• Journal of Astronomy and Space Sciences
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• 제35권3호
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• pp.119-131
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• 2018

In spite of a short history of only 30 years in space development, Korea has achieved outstanding space development capabilities, and became the $11^{th}$ member of the "Space Club" in 2013 by launching its own satellites with its own launch vehicle from a local space center. With the successful development and operation of more than 10 earth-orbiting satellites since 1999, Korea is now rapidly expanding its own aspirations to outer space exploration. Unlike earth-orbiting missions, planetary missions are more demanding of well-rounded technological capabilities, specifically trajectory design, analysis, and navigation. Because of the importance of relevant technologies, the Korean astronautical society devoted significant efforts to secure these basic technologies from the early 2000s. This paper revisits the numerous efforts conducted to date, specifically regarding flight dynamics and navigation technology, to prepare for future upcoming planetary missions in Korea. However, sustained efforts are still required to realize such challenging planetary missions, and efforts to date will significantly advance the relevant Korean technological capabilities.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제16권3호
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• pp.190-194
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• 2013

Internal hernia (IH) is a rare cause of small bowel obstruction occurs when there is protrusion of an internal organ into a retroperitoneal fossa or a foramen in the abdominal cavity. IH can be presented with acute or chronic abdominal symptom and discovered by accident in operation field. However, various kinds of imaging modalities often do not provide the assistance to diagnose IH preoperatively, but computed tomography (CT) scan has a high diagnostic accuracy. We report a case of congenital IH in a 6-year-old boy who experienced life threatening shock. CT scan showed large amount of ascites, bowel wall thickening with poor or absent enhancement of the strangulated bowel segment. Surgical exploration was performed immediately and had to undergo over two meters excision of strangulated small bowel. To prevent the delay in the diagnosis of IH, we should early use of the CT scan and take urgent operation.

• JSTS:Journal of Semiconductor Technology and Science
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• 제16권3호
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• pp.300-311
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• 2016

The analog-to-digital-converter-based (ADC-based) backplane receivers that consist of a front-end ADC followed by a digital equalizer are gaining more popularity in recent years, as they support more sophisticated equalization required for high data rates, scale better with fabrication technology, and are more immune to PVT variations. Unfortunately, designing an ADC-based receiver that meets tight power and performance budgets of high-speed backplane link systems is non-trivial as both front-end ADC and digital equalizer can be power consuming and complex when running at high speed. This paper reviews the state of art designs for the front-end ADC and digital equalizers to suggest implementation choices that can achieve high speed while maintaining low power consumption and complexity. Design-space exploration using system-level models of the ADC-based receiver allows through analysis on the impact of design parameters, providing useful information in optimizing the power and performance of the receiver at the early stage of design. The system-level simulation results with newer device parameters reveal that, although the power consumption of the ADC-based receiver may not comparable to the receivers with analog equalizers yet, they will become more attractive as the fabrication technology continues to scale as power consumption of digital equalizer scales well with process.

• Advances in pediatric surgery
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• 제13권2호
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• pp.222-227
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• 2007

A differential diagnosis between the true hermaphroditism (TH) and mixed gonadal dysgenesis (MGD) has important clinical implications for gender assignment and the decision for early gonadectomy; however, variable clinical and histological features frequently lead to the confusion of TH with MGD. A 17-month-old boy was presented with proximal hypospadias with chordee and right non-palpable testis in his scrotum. He also had right auricular anomaly including a separated tragus with skin tag. Left testis was well palpable in his left scrotum. Diagnostic right inguinal exploration showed Mullerian structures such as a gonad like an ovary and a fallopian tube with a uterus, which were removed. Repair of hypospadias and right auricular anomaly was also done. Following ultrasonography (USG) showed a normal looking testis in left scrotum. His chromosome was 45, XO/46, XY. We report a difficult case of mixed gonadal dysgenesis mimicking true hermaphroditism which combines ipsilateral congenital auricular anomaly.

• 아동학회지
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• 제32권1호
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• pp.1-11
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• 2011

This aim of this study was to investigate the effects of the music appreciation teaching-learning method on the musical ability of young children. The music appreciation activities were developed firstly in consideration of the 4 steps of the learning cycle (recognition, exploration, inquiry, application). One group was then taught music appreciation, taking into account the learning cycle. The results were then compared with another comparative group in terms of musical ability. The results indicated that the musical ability sum of the treatment groups improved more than the comparative group. More specifically, the treatment group for four-year-olds was seen to have improved significantly more than the comparative group in terms of musical ability. These results indicate that this music appreciation teaching-learning method has a number of positive effects upon young children`s musical ability. Therefore, it is suggested that kindergarten teachers conduct instruction with an appropriate accompanying learning cycle as part of the teaching-learning method when it comes to improving the musical ability of young children.

• Journal of Korean Neurosurgical Society
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• 제29권3호
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• pp.411-419
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• 2000

Hematomyelia is an extremely rare condition that cause severe neurological symptoms. We reported 4 cases of spontaneous hematomyelia, two cases of cavernous angioma and two cases of hematoma. In all patients, the clinical course was progressive ; motor and sensory abnormalities below the lesion and voiding difficulties were the common presenting symptom complex. The preoperative diagnosis was made by magnetic resonance imaging and the all patients underwent surgical exploration. Complete removal of hematoma was done in 3 patients and complete evacuation after aspiration of hematoma were performed in one patients. Neurological function did not worsen postoperatively in any patients. The early diagnosis with magnetic resonance imaging and immediate surgical treatment of the hematoma and the associated vascular malformation are considered to be the best way to halt the progression of the disease.

• 대한두개안면성형외과학회지
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• 제14권1호
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• pp.46-49
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• 2013

Facial deformity after nerve injury changes ones' social life. We experienced a few patients with healthy early recovery of muscle contraction after the operation with soft tissue wraparound splint. Under general anesthesia, exploration to find as many injured nerve stumps with ${\times}2.5$ loopes was undertaken at first. Interfascicular repair was done with minimal tension by 10-0 nylon under a microscope, and the suture site was sealed by approximating the surrounding fat flaps. This conjoined adipose tissue flap was a splint as a wraparound environment to reduce the tension in the coaptation site, and to increase the relative concentration of releasing neurotrophic factors by surrounding it. A 45-year-old man fell down in a drunken state and had deep laceration by broken flowerpot fragments with facial muscle weakness on the right cheek. His injured mandibular branches of the facial nerve were found. A 31-year-old female suffered from motionlessnesss of frontalis muscle after a traffic accident. She had four frontal branches injured. The man had his cheek with motion after seven days, and the woman two months after the operation. The nerve conduction test of the woman showed normalized values. Facial nerve repair surrounded by adipose tissue wraparound splint can make the recovery time relatively short.

• 지구물리
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• 제9권3호
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• pp.273-286
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• 2006

The Kyongsang Basin is the most representative Cretaceous basin in the Korean Peninsula where extensive crustal deformation and non-marine sedimentation took place in the early Cretaceous period. The lithology of the basement of the basin and adjacent areas is comprised of mainly Precambrian gneiss complex and Mesozoic granite intrusions. We have carried out magnetotelluric (MT) surveys to investigate the deep geoelectric structure around the Kyongsang Basin. The MT data were collected in the frequency range from 0.00042 to 320 Hz at 24 sites along a profile across the northern part of Kyongsang Basin. The results of MT inversion show that the thickness of sediments is estimated about 3 km to 9 km and the depth to base of granite intrusion is about 20 km. A remarkable discovery in this study is the highly conductive layer beneath the basin, having the resistivity of 1 ohm-m to 30 ohm-m and the thickness of about 3 km to 4 km or more. Although we are not able to reveal the nature of this layer, the result of this study could provide some basic information with respect to the formation process and deposit environment of the proto-Kyongsang Basin.

• 대한두개안면성형외과학회지
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• 제19권4호
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• pp.300-303
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• 2018

Intraorbital wooden foreign bodies may present difficulties in diagnosis due to their radiolucent nature. Delayed recognition and management can cause significant complications. We present a case report that demonstrates these problems and the sequela that can follow. A 56-year-old man presented with a 3-cm laceration in the right upper eyelid, sustained by a slipping accident. After computed tomography (CT) scanning and ophthalmology consultation, which revealed no fractures and suggested only pneumophthalmos, the wound was repaired by a plastic surgery resident. Ten days later, the patient's eyelid displayed signs of infection including pus discharge. Antibiotics and revisional repair failed to solve the infection. Nearly 2 months after the initial repair, a CT scan revealed a large wooden fragment in the superomedial orbit. Surgical exploration successfully removed the foreign body and inflamed pocket, and the patient healed uneventfully. However, the prolonged intraorbital infection had caused irreversible damage to the superior rectus muscle, with upgaze diplopia persisting 1 year after surgery and only minimal muscle function remaining. We report this case to warn clinicians of the difficulties in early diagnosis of intraorbital wooden foreign bodies and the grave prognosis of delayed management.

• Journal of Korean Neurosurgical Society
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• 제62권1호
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• pp.90-95
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• 2019

Objective : Anomalous muscles of the wrist are infrequently encountered during carpal tunnel surgery. Anatomic variants of the palmaris longus (PL), flexor digitorum superficialis, lumbricalis and abductor digiti minimi (ADM) have been reported but are usually clinically insignificant. Anomalies of the wrist muscles, encountered during endoscopic carpal tunnel surgery have rarely been described. I conducted this study to evaluate muscular anomalies of the volar aspect of the wrist, encountered during endoscopic carpal tunnel surgery. Methods : I studied a consecutive series of 1235 hands in 809 patients with carpal tunnel syndrome who underwent single-portal endoscopic carpal tunnel release (ECTR) from 2002 to 2014. Nine hundred seventy-three hands in 644 patients who had minimal 6-month postoperative follow-up were included in the study. The postoperative surgical outcome was assessed at least 6 months after surgery. Results : In eight patients, anomalous muscles were found under the antebrachial fascia at the proximal wrist crease and superficial to the ulnar bursa, passing superficial to the transverse carpal ligament. Those anomalous muscles were presumed to be variants of the PL or accessory ADM muscle, necessitating splitting and retraction to enter the carpal tunnel during the ECTR procedure. Other muscle anomalies were not seen within the carpal tunnel on the endoscopic view. The surgical outcome for all eight wrists was successful at the 6-month postoperative follow-up. Conclusion : Carpal tunnel surgeons, especially those using an endoscope should be familiar with unusual findings of anomalous muscles of the wrist because early recognition of those muscles can contribute to avoiding unnecessary surgical exploration and unsuccessful surgical outcomes.