• Korean Journal of Head & Neck Oncology
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• v.35 no.2
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• pp.11-17
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• 2019

Background/Objectives: Papillary thyroid carcinoma (PTC) has generally an indolent character with a good prognosis. However, recurrence remains a major concern for the patients during their lifetime. Despite the slowly progressing character of PTC, recurrence can occur within a short period after initial surgery. This study aimed to determine the clinical findings and cause of recurrence in patients who underwent re-operative surgery due to neck node recurrence by reviewing the CT (computed tomographic) scan imaging of the recurrence of PTC retrospectively. Materials & Methods: We reviewed the medical records of patients referred to Ajou University Hospital from January 2002 to January 2018. All patients had re-operative surgery due to neck node recurrence and CT scan results of preoperative evaluation and postoperative follow up. Over this period, 110 patients who underwent re-operation due to neck node recurrence with a CT scan were included in our cohort, resulting in a total of 220 re-operations. Results: The time from initial operation to first re-operation was examined in 110 patients. The median time to re-operation was 28 months, with a range of 4 months to 186 months. Most re-operations (82.7%) occurred within the first five years, 43.6% were in the first two years from the initial surgery. The result of the retrospective CT review showed newly developed cases (21,19.1%), missed diagnosis cases (42,38.2%), real recur cases after surgery (33,30.0%), and remnant lymph nodes (LNs) cases (14,12.7%). We further sub-analyzed 14 cases with remnant LNs. Reasons for remnant LNs included insufficient operation (N=5) and beyond general surgical extent. (N=9). Conclusion: Re-operation due to cervical lymph node recurrence is mostly a persistent disease. They included a missed diagnosis and incomplete operation. These finding may reduce the reoperation of cervical lymph node recurrence by accurate preoperative evaluation and complete surgical resection at the initial surgery.

• Environmental Analysis Health and Toxicology
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• v.6 no.1_2
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• pp.71-82
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• 1991

Rat embryos were cultured out of the mother from the head-fold stages, 9.5 days to 11.5 days during which they start to develop the brain, eyes, ears and cardiovascular system etc. We principally did the basic experiment in order to establish the best condition of the rat whole embryo culture in our laboratory. The temperature in the culture system was maintained 37$^{\circ}C$$\pm$0.2$^{\circ}C$ for 48 hrs. The culture was carried out in humidified atmosphere of the air, intially, the bottles were equilibrated with 5% $O_2$,5% $CO_2$, and 90% $N_2$gas mixture. After 22 or 24 and 29 or 30 hrs the cultures were reequilibrated with 20% $O_2$, 5% $CO_2$,75% $N_2$and 40% $O_2$, 5% $CO_2$, 55%$N_2$respectively. Various types of sera were tested and for the purpose of minimizing the quantity of rat serum, artificial medium was also tried and it was determined that rat serum supported normal growth over a period of 48 hrs, based on total growth analysis and structural comparisons with in vivo specimens.

• Journal of the HCI Society of Korea
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• v.7 no.2
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• pp.25-34
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• 2012

A veterinary student learns and experiences veterinary processes though experiments and practices using real animals. However, animal protection laws regulate animal experiments and restrict number of the experiments on laboratory animals, veterinary students would have less chances of the experiments and the practices for their veterinary training with real animals. This paper proposes a simulator for veterinary education based on augmented reality (AR). We selected an intravenous injection procedure for the simulation because the injection procedure is the most frequently used procedure during veterinary training and the most difficult stage for beginning veterinary students. The proposed AR simulator provides with a tangible prop, of which shape looks like a leg of a real dog. It also has a injection simulator, which receives user's input and sends force feedbacks to indicate results of the injection simulation. We developed a WorkBench type AR system with an LED display and cameras for visual information processing. Finally, we evaluated its performance through experiments and user studies to check its acceptance level and usability of the proposed system. We compared the proposed system with a traditional video based education and an AR based system using a head mounded display (HMD). The results that the proposed system showed better performances over these systems.

• Radiation Oncology Journal
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• v.3 no.2
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• pp.113-121
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• 1985

This is a retrospective analysis of 54 patients with stage I or II Non-Hodgkin's lymphoma involving the head and neck region treated with curative radiotherapy in the Department of Therapeutic Radiology, Seoul National University Hospital during the period of February 1979 through September 1982. The minimum follow-up period was 24 months. The review of histologic slides was available in 36 cases. Waldeyer's ring was the most common extranodal sites $(40\%)$. $41\%$ of patients were in the stage 1 and $59\%$ in the stage II by Ann Arbor classification. Of the 44 patients who responded after radiotherapy, 24 patients$(54.4\%)$subsequently relapsed. Regional recurrence rate was $29\%$, distant metastasis was $54\%$ and simultaneous regional recurrence and distant metastasis was $17\%$. The survival rate and disease free survival at 2 years were $57\%\;and\;45\%$ respectively. Those patients with a large primary lesion (over 6cm in diameter), multiple conglomerated, extranodal site and diffuse ceil type, experienced a high rate of distant metastasis. Therefore it seems desirable to study the use of adjuvant chemotherapy in those patients with a high probability of distant metastasis.

• Korean Journal of Head & Neck Oncology
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• v.13 no.2
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• pp.187-199
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• 1997

Thyroid carcinoma ranks low in incidence and as a cause of death when compared to carcinomas arising in the other site. With adequate surgical treatment, the prognosis of operable thyroid carcinoma is good. However, the extent of surgical resection in treatment of thyroid cancer remains still controversy. The aim of this study was to assess the results of thyroid cancer patients treated surgically and to analyze the prognostic factors affecting survival and to improve the survival rate. We retrospectively analyzed the outcome of a total of 278 thyroid cancer patients treated surgically at Inje University Paik Hospital from 1980 to 1995 and followed for 1 to 16 years. There were man in 47 and woman in 231 patients with age range of 14 to 79 years(mean 42 years). Histopathologic findings were papillary carcinoma in 233, follicular carcinoma in 33, mixed carcinoma in 7, medullary carcinoma in 2, and undifferentiated carcinoma in 3 patients, respectively. Operative procedures were unilateral lobectomy in 111, subtotal thyroidectomy in 100, and total thyroidectomy in 67 patients. Central node dissection was performed in 92, modified neck disseciton in 62, radical neck dissection in 28, and no node dissection in 96 patients. Thyroid hormone was administered for the period of 3 to 5 years to suppress endogenous TSH production. Overall 5-year survival rate according to Kaplan-Meier method was 91.1%. Independently, significant factors affecting the prognosis were age at diagnosis, tumor size, pathologic type, tumor stage, lymph node metastasis, angioinvasion, extrathyroidal extension, and 'risk' group category. but, the prognosis were not influenced by sex and capsular invasion. Patients at low risk or with small size carcinomas had long survival over 5 years with only lobectomy. Lymph node dissection was carried out with a limited type in no jugular metastasis, radical neck dissection was performed only therapeutically in proved jugular node metastasis. Fifteen patients were dead of tumor recurrence after surviving for three months to two and half years, and the cause of death was local recurrence in nine, bone metastasis in four and lung metastasis in two patients. In conclusion, more extensive surgery including total thyroidecotmy and systematic compartment-oriented dissection of the lymph node metastases in patient at high-risk group will results in better survival and lower recurrence rate.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.5
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• pp.542-549
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• 1999

The hydrothermal extracts were produced from fish head and their functional properties were investigated. The extracts exhibited an antioxidative effect and synergistic effect with $\alpha$-tocopherol by measuring peroxide values. The $5\%$ solution showed more antioxidative effect than $1\%$ solution. The extracts showed cryopropective effect, but the effect was less than sucrose. The solubility of the extracts was over $70\%$ in the all range of pH, and its lowest solubility was shown in pH 3.0. The extracts exhibited an emulsifying activity less than sugar ester (EAI=34.72) and little higher than or similiar to egg white (EAI= 14.69). The extracts showed a relatively high foam activity. The osmolality of the hydrothermal extracts at $1.0\%$ concentration were 23$\~$31 mOsmole which were much lower than 317 mOsmole at $1\%$ NaCl.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.16 no.5
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• pp.91-107
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• 2021

As competition in the domestic franchise industry is more heated than ever, we examined the factors that affect the profitability of the coffee franchise industry, which has grown rapidly over the last decade, and explored what effect preparatory startup education has on the profitability of coffee franchise stores. Specifically, this study looked into whether preparatory startup education can increase store competitiveness, provide insight into store location selection, generate innovative management, and ultimately contribute to store profitability. To test these hypotheses, we employed structural equation modeling. Results showed that preparatory startup education has a significantly positive (+)effect on 1)business characteristics: taste, quality, price affordability, menu diversity, store ambiance, 2)location characteristics: suitability, and 3)innovation management: accessibility, delivery service, and SNS marketing. The factors with a significantly positive (+)effect on store profitability were taste, quality, and price affordability with regard to business characteristics, suitability in terms of location characteristics, and SNS marketing in respect to innovation management. We expect that this study will have practical implications for increasing the profitability of coffee franchise stores, which are facing excessive competition, and its findings will be useful for coffee franchise head offices as well as government when making relevant policy decisions. In addition, it is intended to deliver a message to franchise head offices, central government, and local governments that they should provide institutional support to coffee franchise stores such that delivery services can lead to substantial improvement in profitability, even when delivery costs are considered.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.3
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• pp.213-220
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• 2015

Wireless sensor network(WSN) is made up of a lot of battery operated inexpensive sensors that, once deployed, can not be replaced. Therefore, energy efficiency of WSN is essential. Among the methods for energy efficiency of the network, clustering algorithms, which divide a WSN into multiple smaller clusters and separate all sensors into cluster heads and their associated member nodes, are very energy efficient routing technique. The first cluster-based routing protocol, LEACH, randomly elects the cluster heads in accordance with the probability. However, if the distribution of selected cluster heads is not good, uniform energy consumption of cluster heads is not guaranteed and it is possible to decrease the number of active nodes. Here we propose a new routing scheme that, by comparing the remaining energy of all nodes in a cluster, selects the maximum remaining energy node as a cluster head. Because of decrease in energy gap of nodes, the node that was a cluster head operates as a member node much over. As a result, the network lifespan is increased and more data arrives at base station.

• Clinics in Shoulder and Elbow
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• v.10 no.1
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• pp.50-58
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• 2007

Purpose: To report our experience with nine cases of pathologic synovial plica on radiohumeral joint which symptom of painful snapping elbow was improved by arthroscopic resection. Materials and Methods: Between 1999 and 2004, 43 cases of elbow arthroscopy were performed by one surgeon. Eight patients with nine cases showed pathologic synovial plica in conjunction with snapping or posterolateral elbow pain. The mean age of eight patients (man: 7, woman: 1) was 29 years (range $16{\sim}56$ years). All patients had a trial of conservative treatment at least six months (range $6{\sim}16$ months). The diagnosis was confirmed before surgery in six cases and at the time of surgery in three cases. Pain, snapping, and subjective results were evaluated at least 12 months in the average(range $12{\sim}24$). Results: All patients showed a hypertropic lateral synovial plica with local synovitis. Seven of them had an associated lesion of chondromalacia on radial head. One of them was associated with radiocapitellar arthritis and had a wrapping over the radial head. Six patients experienced improved posterolateral pain at the end of study (VAS<1). However, the other two patients had occasional pain with activity. One of them persisted with mechanical symptoms, which was treated with additional arthroscopic procedure. Conclusion: Synovial plica in elbow should be considered as an important entity of common elbow disease, especially when pain in the lateral aspect of the elbow with a snapping sensation during motion is featured in patients. The arthroscopic resection seems to be safe and efficient in the short and long term treatment of plica in the elbow joint.

• Korean Journal of Head & Neck Oncology
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• v.24 no.1
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• pp.26-32
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• 2008

Purpose：Hypopharyngeal carcinoma is usually diagnosed as an advanced disease after an asymptomatic beginning, and it is related to a high frequency of lymph node metastases. An eventual negative outcome may occur not only because of possible locoregional failures but also for frequent distant metastases. Thus, the efficacy of induction chemotherapy followed by radiation therapy, with regards to the response, survival rate and complications for locally advanced hypopharyngeal carcinoma patients, was examined. Methods and Materials：Since July 1998 to February 2001, 18 patients having locally advanced hypopharyngeal carcinoma were treated with induction chemotherapy followed by radiation therapy, and the results were retrospectively analyzed. The regimen of the induction chemotherapy was the 5-flurouracil(5-FU, 1,000mg/$m^2$ daily for 5 consecutive days) and cisplatin(100mg/$m^2$ on day 1) combination at 3-week intervals for 2 cycles. The total radiation dose for the primary tumor and metastatic lymph nodes was 68.4-72.0Gy(median：70.2Gy) Results：The 3-year overall survival rate and disease free survival rate were 31.3% and 22.2%, respectively. In 6 patients(33.3%), preservation of the larynx for over 3 years was possible. After the induction chemotherapy and radiotherapy, a complete response was noted in 14 patients(77.8%), and a partial response in 4 patients (22.2%), with an overall response rate of 100%. Conclusion：Induction chemotherapy followed by radiation therapy is an effective treatment and larynx preservation rate was 33% in patients with locally advanced hypopharyngeal carcinoma in our report.