• Journal of Chest Surgery
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• v.33 no.12
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• pp.963-967
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• 2000

정상심실중격의 폐동맥협착은 흔한 선천성 심장질환이지만 신생아기에 심한 증세를 보이는 위기적 폐동맥 협착은 드물며 예후도 대단히 나쁘다. 경피적 풍선 판막성형술의 발달과 함께 폐동맥협착의 외과적 치료는 더욱 줄어드는 추세이다. 본 증례는 정상심실중격의 위기적 폐동맥협착증으로 진단받은 생후 2일된 남자 신생아로 심한 청색증과 저산소증을 보여 응급실로 내원하였다. 환아는 산소공급 및 Prostaglandin E$_1$을 투여 후 동맥혈 산소 분압이 19 mmHg에서 54mmHg로 증가하였다. 경피적 풍선 판막성형술을 시도하였으나 유도도관(Guide wire)이 판막의 개구부를 통과하지 못하였고 시술도중 심낭내로 조영제가 고이는 소견을 보여 우심실 천공이 의심되었으므로 응급으로 정상체온의 체외순환하에서 폐동맥 절개후 폐동맥 판막절개술을 시행하였다. 수술 후 중환자실에서의 수술경과는 양호하였고 현재 수술 6개월째 외래 추적관찰중이다.

• Design & Manufacturing
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• v.13 no.1
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• pp.55-60
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• 2019

Smart-phone in the recently released high-end applied to the camera module is equipped with the most features auto focusing camera module. Also, auto focusing camera module is divided into voice coil motor, encoder, and piezo according to type of motion mechanism. Auto focusing camera module is composed of voice coil motor (VCM) as an actuator and leaf spring as a guide and suspension. VCM actuator is made of magnet, yoke as a metal, and coil as a copper wire. Recently, the assembly as yoke and magnet is made by human resources. These process has a long process time and it is difficult to secure quality. Also, These process is not economical in cost, and productivity is reduced. Therefore, an automatic assembly as yoke and magnet is needed in the present process. In this paper, we have developed an automatic assembly device that can automatically assemble yoke and magnet, and performed verifying performance. Therefore, by using the developed automatic assembly device, it is possible to increase the productivity and reduce the production cost.

• Journal of The Korean Society of Emergency Medicine
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• v.29 no.6
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• pp.636-640
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• 2018

Objective: Central venous catheter (CVC) misplacement can result in incorrect readings of the central venous pressure, vascular erosion, and intravascular thrombosis. Several studies have examined the correlation between the guidewire J-tip direction and misplacement rate. This study examined whether the guidewire J-tip direction (cephalad vs. caudad) affects the misplacement rate in right subclavian venous catheterization. Methods: This prospective randomized controlled study was conducted between February 2016 and February 2017. The subjects were divided into two groups (cephalad group vs. caudad group) and the misplacement rate was compared according to guidewire J-tip direction in each group. Results: Of 100 patients, the cephalad and caudad groups contained 50 patients each. The age, sex, and operator experience were similar in the two groups. In the cephalad group, misplacement of CVC insertion into the ipsilateral internal jugular vein occurred in two cases. In the caudad group, misplacement of CVC insertion into the contralateral subclavian vein occurred in one case, with loop formation in the brachiocephalic trunk in one case. Guidewire J-tip direction showed no significant correlation with CVC misplacement. Conclusion: The guidewire J-tip direction does not influence the rate of misplacement.

• Journal of the Semiconductor & Display Technology
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• v.17 no.4
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• pp.42-45
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• 2018

As The semiconductor decrease from 10 nanometer to 7 nanometer, It is suggested that "More than Moore" is needed to follow Moore's Law, which has been a guide for the semiconductor industry. Fan-Out Wafer Level Package(FOWLP) is considered as the key to "More than Moore" to lead the next generation in semiconductors, and the reasons are as follows. the fan-out WLP does not require a substrate, unlike conventional wire bonding and flip-chip bonding packages. As a result, the thickness of the package reduces, and the interconnection becomes shorter. It is easy to increase the number of I / Os and apply it to the multi-layered 3D package. However, FOWLP has many issues that need to be resolved in order for mass production to become feasible. One of the most critical problem is the warpage problem in a process. Due to the nature of the FOWLP structure, the RDL is wired to multiple layers. The warpage problem arises when a new RDL layer is created. It occurs because the solder ball reflow process is exposed to high temperatures for long periods of time, which may cause cracks inside the package. For this reason, we have studied warpage in the FOWLP structure using commercial simulation software through the implementation of the reflow process. Simulation was performed to reproduce the experiment of products of molding compound company. Young's modulus and poisson's ratio were found to be influenced by the order of influence of the factors affecting the distortion. We confirmed that the lower young's modulus and poisson's ratio, the lower warpage.

• Journal of Trauma and Injury
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• v.34 no.2
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• pp.130-135
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• 2021

Celiac artery compression is a rare condition in which the celiac artery is compressed by the median arcuate ligament. Case reports of compression after trauma are hard to find. Blunt traumatic pericardium rupture is also a rare condition. We report a single patient who experienced both rare conditions from a single blunt injury. An 18-year-old woman was brought to the trauma center after a fatal motorcycle accident, in which she was a passenger. The driver was found dead. Her vital signs were stable, but she complained of mild abdominal pain, chest wall pain, and severe back pain. There were no definite neurologic deficits. Her initial computed tomography (CT) scan revealed multiple rib fractures, moderate lung contusions with hemothorax, moderate liver injury, and severe lumbar spine fracture and dislocation. She was brought to the angiography room to check for active bleeding in the liver, which was not apparent. However, the guide wire was not able to pass through the celiac trunk. A review of the initial CT revealed kinking of the celiac trunk, which was assumed to be due to altered anatomy of the median arcuate ligament caused by spine fractures. Immediate fixation of the vertebrae was performed. During recovery, her hemothorax remained loculated. Suspecting empyema, thoracotomy was performed at 3 weeks after admission, revealing organized hematoma without pus formation, as well as rupture of the pericardium, which was immediately sutured, and decortication was carried out. Five weeks after admission, she had recovered without complications and was discharged home.

• Clinics in Shoulder and Elbow
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• v.13 no.1
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• pp.72-78
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• 2010

Purpose: Too develop a flexible drill device that can be inserted into the shoulder joint so that arthroscopic transosseous suture repair for Bankart lesion is possible. Materials and Methods: We created a device composed of a flexible drill unit and a guide pipe unit. The flexible drill unit was made of flexible multifilament wires (1.2 mm in diameter) that was twisted into one cord so that it can flex in any direction and a drill bit (1.2 mm in diameter) that is attached onto one end of the flexible wire. The guide pipe unit was a 150 mm long metal pipe (2.0 mm in inner diameter and 3.0 mm in outer diameter), with one end bent to 30 degrees. The flexible drill set was inserted into the shoulder joint through the posterior portal of the joint. The guide pipe component was placed onto the medial wall of the glenoid so that the pipe was placed 5 mm posterior to the margin of the anterior glenoid rim. The flexible drill was driven through the glenoid by the power drill so that holes were made in the glenoid. A non- absorbable suture was passed through the hole. Tying of a sliding knot tying was accomplished over the capsule and labrum after making a stitch through the capsule and labrum with a suture hook loaded with suture passer. The same procedures were done at the 2 and 4 O'Clock positions of the glenoid. Results: Five cases with Bankart lesion received arthroscopic transosseous repair with our flexible drill device. There were no intraoperative problems. Neither redislocation nor subluxation was reported at final follow-up. Conclusion: Arthroscopic transosseous suture repair without suture anchors and easy tying of a sliding knot are possible with a flexible drill set.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.16 no.3
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• pp.247-258
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• 1994

We got this conclusion from an investigation about complications from 144 cases of 130 patients who were to be searched their personal records, admission chart, clinical laboratory sheet, anesthetic record, consult sheet and radiographic opinion. They had orthognathic surgery for maxillofacial deformity treatment at the department of oral and maxillofacial surgery in dental school of Kyung Hee university for 4 years and 10 months, from March 1989 to December 1993. 1. In the intraoperative phase, by the frequency of complication, blood vessel injury was found the most-22%, and then soft tissue injury, unfavorable osteotomy split, and there were some cases of tooth injury and inappropriate osteotomy. In the mandibular segmental osteotomy, blood vessel injury was found the most frequently-20 cases (27%), soft tissue injury, unfavorable osteotomy split were the second frequent cases, and then unfavorable fragment position was found. In the extraoral vertical ramus osteotomy and Le Fort I osteotomy also, blood vessel injury and nerve injury were found the most. 2. In the postoperative hospitalization phase, by the frequency of complication, hematoma (23%) was happened the most, except for that, lkie the complication that can be happened by adverse reaction of medicine or long hospital life. In the case of SSRO, there were 21 cases (20%) of hematoma, and this wal the most frequently case. In the case of EVRO, hematoma wasn't happened that much-2 case (4%). 3. In the follow up phase, relaps, numbness and TMJ dysfunction were happened. In mandibular surgery, the forward relapse percentage of point B, was 27% when used wire fixation on SSRO, was 15% by miniplate fixation on SSRO and was 7% on EVRO. In the case of SSRO, numbness was kind of high, comparing to ordinary surgery-12 cases(16 There were many difficulties in analyzing this data accurately, Although orthognathic surgery is done many times, only available date is from the "success" stories and data is not consistently recorded for the cases with complications. In this manner, much essential informantion is lost and overlooked. When data is charted including those cases that are seemingly insignificalt, we can have a much clearer understanding and more accurate guide on treatment protocols.

• Korean Journal of Environmental Biology
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• v.34 no.3
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• pp.183-192
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• 2016

Silver nanomaterials have been intensively applied in consumer products of diverse industrial sectors because of their strong biocidal properties and reported to be hazardous to aquatic organisms once released in the environment. Nanomaterials including sliver, are known to be different in toxicity according to their physicochemical characteristics such as size, shape, length etc. However studies comparing toxicity among silver nanomaterials with different physicochemical characteristics are very limited. Here, toxicities of silver nanomaterials with different size (50, 100, 150 nm), length (10, $20{\mu}m$), shape (wire, sphere), and coating material (polyvinylpyrrolidone, citrate) using OECD test guidelines were evaluated in aquatic species (zebrafish, daphnia, algae) and compared. On a size property, the smaller of silver nanomaterials, the more toxic to tested organisms. Sphered type of silver nanomaterials was less toxic to organisms than wired type, and shorter nanowires were less toxic than longer ones. Meanwhile the toxic effects of materials coated on silver nanomaterials were slightly different in each tested species, but not statistically significant. To the best of our knowledge, it is first investigation to evaluate and compare ecotoxicity of silver nanomaterials having different physicochemical characteristics using same test species and test guidelines. This study can provide valuable information for human and environmental risk assessment of silver nanomaterials and guide material manufacturers to synthesize silver nanomaterials more safely to human and environment.

• Journal of the Korean Arthroscopy Society
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• v.13 no.2
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• pp.183-187
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• 2009

Purpose: We describe a new and simple technique for arthroscopic fixation of tibial intercondylar eminence avulsion fracture using bioabsorbable pins in skeletally immature patients. Operative Technique: Diagnostic knee arthroscopy is performed using anterolateral and anteromedial portals. Fracture debris and blood clot are debrided to expose the injured site well. The fragment is reduced with the probe and fixed temporarily with a 1.1-mm diameter K-wire that is inserted percutaneously from the anterosuperior aspect of the knee joint. The drill guide is introduced into the joint and the fragment is secured by bioabsorbable, poly-p-dioxanone 1.3-mm pins inserted from different angles. The pins are 40 mm in length. The knee is placed in a long leg cast in extension for 4 weeks to assure that full extension is obtained. Conclusion: Arthroscopic fixation of an tibial intercondylar eminence avulsion fracture using bioabsorbable pins is not a technically demanding, suitable method that ensures fracture healing and restores the stability of the joint.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.1
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• pp.109-115
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• 2019

In arc-welding applying to the present automobile part manufacturing process, a wrist-hollow type arc welding robot can shorten the welding cycle time, because feedability of a welding wire is not affected by a robot posture and thus facilitates high-quality arc welding, based on stable feeding with no entanglement. In this paper, we will propose the optimization of wrist design for a wrist-hollow type 6-Axis articulated robot. Specifically, we will perform the investigation on the optimized design of inner diameter of hollow arms (Axis 4 and Axis 6) and width of the upper arm by using the simulation of robot motion characteristics, using a Genetic Algorithm (i.e., GA). Our simulations are based on $SolidWorks^{(R)}$ for robot modeling, $MATLAB^{(R)}$ for GA optimization, and $RecurDyn^{(R)}$ for analyzing dynamic characteristics of a robot. Especially $RecurDyn^{(R)}$ is incorporated in the GA module of $MATLAB^{(R)}$ for the optimization process. The results of the simulations will be verified by using $RecurDyn^{(R)}$ to show that the driving torque of each axis of the writs-hollow 6-axis robot with the optimized wrist design should be smaller than the rated output torque of each joint servomotor. Our paper will be a guide for improving the wrist-hollow design by optimizing the wrist shape at a detail design stage when the driving torque of each joint for the wrist-hollow 6-axis robot (to being developed) is not matched with the servomotor specifications.