sex comparison showed that the pennation angle was greater in man than in women, but the difference was not significant (p>0.05). According to the sex the gastrocnemius pennation angle is decreased as the ankle dorsiflexion angle increased (p<0.01). These results suggest that the end range of dorsiflexion is more beneficial for gastrocnemius stretching than a small range. Further studies are needed to investigate the influence of other factors, such as stretching angle and application time, on gastrocnemius stretching.

• Restorative Dentistry and Endodontics
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• v.13 no.1
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• pp.91-101
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• 1988

The purpose of this study was to evaluate Ultrasonic devices in root canal enlargement, about the effects on the canal shape and on the cutting ability beyond the curvature in curved canals. 180 resin blocks with $40^{\circ}$ curvature in apical third and 16mm long canal were made of epoxy resin and smooth broaches. These blocks were devided into six groups. According to the devices (ENAC$^{(R)}$, HARMOSONIC$^{(R)}$, Sonic Air MM 3000$^{(R)}$) and files (Zipperer file, H-file, Flexofile, K-file, Sharper file), five groups were instrumented one minute with # 15 files, then the enlarged size was measured. And # 20 files were used again in the same groups, then the enlarged size was measured. In control group, the time which was taken to enlarge the canal from # 15 to # 20 by hand technique was measured. The data was analyzed statistically. Then the enlarged shapes were evaluated in six groups with the stereomicroscope and recorded in ideal and non-ideal canal shape to compare the effects of ultrasonic devices on the canal shape. Only the ideal shaped canals were used in the study whether the cutting ability beyond the curvature in curved canals was, or not. The files with whole flutes, no flutes, and flutes in apical 5mm only were used. The weight differences of pre-and post-instrumentation by Sonic Air MM 3000$^{(R)}$ for two minutes were compared. The results were as follow: 1. Intracanal instrumentation for 1 minute with ultrasonic devices using # 15 and # 20 file in curved root canal of the epoxy resin block can not reach to the next file size. 2. Sonic Air MM 3000$^{(R)}$ shows higher cutting ability than the other two devices (p=0.001), however the percentage of non-ideal canal shape was the highest. 3. Two ultrasonic devices except Sonic Air MM 3000 considered normal in ideal canal shaping ability. 4. little cutting ability was shown beyond the curvature of curved canals.