• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.41 no.4
• /
• pp.9-21
• /
• 2004

In this paper, we proposed the image hiding method which decreases calculation amount by encrypt partial data using discrete wavelet transform and linear scale quantization which were adopted as the main technique for frequency transform in JPEG2000 standard. Also we used the chaotic system which has smaller calculation amount than other encryption algorithms and then dramatically decreased calculation amount. This method operates encryption process between quantization and entropy coding for preserving compression ratio of images and uses the subband selection method and the random changing method using the chaotic system. For ciphering the quantization index we use a novel image encryption algerian of cyclically shifted in the right or left direction and encrypts two quantization assignment method (Top-down/Reflection code), made change of data less. Also, suggested encryption method to JPEG2000 progressive transmission. The experiments have been performed with the proposed methods implemented in software for about 500 images. consequently, we are sure that the proposed are efficient image encryption methods to acquire the high encryption effect with small amount of encryption. It has been shown that there exits a relation of trade-off between the execution time and the effect of the encryption. It means that the proposed methods can be selectively used according to the application areas. Also, because the proposed methods are performed in the application layer, they are expected to be a good solution for the end-to-end security problem, which is appearing as one of the important problems in the networks with both wired and wireless sections.

• The Korean Journal of Nuclear Medicine
• /
• v.32 no.1
• /
• pp.10-19
• /
• 1998

The SPECT radiopharmaceuticals labeled with I-123 for dopamine transporter imaging have been used to measure dopamine transporters in patients with movement disorders. However, a cyclotron produced I-123 limits its availiability and ease of use as a radioisotope to be labeled with pharmaceuticals in routine clinical diagnostic procedures. Recently, new radiophannaceuticals for Tc-99m which has optimal characteristic for SPECT imaging have been developed to overcome the limits of using I-123. The purpose of this study was to compare the quality of [Tc-99m]TRODAT-1 with [I-123]IPT SPECT data and then to evaluate the usefulness of [Tc-99m]TRODAT-1 SPECT by using three noninvasive simplified quantitative methods. TRODAT-1 labeled with Tc-99m($15.93{\pm}0.82mCi$) and IPT labeled with I-123($6.60{\pm}0.11mCi$) were injected into five normal controls. Dynamic [Tc-99m]TRODAT-1 SPECT scans of brain were performed for 10 minutes each over 180 minnutes, and for 20 minutes at 4 hrs and 5 hrs. [I-123]IPT SPECT scans were performed for 5 minutes each over 120 minutes. Time activity curves were generated for the left basal ganglia(LBG), right basal ganglia(RBG), and occipital cortex(OCC). Dopamine transporter parameters were ohtained using (BG-OCC)/OCC, graphical method($R_V$), and area ratio method($R_A$). TRODAT-1 and IPT SPECT imaging showed high uptake at the level of the basal ganglia. (BG-OCC)/OCC ratios for TRODAT-1 and IPT were $0.80{\pm}0.14$, and $3.22{\pm}0.81$, $R_Vs$ were $0.62{\pm}0.12$, and $2.30{\pm}0.35$, and $R_As$ were $0.37{\pm}0.08$ and $1.73{\pm}0.31$, respectively. In conclusion, further improvement of [Tc-99m]TRODAT-1 imaging characteristics may be required to estimate the dopamine transporter concentrations in human brains although it shows clear BG localization.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.45 no.3
• /
• pp.370-377
• /
• 2018

Although the frequency of composite resin restoration in children is gradually increasing, there are insufficient researches about the rate of composite resin repair in children. The purpose of this study was to evaluate the repair rate of composite resin restorations in the permanent first molar in children under 12 years old. This study retrospectively analyzed 169 children treated with composite resin restoration in the permanent first molar from May 2014 to April 2015. According to the location of the tooth, the repair rate was higher in the mandible than maxilla and in the left than right. In the classification of restoration, the repair rate was the highest in the class II cavity, and the repair rate was the lowest in the restoration of the occlusal surface only. Repair rate in two years was 14.8%, and repair hazard ratio decreased with age. The most common reason of composite resin restoration replacement was the secondary caries (74.1%). Within the limits of study, the repair rate of children was higher than that of adult due to the characteristics of children. Therefore, dentists should understand these characteristics and try to reduce the repair rate of composite resin composite restorations.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.2
• /
• pp.212-220
• /
• 2020

This study examines the effects on isometric lumbar extension strength, dynamic balance ability, and range of motion, after administering 8 weeks SEBT exercise (dynamic balance exercise) and Lumbar Stabilizing exercise, to open laser lumbar microdiscectomy patients. Totally, 14 patients who underwent preservation treatment for 6 weeks after undergoing open laser lumbar microdiscectomy, were enrolled for the study. Patients were randomly assigned to the Lumbar Stabilizing Exercise Group (LSG, n=7) and SEBT Exercise + Lumbar Stabilizing Exercise Group (SGLS, n=7). Results indicate that isometric lumbar extension strength ratio significantly decreases after 8 weeks rehabilitation exercise in both the LSG (p=0.007) as well as SLSG (p=0.024) groups. Normalized reach distance of the three directions in the Y-balance test to examine the dynamic balance capability showed a significant increase in both groups. The dynamic balance capability showed significant increase to the left (LSG, p=0.010; SLSG, p=0.002) and right (LSG, p=0.002; SLSG, p=0.002). Moreover, significant increase was also obtained in the range of joint operation, in both LSG (p=0.006) and SLSG (p=0.017) groups. These results indicate that both groups of rehabilitation exercise achieve positive outcomes on the isometric lumbar extension strength, range of motion, and dynamic balance ability. However, some results suggest that the SEBT program is likely to have a better efficacy.

• Korean Journal of Head & Neck Oncology
• /
• v.13 no.2
• /
• pp.213-220
• /
• 1997

Background: Thyroid cancer is a relatively rare neoplasm and its incidence varies geographically and ethnically around the world. Thyroid cancer is the most common endocrine malignancy, but it has a wide spectrum of biologic behavior, histologic appearance, and management. Purpose: The purpose of the study was to analyse and evaluate all aspects of the clinical consideration in thyroid cancer. Method: Between 1986 and 1995, a retrospective analysis of 77 thyrod cancer patients admitted at the Department of Surgery, Hangang Sacred Heart Hospital, Hallym University was made to assess clinical entities. Result: By the pathological classification, the papillary carcinoma was the most common type(83.1%). Male to female ratio was 1 : 5.4 and most prevalent age group was noted from fourth decade to fifth decade(46.8%). The most common duration of illness between the appearance of the symptoms and the treatment was below 6 months(44.2%), and the most common symptom was the palpable mass at the anterior portion of the neck(96.1%). Most cases of the thyroid cancer were appeared as cold nodule in the $^{99m}$Tc-thyroid scan(95.7%). In the site of tumor location, the right and left lobe was distributed similarly. In the extent of tumor, incidence of intrathyroidal location was 41.6%, and that of the metastasis to the cervical lymph nodes was 44.2% and that of the direct capsular invasion was 27.3%, and incidence of both involved case was 13%. Surgical procedures were total thyroidectomy alone in 27 cases(35.1%) or with modified neck dissection in 6 cases(7.8%), or with radical neck dissection in 2 cases (2.6%), near total thyroidectomy alone in 22 cases(28.6%), ipsilateral lobectomy with isthmectomy alone in 12 cases(15.6%) or with modified neck dissection in 1 case(1.3%), and biopsy only in 7 cases(9.1%). The most common postoperative complications were transient hypoparathyroidism(5.2%) and transient unilateral recurrent laryngeal nerve paralysis(5.2%). Conclusion: The major problem of management of thyroid cancer include a wide spectrum of clinical behaviour of this tumor entity, the lack of reliable prognostic factors and lack of an objective assessment of the various treatment modalities. But because of showing the favorable prognosis for most thyroid cancer, appropriate and aggressive management should be recommended.

• Korean journal of food and cookery science
• /
• v.17 no.4
• /
• pp.353-358
• /
• 2001

The leaves of Duchung(Eucommia ulmoides), an oriental medicinal plant, have a peculiar aroma of Chinese medicine and astringent taste, which make the consumer be reluctant to Duchung leaf tea. Therefore, the purpose of this study was to develop a mild flavored Duchung leaf tea by mixing with other plants. The flavor patterns of developed tea were analyzed using an electronic nose. Polygonatum odoratum and Elsholtzia splendens were used for improving the flavor of Duchung leaf tea. The addition of 20, 30 and 40% of Polygonatum odoratum improved the overall acceptance in hedonic sensory evaluation. The flavor pattern of the tea was described by principal component analysis(PCA) and the resistance ratio(R/cub gas/R$\_$air/) of sensors. The PCA plot was also used to explain the mild flavor of the tea, which was extended from the right side(positive value of the first principal component) to the left side(negative value). Analysis by using an electronic nose with metal oxide sensors could be applied to detect whether mixed Duchung leaf tea was acceptable or not.

• Journal of Chest Surgery
• /
• v.29 no.6
• /
• pp.614-620
• /
• 1996

The method of treatment in lung cancer patients with invasion to parietal pleura, diaphragm, peri- cardium or vertebra is controversial, and resection of these invasion together with pneumonectomy is called "complex pneumonectomy" From March 1990 to February 1994 we performed 18 cases of "complex pneumonectomy". Seven patients had resection of chest wall, 10 patients had pericardial re- section, and one patient had resection of diaphragm Right pneumonectomy was done in 8 cases and left pneumonectomy was done in 10 cases. The age of patients were from 40 to 70 years(mean 58 years) with male to female ratio of 17 to 1. The chief complaints of the patients on admission were cough (13), dyspnea on exertion (11), chest pain (10), weight loss (9), general fatigue (9), and sputum production (4 . Postoperative pathology were 13 squamous cell carcinoma, 3 adenocarcinoma, and one case each of adenosquamous carcinoma and small cell carcinoma. The postoperative pathologic stages were 2 T3NO MO, 4 TIWIMO, 6 T3N2MO, 5 T4N2MO, and 1 TIWIMO. There was one operative mortality(5.5%). Excluding one follow up loss, 14 patients expired during the follow-up and the mean survival was 9.07 $\pm$ 4.82 months. One patient with stage TINOMO who had chest wall resection is alive at 35 months follow-up and a patient with T3N2MO who had diaphragm resection is alive at 36 months follow-up. Therefore, selection of patients for "complex pneumonec- tomy" is very important, and a long term survival is possible.ong term survival is possible.

• Advances in pediatric surgery
• /
• v.13 no.2
• /
• pp.194-202
• /
• 2007

It is known that pediatric inguinal hernia is caused by the incomplete closure of processus vaginalis (PV). In the case of unilateral hernia, possibile contralateral patent PV should be considered because of its delayed appearance as well as its risk of incarceration. Direct visualization of patent PV could be done by contralateral exploration or by indirect exploration through the ipsilateral opening site of the affected hernia assisted with laparoscope. A patient group (321 persons) to whom laparoscopy was not performed from March 2000 to March 2003 was analyzed and compared with a patient group (280 persons) to whom laparoscopy was performed from April 2003 to September 2005. With all 601 patients, the sex ratio (male/female) of patients was 3.8:1. The side distribution was 57.7% in the right, 32.1% in the left and 10.1% in bilateral. There was no difference of sex and side distribution between before and after laparosopy adoption. We did not find an age correlation in natural closure of the residual PV of the peritoneum. Contralateral hernia developed in 14 persons (2.5%) after the operation of unilateral inguinal hernia before laparoscope adoption. But no contralateral hernia developed after April 2003 with laparoscopy. We think that if we use laparoscopy, being a safe and accurate method, to check whether the contralateral residual PV is opened or closed, possible future contralateral operation can be avoided.

• Journal of the Korean GEO-environmental Society
• /
• v.24 no.2
• /
• pp.5-12
• /
• 2023

In this study, the amount of heaving soil and the heave characteristics of the heaving soil generated at the actual site were quantitatively analyzed through DCM laboratory test construction. By reproducing a series of construction processes of the DCM method in a large-scale soil tank close to the actual site, the amount of heaving soil was predicted and the elevation characteristics such as elevation, diffusion range, diffusion angle and amount of elevation of the heaving soil were evaluated. As a result of the laboratory test construction, the actual elevation in terms of similarity within the DCM improvement section is 0~8.18m, and an average of 3.50m is observed. The actual diffusion range of the heaving soil converted to the similarity ratio is distributed from 28.0 to 38.0m on the left and right sides of the improvement section. The total amount of heaving soil calculated by the SUFFER program based on the results of the laboratory test construction is 19,901m³. Compared with the injected slurry amount of 16,992m³, the amount of heave compared to the injected amount is analyzed as 85.4%. The diffusion angle of DCM heaving soil, which analyzed the results of DCM laboratory test construction with the SUFFER program, is measured to be 30.0~38.0° at a depth of 50.0m, and is evaluated as an average of 34.0°. On the other hand, based on the DCM laboratory test construction and the analysis results using the program performed in this study, the amount of heaving soil at the DCM depths of 40.0m and 60.0m is predicted.

• Journal of radiological science and technology
• /
• v.31 no.2
• /
• pp.141-147
• /
• 2008

Thyroid nodules are a common disease in clinical practice. Fine needle aspiration (FNA) is an accurate and safe method for the diagnosis of thyroid nodules. One of the limitations of FNA is the variable rate of unsatisfactory specimens, especially in small sized, deep seated or complex cystic nodules. To overcome this problem, ultrasound-guided FNA (US-FNA) has been widely used. In this study, the clinical usefulness of US-FNA cytology in thyroid nodules was investigated. Female to male ratio was 6.58:1. The incidence of nodules were 157 (43.1%) cases on the right, 130 (35.7%) cases on the left and 9 (2.5%) cases in isthmus. Total 139 cases (38.2%) belong to less than 1cm and 225 cases (61.8%) belong to more than 1cm. As for the echo type in the nodules, solid types were 255(70.1%), cystic type 39 (10.7%) cases, and the percentage of mixed type was 19.2%. The results show that US-FNA reduces the possibility of unsatisfactory cytologic specimens and the rate of false-negative diagnosis, and improves the diagnostic accuracy in investigation thyroid nodules.