• 소성∙가공
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• 제19권4호
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• pp.248-252
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• 2010

In this paper, three-dimensional finite element analysis of thread rolling process of a 12 point flange head bolt is conducted using a rigid-plastic finite element method based metal forming simulator AFDEX 3D. A whole sequence of cold forming processes of a long shaft bolt composed of four forging stages and final thread rolling process is simulated to reveal the mechanism of thread formation. A mesh density control function is applied near the major plastic deformation region to achieve computational efficiency. It has been shown both numerically and experimentally that longitudinal lengthening or shortening is negligible in thread rolling.

• International Journal of Aerospace System Engineering
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• 제2권2호
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• pp.54-57
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• 2015

The purpose of this paper is to provide the method of conventional stress analysis for a pressurized hydraulic cylinder with internal thread undercut. In the case of hydraulic cylinder with thread undercut, several loads and stresses occur during operating. So, the thread undercut can be most critical section has to be considered in detail for strength check. In this paper, the conventional stress analysis method at internal thread undercut of hydraulic cylinder based on Kowalski's formula is introduced. The method is verified by comparing to FEM analysis results using ANSYS.

• Journal of Acupuncture Research
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• 제36권1호
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• pp.55-58
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• 2019

The aim of this study was to investigate the efficacy of treatment with thread-embedding therapy for 24 patients with hemifacial spasm (HFS). The muscle spasm of these patients was treated with thread-embedding therapy. Patients with nuchal pain were treated with tendino-musculature acupuncture in the sternocleidomastoid, splenius, and trapezius muscles. We evaluated the treatment effect using the Scott's scale, where 20, 3, 1, and 0 patients presented Scott's grade 0, grade 1, grade 2, and grade 3, respectively. The grade of the spasm intensity decreased noticeably after treatment. The results revealed that the Scott's grade changed to 0 in 83.3% of HFS patients, and 91.7% patients felt satisfied with thread-embedding therapy. These findings suggested that thread-embedding therapy was effective and can be used widely for HFS.

• 동의생리병리학회지
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• 제31권1호
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• pp.25-35
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• 2017

About 60% to 90% of a total population experience low back pain at least once of life, and about 35% to 79% among them experience a recurrent and chronic low back pain. thread-embedding therapy is mainly used to improve appearance or treat obesity in early stage, but recently it is also used to treat musculoskeletal pain. This study aimed to search Chinese study using thread-embedding therapy on low back pain and to analyse their methodology. Three Chinese database(CNKI(www.cnki.net), WANFANG(www.wanfangdata.com), WEIPU(www.cqvip.com)) were searched for clinical study of thread-embedding therapy up to March 2016. The characteristics of included studies and regimen of thread-embedding in those studies were analyzed. The total 21 studies (4 case studies, 16 non-randomized controlled trials, 1 randomized controlled trial) were included. All studies on thread embedding treatment of low back pain reported that its effectiveness was very good. The most frequently used acupoints was Ashi acupoints and acupoints on bladder meridian(BL) or governor vessel(GV). Thread-embedding therapy is considered very useful for low back pain in Traditional Chinese medicine. Further studies are needed to investigate the effect of thread-embedding therapy and to expand its application. This study is limited in that the literature search in the Chinese database were restricted.

• 대한임베디드공학회논문지
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• 제12권4호
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• pp.205-212
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• 2017

Linux Foundation has announced a real-time kernel, called Zephyr, for IoT applications recently. Zephyr kernel provides synchronous and asynchronous IPC for data communication between threads. Synchronous IPC is useful for programming multi-threads that need to be executed synchronously, since the sender thread is blocked until the data is delivered to the receiver thread and the completion of data transfer can be known to two threads. In general, 'IPC execution time' is defined as the time duration between the sender thread sends data and the receiver thread receives the data sent. Especially, it is important that 'IPC execution time' in the synchronous IPC should be fixed in real-time kernel like Zephyr. However, we have found that the execution time of the synchronous IPC in Zephyr kernel increases in proportion to the number of threads executing in the kernel. In this paper, we propose a method to implement a fixed time synchronous IPC in Zephyr kernel using Direct Thread Switching(DTS) technique. Using the technique, the receiver thread executes directly after the sender thread sends a data during the remaining time slice of the sender thread and we can archive a fixed IPC execution time even when the number of threads executing in the kernel increases. In this paper, we implemented synchronous IPC using DTS in the Zephyr kernel and found the IPC execution time of the IPC is always 389 cycle that is relatively small and fixed.

• The Journal of Advanced Prosthodontics
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• 제7권2호
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• pp.115-121
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• 2015

PURPOSE. This study aimed to evaluate the effect of implant thread depth on primary stability in low density bone. MATERIALS AND METHODS. The insertion torque was measured by inserting Ti implants with different thread depths into solid rigid polyurethane blocks (Sawbones) with three different bone densities ($0.16g/cm^3$, $0.24g/cm^3$, and $0.32g/cm^3$). The insertion torque value was evaluated with a surgical engine. The static compressive strength was measured with a universal testing machine (UTM) and the Ti implants were aligned at $30^{\circ}$ against the loading direction of the UTM. After the static compressive strength test, the Ti implants were analyzed with a Measurescope. RESULTS. The Ti implants with deeper thread depth showed statistically higher mean insertion torque values (P<.001). Groups A and group B had similar maximum static compressive strengths, as did groups C and D (P>.05). After the static compressive strength, the thread shape of the Ti implants with deeper thread depth did not show any breakage but did show deformation of the implant body and abutment. CONCLUSION. The implants with deeper thread depth had higher mean insertion torque values but not lower compressive strength. The deep threads had a mechanical stability. Implants with deeper thread depth may increase the primary stability in areas of poor quality bone without decreasing mechanical strength.

• 한방안이비인후피부과학회지
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• 제34권1호
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• pp.1-12
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• 2021

Objectives : This study was to investigate the effectiveness of thread-embedding therapy for the treatment of acute phase of Bell's palsy. Methods : Thread-embedding therapy was performed once a week on 29 patients within 1 weeks after the onset. We investigated the general characters, Yanagihara's score, House-Brackmann scale and FDI were used to evaluate the effectiveness of thread-embedding therapy. Results : Facial muscle recovery began at 13.37th day, that was about 0.36 day earlier than the previous patients who were treated without thread-embedding therapy in 2017 at the same hospital, but there was no statistical significance. In the change of each scale before and after treatment, Yanagihara's score, House-Brackmann scale, physical function and social function of FDI were changed significantly. Compared with the patients treated without thread-embedding therapy in 2017, Yanagihara's score was a little higher and House-Brackmann scale was a little lower. Conclusions : These findings suggested that thread-embedding therapy on acute phase of Bell's palsy was a little more effective than the conventional therapy without thread-embedding therapy.

• Journal of Korean Neurosurgical Society
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• 제65권2호
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• pp.307-314
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• 2022

Objective : The percutaneous thread transection technique is a surgical dissecting method using a dissecting thread inserted through a needle under ultrasound guidance without skin incision. As the new dissecting threads were developed domestically, this cadaver study was conducted to compare the effectiveness and safety between the new threads (ultra V sswire and smartwire-01) and a pre-existing commercial dissecting thread (loop & shear) by demonstrating a modified looped thread cubital tunnel release. Methods : The percutaneous cubital tunnel release procedure was performed on 29 fresh cadaveric upper extremities. The pre-existing commercial thread was used in 5 upper extremities. The two newly developed threads were used in 24 upper extremities. Two practitioners performed the procedures separately. After the modified looped thread cubital release, anatomical and histological analyses were performed by a blinded anatomist. The presence of the dissected cubital tunnel and damaged adjacent soft tissue was assessed. Results : Out of the 29 cadaveric upper extremities, 27 specimens showed complete dissection of the Osborne ligament and the proximal fascia of the flexor carpi ulnaris muscle. One specimen was incompletely dissected in each of the ultra V sswire and smartwire-01 groups. There were no injuries of adjacent structures including the ulnar nerve, ulnar artery, medial antebrachial cutaneous nerve, or flexor tendon with either the commercial thread or the newly developed threads. The anatomical analysis revealed clear and sharp incisional margins of the cubital tunnel in the Smartwire-01 and loop & shear groups. All three kinds of threads maintained proper linear elasticity for easy handling during the procedure. The smartwire-01 provided higher visibility in ultrasound than the other threads. Conclusion : The newly developed threads were effective and safe for use in the thread cubital tunnel release procedure.

• 소성∙가공
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• 제19권3호
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• pp.160-166
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• 2010

In this paper, the process parameters of thread rolling were designed based on the numerical analysis results. Firstly, the effective analysis conditions that guarantee the reliability of the analysis results were found. To find the effective analysis conditions, the analyses were carried out for various numbers of teeth. And then, the effects of the process parameters such as tool shape and temperature on the thread rolling performance were investigated. The formability in thread rolling process was evaluated in terms of Cockcroft-Latham damage value. In order to evaluate formability, Cockcroft-Latham damage value was normalized by the critical damage value which was obtained from the analysis of uniaxial tensile test. The analyses were carried out using DEFORM-3D. The results showed that the flank angle and crest round had an effect on the thread rolling load. It was also shown that temperature had significant effects on the effective strain distribution, rolling load, and damage. With the reduced formability of stainless steel at higher temperature, it was shown that the normalized damage values increased as the process temperature.

• 한방안이비인후피부과학회지
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• 제28권1호
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• pp.119-133
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• 2015

Objective : Thread embedding acupuncture has become popular as a minimally invasive treatment for facial wrinkles and laxity. However, there is little published clinical practice guidelines. This study is to developing a specific procedure of thread embedding acupuncture for facial wrinkles and laxity. Method : We reviewed and summarized 6 studies on thread embedding acupuncture for facial wrinkles and laxity. And, four practitioners who have more than four year of clinical experience and one hundred of cases were participated in developing a thread embedding acupuncture procedure for facial wrinkles and laxity. Result and conclusion : We developed a thread embedding acupuncture procedure for facial wrinkles and laxity which consists of correction of lower jaw, facial laxity, nasolabial fold and eye wrinkles.