• Korean Journal of Audiology
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• v.23 no.4
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• pp.204-209
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• 2019

For a minimally invasive approach to access the facial nerve, we designed an extended epitympanotomy via a transmastoid approach that has proven useful in cases of traumatic facial nerve palsy and pre-cholesteatoma. To evaluate the surgical exposure through an extended epitympanotomy, six patients with traumatic facial nerve palsy were enrolled in this study. The same surgical technique was used in all patients. Patients were assessed and the degree of facial nerve paralysis was determined prior to surgery, 1-week post-operatively, and 6-months post-operatively using the House-Brackmann grading system. In all cases, surgical exposure was adequate. All patients with traumatic facial nerve palsy were male and the age range was 13 to 83 years. In all cases, the location of the facial nerve damage was limited to the area between the first and second genu. Symptoms of all the patients improved by 6 months post-operation (p=0.024). There were no complications in any of the patients. Extended epitympanotomy is useful for safe, rapid surgical exposure of the attic area, sparing the patient post-operative dimpling, skin incision complications, and lengthy exposure to anesthesia. We suggest that surgery for patients with facial nerve palsy secondary to trauma be performed using this described technique.

• Korean Journal of Head & Neck Oncology
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• v.26 no.2
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• pp.221-224
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• 2010

Papillary thyroid carcinoma frequently invades the lymph node, trachea, esophagus and perithyroid tissue. However, direct extension to posterior pharyngeal area is known to be rare. A 64-year-old male was referred to our clinic presenting as posterior pharyngeal mass during gastrofiberscopy. The neck CT scan showed soft tissue mass in retropharynx and lymph node in right level III with calcifications. We performed the total thyroidectomy with selective(level II, III, IV) and anterior compartment neck dissection. In operative findings, the right thyroid mass were connected to the retropharynx through the posterior portion of inferior constrictor muscle. Histopathologic findings revealed the papillary thyroid carcinoma extended to retropharynx. We report a unique case with a literature review.

• Journal of Soil and Groundwater Environment
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• v.18 no.2
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• pp.45-53
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• 2013

Many cases of strategically designed groundwater remediation have lack of information of hydraulic conductivity or permeability, which can render remediation methods inefficient. Many studies have been carried out to minimize this shortcoming by determining detailed hydraulic information either through direct or indirect measurements. One popular method for hydraulic characterization is the pilot point method (PPM), where the hydraulic property is estimated at a small number of strategically selected points using secondary measurements such as hydraulic head or tracer concentration. This paper adopted a D-optimality based pilot point method (DBM) developed previously for hydraulic head measurements and extended it to include both hydraulic head and tracer measurements. Based on different combinations of trials, our analysis showed that DBM performs well when hydraulic head is used for pilot point selection and both hydraulic head and tracer measurements are used for determining the conductivity values.

• 한국방재학회:학술대회논문집
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• 2009.02b
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• pp.134.1-134.1
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• 2009

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.5
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• pp.81-87
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• 2006

In this paper, an experimental optical head tracker system is designed and constructed. The system is composed of the infrared LEDs and two infrared CCD cameras to filter out the interference of another light in the limited environment like the cockpit. Then the optical head tracker algorithm is designed by using the feature detection algorithm and the 3D motion estimation algorithm. The feature detection algorithm, used to obtain the 2D position coordinates of the features on the image plane, is implemented by using the thresholding and the masking techniques. The 3D motion estimation algorithm which estimates the motion of a pilot's head is implemented by using the extended Kalman filter (EKF). Also, we used the precise rate table to verify the performance of the experimental optical head tracker system and compared the rotational performance of this system with the inertial sensor.

• Anatomy and Cell Biology
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• v.56 no.1
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• pp.39-45
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• 2023

Fixation of radial head fracture with minimally invasive posterior approach remains a significant challenge. The aim of this study was to determine the feasibility of trans-anconeus posterior elbow approach and to observe lateral ulnar collateral ligament (LUCL) in extended elbows. This cadaveric study was performed in twenty upper limbs of fresh fixed adult male cadavers. An oblique incision was made in the middle segment of anconeus until the lateral ligament complex and the joint capsule had been revealed. A deep dissection was explored to observe the anatomical relationship of the LUCL to the anconeus. Measurements of the LUCL were recorded while the elbow was fully extended. The mean distance between the edge of the radial head and the proximal insertion of the LUCL was 13.3 mm (11.5-16.2 mm); the mean distance between the edge of the radial head and the distal insertion of the LUCL was 20.9 mm (19.2-23.4 mm); the distance between the edge of the radial head and the distal edge of the annular ligament was 11.2 mm (8.22-11.7 mm). By estimate correlation of the previous measurements, the direct and accessible way to expose the posterolateral articular capsule of the elbow joint was through a window in medial 2/3 of the middle segment of anconeus muscle. These trans-anconeus approach is useful. It provides good visualization, facilitates applying the implants, and lessens the risk of radial nerve injury. Awareness of the anatomy is mandatory to avoid injury of LUCL.

• Korean Journal of Head & Neck Oncology
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• v.16 no.1
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• pp.33-36
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• 2000

Objectives: Angiocentric T-cell lymphoma of the head and neck is an angiocentric and angiodestructive lymphoreticular proliferative disorder. It has been treated with various treatment modalities, but its prognosis is poor and the treatment modality is controversial. We performed this study to suggest a treatment modality with improved results. Materials and Methods: We studied 40 cases of pathologically confirmed angiocentric T-cell lymphoma from July 1984 to December 1996, 35 cases of which showed complete response after initial treatment. All the patients were divided into two groups according to treatment modality. 15 cases received radiotherapy alone (Group I) and 20 cases received radiotherapy after five cycles of CHOP-Bleo chemotherapy(Group II). We analyzed the subsites of tumor, stage, treatment modality and treatment outcome and causes of failure for each group, and compared the three-year no evidence of disease(NED) between the two groups. Results: The three-year NED of a combined chemoradiotherapy was higher than that of a radiotherapy alone (p=0.0478). The three-year NED according to groups and stage were as follows: Group I=6/15(40.0%), stage IE=5/10(50.0%), stage IIE=1/5(20%), Group II=13/20(65.0%), stage IE=9/13(69.2%), stage IIE=4/7(57.1%). Radiotherapy alone is not well effective for the nasal cavity lymphoma extended to paranasal sinus and the palate. Conclusion: We are unable to provide clear guidelines for treatment, but recommend the initial treatment with oral alkylating agents and steroids followed by radiotherapy for Ann Arbor stage II tumors and stage I of the palate lymphoma and the nasal cavity lymphoma extended to paranasal sinus.

• Korean Journal of Head & Neck Oncology
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• v.15 no.2
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• pp.239-242
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• 1999

Spindle cell carcinomas of the head and neck are unusual neoplasms that are histologically biphasic, having both squamous cell carcinoma and apparently malignant spindle cell or sarcomatous element. Controversy about the histogenesis of these tumors has resulted in various terminology ; sarcomatoid carcinoma, pseudosarcoma, carcinosarcoma, and spindle cell carcinoma. The clinical course and natural history of these tumors are also variable. We report a case of 64-year-old male who complained of a neck mass. The patient was treated with extended radical neck dissection and postoperative radiotherapy, but the primary site of spindle cell carcinoma could not be found. We reviewed the clinical course, treatment, prognosis, and histogenesis of spindle cell carcinoma of the head and neck.

• Journal of Biosystems Engineering
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• v.19 no.4
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• pp.329-342
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• 1994

In order to reduce the production cost and improve the quality of dairy feed, several dairy feed mill models suitable for Korean farm size were developed. 6 TMR models were developed for the 1000, 600, 200 head of dairy cattle, and evaluated for capital investments and production costs to suggest the best model. Followings are summary of this study : 1. TMR terminal models were designed that dairy production capacity of TMR1000 models are 40 ton/day, TMR600 model is 20 ton/day and TMR200 models are 10 ton/day. Also, they can be extended their capacity up to twice. 2. Capital investment of TMR terminal models is 145 million won for TMR200-1,205 million won for TMR600 and 609 million won for TMR1000-3 model. 3. The bigger TMR terminal model has the more advantage in production cost. The best model for 1000 head of dairy cattle farm was TMR1000-3 with 10,849 won/ton of production cost, TMR600 for 600 head of dairy cattle farm with 13,829 won/ton, TMR200-1 for 200 head of dairy cattle farm with 16,943 won/ton of production cost, so feed production cost for the 200 head farm was 50% higher than 1,000 head size farm.

• Journal of Internet Computing and Services
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• v.10 no.3
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• pp.61-69
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• 2009

Most existing clustering protocols have been aimed to provide balancing the residual energy of each node and maximizing life-time of wireless sensor networks. In this paper, we present the threshold based cluster head replacement strategy for clustering protocols in wireless sensor networks. This protocol minimizes the number of cluster head selection by preventing the cluster head replacement up to the threshold of residual energy. Reducing the amount of head selection and replacement cost, the life-time of the entire networks can be extended compared with the existing clustering protocols. Our simulation results show that our protocol outperformed than LEACH in terms of balancing energy consumption and network life-time.