• Investigative Magnetic Resonance Imaging
• /
• 제21권4호
• /
• pp.233-241
• /
• 2017

Purpose: To report on the current practices in breast magnetic resonance imaging (MRI) in Korea. Materials and Methods: We invited the 68 members of the Korean Society of Breast Imaging who were working in hospitals with available breast MRI to participate in a survey on how they performed and interpreted breast MRI. We asked one member from each hospital to respond to the survey. A total of 22 surveys from 22 hospitals were analyzed. Results: Out of 22 hospitals, 13 (59.1%) performed at least 300 breast MRI examinations per year, and 5 out of 22 (22.7%) performed > 1200 per year. Out of 31 machines, 14 (45.2%) machines were 1.5-T scanners and 17 (54.8%) were 3.0-T scanners. All hospitals did contrast-enhanced breast MRI. Full-time breast radiologists supervised the performance and interpreted breast MRI in 19 of 22 (86.4%) of hospitals. All hospitals used BI-RADS for MRI interpretation. For computer-aided detection (CAD), 13 (59.1%) hospitals sometimes or always use it and 9 (40.9%) hospitals did not use CAD. Two (9.1%) and twelve (54.5%) hospitals never and rarely interpreted breast MRI without correlating the mammography or ultrasound, respectively. The majority of respondents rarely (13/21, 61.9%) or never (5/21, 23.8%) interpreted breast MRI performed at an outside facility. Of the hospitals performing contrast-enhanced examinations, 15 of 22 (68.2%) did not perform MRI-guided interventional procedures. Conclusion: Breast MRI is extensively performed in Korea. The indication and practical patterns are diverse. The information from this survey would provide the basis for the development of Korean breast MRI practice guidelines.

• 융합신호처리학회논문지
• /
• 제12권4호
• /
• pp.274-280
• /
• 2011

최근 연구가 활발히 전행되고 있는 IP기반 무선 센서네트워크 기술은 현대인들 삶의 질적 향상이나 요구사항을 만족시키기 위해 반드시 필요한 기술 중의 하나이다. IP기반 무선 센서네트워크의 대표 기술로는 6LoWPAN 프로토콜이 있다. 기존 6LoWPAN 프로토콜 상에서 제공되는 기능 중 단편화 기법은 여러 개의 IEEE 802.15.4 프레임이 나뉘어져 도착하는 것을 말하는데, 센서네트워크의 프로토콜 데이터 단위가 102바이트인데 반해 IPv6의 최대 전송 단위가 1280바이트로 큰 차이를 보이기 때문에 이를 극복하기 위한 기술로 단편 패킷 전송의 특성상 많은 에너지 소모가 일어난다. 본 논문에서 제안한 ID 기반 단편 패킷 전송 기법을 적용한 결과 주소 방식(16, 64bit)에 따라 약 7-22% 정도 전송횟수가 감소되었다. 뿐만 아니라, 기존 LOAD 라우팅 프로토콜을 사용하여 경로 설정을 할 경우 센서노드가 통신을 할 수 없는 경우가 아니면 한번 설정된 경로는 변하지 않는다. 이는 특정 노드의 에너지 고갈을 야기 시키고 네트워크 전체에 영향을 주기 때문에 적절한 에너지 분배가 이루어져야 한다. 에너지 분배를 고려할 수 있도록 제안한 LOAD 라우팅 프로토콜은 통신이 이루어질수록 전체 네트워크 내에 모든 노드들의 에너지는 균등하게 유지됨을 보였다. 또한 한 번의 라우팅 수행 시 이웃 노드들의 정보를 획득할 수 있어 원 홉 데어터 전송에 소모되는 에너지를 절약할 수 있다. 따라서 본 논문에서 제안된 6LoWPAN 프로토콜은 에너지 제약 조건이 심한 무선 센서네트워크 환경에 매우 적합하다 할 수 있다.

• 대한지역사회영양학회지
• /
• 제10권4호
• /
• pp.525-535
• /
• 2005

This study was conducted to investigate the effect of a 3 week low calorie diet (LCD) and a 9 week of behavior modification (BM) program on the weight loss, mineral and vitamin status in 22 obese women. The subject were healthy, obese (PIBW> $120\%$) women aged 20 - 50 Yr and not taking any medications known to influence body composition, mineral or vitamin metabolism During the LCD program, subjects were provided commercial liquid formulas with 125 kcal per pack and were instructed to have a formula for replacement of one meal and at least one regular meal per day within the range of daily 800 - 1200 kcal intake. During the BM program the subjects weekly attended the group nutrition counseling session to encourage themselves to modify their eating behavior and spontaneously restrict their energy intakes. The BM program focused on stimulus control, control of portion sizes and modification of binge eating and other adverse habits. The initial mean energy intake of subjects was 2016.9 $\pm$ 129.8 kcal ($100.8\%$ of RDA) and dropped to 1276.5 $\pm$ 435.7 kcal at the end of a 3 week of LCD program and elevated to 1762 $\pm$ 329.3 kcal at the end of a 9 week of BM program. Carbohydrate, protein and fat intakes were significantly decreased at the end of the LCD but carbohydrate was the only macro nutrient that showed significant decrease (p < 0.05) at the end of the BM program compared to baseline. Calcium and iron intakes decreased significantly (p < 0.01, respectively) with no significant changes in other micronutrients at the end of the LCD. The mean weight of the subjects decreased from 73.8 $\pm$ 8.0 kg to 69.2 $\pm$ 7.7 kg with LCD and ended up with 67.7 $\pm$ 7.1 kg after 9 weeks of BM. The 3 weeks of LCD reduced most of the anthropometric indices such as BMI, PIBW, fat weight, wast-to-hip ratio and subscapular and suprailiac skinfold thickness. The 9 weeks of behavior modification showed slight change or maintenance of each anthropometric measurements. Weight loss and decreased WHR with the diet program induced significantly decreased systolic blood pressure. SGOT, SGPT and serum insulin levels with improved serum lipid profiles. Biochemical parameters related to iron status such as hemoglobin, hematocrit were significantly decreased (p < 0.01) at the end of the LCD. But their mean values were within normal range. The mean serum 25 (OH) vitamin $D_3$ level significantly increased after whole diet program. Serum folate level significantly decreased after 12 weeks of diet program. In conclusion 3 weeks of LCD brought 4.6 kg reduction in body weight without risk of iron, zinc or vitamin D deficiency and 9 weeks of the BM was effective to maintain nutritional status with slightly more weight reduction (1.5 kg). However calcium intake and serum folate should be monitored during the LCD and BM because of increased risk of deficiencies.

• 한국균학회지
• /
• 제31권1호
• /
• pp.22-27
• /
• 2003

본 연구에서는 병 재배 버섯 안정생산을 위한 우량종균확보 방법으로서 액체종균을 활용하고자 하였으며 액체종균을 버섯재배에 효율적으로 사용할 수 있는 접종방식 및 접종장치를 개발하였다. 느타리 및 팽나무버섯의 대량 액체배양의 조건은 팽나무버섯은 접종량 $5{\sim}6%$, 배양기간 4일 일 때, 그리고 느타리버섯은 접종량 $5{\sim}6%$, 배양기간 5일에서 최대 균사생장을 확인 할 수가 있었다. 자동접종시스템을 이용하여 균사생장 및 자실체 생산에 대한 조사를 실시한 결과, 느타리버섯의 경우 자실체 생산에서는 접종량 6%, 즉 15ml 에서 수량이 높게 나타났다. 팽나무버섯은 접종량 $4{\sim}6%$, 즉 $10{\sim}15ml$에서 자실체 수량이 다른 조건에 비해 우수하게 나타났다. 액체종균 자동접종시스템을 이용하는 것이 고체종균 접종시스템보다 느타리버섯은 33.7%, 팽나무버섯은 32.8% 증수효과를 확인할 수 가 있었다. 작업성능의 평가를 위해 $4{\times}4$배열의 병 재배용 tray 75개를 이용하여 병의 뚜껑을 제대로 열고 닫지 못하는 경우, 분사가 안되는 경우 등의 오동작은 없었고 작업시간은 26분으로 단축되었다.

• 한국동물위생학회지
• /
• 제40권2호
• /
• pp.107-117
• /
• 2017

This study was conducted to investigate of hepatoprotective effect of dandelion water extract (DWE) according to repeated administration of thioacetamide (TAA) induced hepatotoxicity in Spraque-Dawley rats. Thirty rats were randomly assigned to 5 groups; normal control, DWE-control, TAA-control (TAA injection during the feeding of normal diet), TAA&DWE600 (TAA repeated injection during the feeding of DWE 600 mg/kg BW), TAA&DWE1200 (TAA repeated injection during the feeding of DWE 1,200 mg/kg BW). Rats in DWE-control and TAA&DWE groups were treated with DWE (600 or 1,200 mg/kg BW daily) by gavage for 20 days (twice a day). All the rats in the TAA-control and TAA&DWE groups were repeated injection of TAA (100 mg/kg BW) into the abdominal cavity 3 days interval and 12 hrs later, all rats were sacrificed. At the same time, normal control and DWE-control groups were injected normal saline. In TAA&DWE groups, serum alanine and aspartate aminotransferase (ALT, AST) were significantly decreased and triglyceride (TG) synthesis was significantly increased compared to TAA group. As well as total billilubin and GGT were slightly decreased by the treatment of DWE. Lipid peroxidation (MDA) concentration was significantly decreased and hepatic GSH content was slightly or significantly increased in the TAA&DWE groups compared to TAA group. Hepatic anti-oxidative enzyme activities, such as GSH, GST, SOD and catalase were slightly or significantly elevated by the treatment of DWE. According to these results, When dandelion extract was long term supplied, it could be used as a potential protective material for a longer time liver damage by repeated adminstration of the TAA.

• Nuclear Engineering and Technology
• /
• 제44권5호
• /
• pp.523-534
• /
• 2012

The objective of this study was to experimentally investigate the effect of heat curing methods on the temperature history and strength development of slab concrete exposed to $-10^{\circ}C$. The goal was to determine proper heat curing methods for the protection of nuclear power plant structures against early-age frost damage under adverse (cold) conditions. Two types of methods were studied: heat insulation alone and in combination with a heating cable. For heat curing with heat insulation alone, either sawdust or a double layer bubble sheet (2-BS) was applied. For curing with a combination of heat insulation and a heating cable, an embedded heating cable was used with either a sawdust cover, a 2-BS cover, or a quadruple layer bubble sheet (4-BS) cover. Seven different slab specimens with dimensions of $1200{\times}600{\times}200$ mm and a design strength of 27 MPa were fabricated and cured at $-10^{\circ}C$ for 7 d. The application of sawdust and 2-BS allowed the concrete temperature to fall below $0^{\circ}C$ within 40 h after exposure to $-10^{\circ}C$, and then, the temperature dropped to $-10^{\circ}C$ and remained there for 7 d owing to insufficient thermal resistance. However, the combination of a heating cable plus sawdust or 2-BS maintained the concrete temperature around $5^{\circ}C$ for 7 d. Moreover, the combination of the heating cable and 4-BS maintained the concrete temperature around $10^{\circ}C$ for 7 d. This was due to the continuous heat supply from the heating cable and the prevention of heat loss by the 4-BS. For maturity development, which is an index of early-age frost damage, the application of heat insulation materials alone did not allow the concrete to meet the minimum maturity required to protect against early-age frost damage after 7 d, owing to poor thermal resistance. However, the combination of the heating cable and the heat insulating materials allowed the concrete to attain the minimum maturity level after just 3 d. In the case of strength development, the heat insulation materials alone were insufficient to achieve the minimum 7-d strength required to prevent early-age frost damage. However, the combination of a heating cable and heat insulating materials met both the minimum 7-d strength and the 28-d design strength owing to the heat supply and thermal resistance. Therefore, it is believed that by combining a heating cable and 4-BS, concrete exposed to $-10^{\circ}C$ can be effectively protected from early-age frost damage and can attain the required 28-d compressive strength.

• 한국결정성장학회지
• /
• 제30권5호
• /
• pp.200-207
• /
• 2020

SHS 법으로 MoSi₂ 분말, (Mo_1/2W_1/2)Si₂ 분말 및 WSi₂ 분말을 합성하고 이 분말들을 500℃, 1,000℃, 1,200℃, 1,300℃, 1,400℃, 1,500℃ 및 1,600℃에서 열처리한 다음, 결정구조 및 열중량 변화 등을 관찰하였다. Mo-W-Si계의 silicide 분말은 500℃의 저온에서도 산화 반응이 일어나며, 저온 산화 및 분해로 생성되는 결정상은 MoO₃이었다. 1,200℃ 이상에서 열처리를 한 경우에 분해반응으로 생성된 SiO₂의 결정상은 상온에서 흔히 관찰되는 α-quartz가 아닌 α-cristobalite 상으로 생성되었다. W이 포함되면 저온과 고온에서 분해 반응이 더 많이 일어나는 것으로 나타났으며, 분말을 성형하여 소결한 시편의 경우에 MoSi₂와 (Mo_1/2W_1/2)Si₂는 저온이나 고온에서 1시간 열처리를 하더라도 저온산화에 의한 분해와 그에 따른 질량 변화 반응을 관찰하기 어려웠지만 WSi₂는 저온 산화에 의하여 소결 자체가 어려웠다.

• Advances in pediatric surgery
• /
• 제1권1호
• /
• pp.18-26
• /
• 1995

For the prevention of later contralateral hernia as well as unnecessary contralateral exploration in pediatric patients with unilateral inguinal hernias, a reasonable indication of contralateral exploration is required. To examine the contralateral positivity, a prospective selective contralateral exploration has been performed by the author from Sept. 1985 to Dec. 1993, at Pediatric Surgical Section of the Department of Surgery, Kangnam St. Mary's Hospital, Catholic University Medical College. Among the total 1200 cases of pediatric inguinal hernias, 580 cases of contralateral side were explored at hernia operations, by the indications as; male with infant onset, 2)female of all age, 3)prematurity, 4)profuse ascites due to cirrhosis, nephrotic syndrome, and ventriculoperitoneal shunt, and 5)remarkable silk sign. Overall positive rate was 71.4%, and positive rates of each indication were 80.7%, 70.4%, 73.1%, 66.7%, and 72.0%, respectively. Right side hernia showed 67.0%, left s ide 75.7%, and positive familial history 71.8% of contralateral positivities. In male, getting older revealed lower positive rates and the rate suddenly dropped after 12 years of age. Birth order, mother's age at delivery, postmaturity did not show any significant differences between the rates. Recurrence was seen in 3(0.5%) ipsilateral and 2(0.3%) contralateral, both of which were negative esplorations on previons operations. Overall complication rate was 3.8%, including 1 infection, 14 fluid or blood accumulation, 5 edemas, 3 temporary testicular edemas, 2 persisting fevers, 2 enures is and one delayed recovery from anesthesia. Among 38 cases with contralateral hernias developed after unilateral surgery by authors(6 cases) or surgeons in other institutions, 14 were males with infant onset, 4 were prematurities and 9 were females. Therefore, 27(71.7%) cases were originally under the contralateral exploration indications. The primary site of the hermia was right in 25 and left in 13. With above results, the following indications for contralateral exploration could be suggested ; 1)under one year of age, both sex, 2)prematurity, 3) remarkable silk sign, 4)in the double checked suspicions among males with infant onset, all age females, ascites, left hernia and familial history. After 12 years of age, exploration is not required. Considering complications, contralateral explorations could be considered only in the following situations; 1)expert, experienced pediatric surgeon, 2)experienced pediatric anesthesiologist, 3)operations could be done smoothly in an hour, 4)good general condition of the patient.

• Asia pacific journal of information systems
• /
• 제19권1호
• /
• pp.63-82
• /
• 2009

Virtual community is a social aggregation to attain some goals in an IT-supported virtual space (Lee et al., 2002). As lots of virtual communities generate robust and reliable outputs with low control and low incentive, previous researchers was interested in the questions, "why do they participate?" or "how are they controlled?". But. as Katz (1964) said, the most important part of the high-performing organization is the behaviors of members in the organization. Therefore, this research is to examine the relationship between the performance and the behaviors of participants in the virtual community. First, we propose 6 types of behaviors related to high performance in the virtual community: 'Continuous Attendance', 'Complying with the organizational value, policies, and regulations', 'Protection', 'Suggestion for the improving', 'Self-training', and 'Favorable behavior'. The six types of behaviors are extracted from the framework of Katz (1964) and Brief and Motowidlo (1986). The reason why each behavior is positively related with high-performance is that those who continuously attend have more responsibility than temporary participants do; complying with the rules of a virtual community means that they may make more reliable outcome; 'Protection' is one of the prosocial-behaviors and those who protect the community may concern the benefit of the virtual community when they participate: those who suggest some ideas for improvement may contribute to the virtual community; 'Self-training' behavior means that participants really want to have high quality in their contribution: those who have 'Favorable attitude' consider other members in the virtual community when they participate. Then, we perform an empirical analysis with the survey from participants in the Knowledge service of Naver.com, to show those behaviors are associated with the high-performance. To make the measurement for the six behaviors, we use CVR (content validity ratio) method (Lawshe, 1975), interviewing 12 experts. The dependent variable, performance of participation, is measured by 'ratio of selected answer' given by the Naver.com. We use email survey. We sent 1200 emails to randomly selected participants in the knowledge service and received 282 responses. The results of our empirical analysis show that 4('Continuous Attendance', 'Suggestion for the improving', 'Self-training', 'Favorable attitude') are positively related to the performance, but 2('Complying with the organizational value, policies, and regulations' and 'Protection') are not significant. In line with Fitzgerald (2006), we expect that participants in the virtual community may behave similarly to employees in the off-line firms for the high performance. But 2 behaviors have different results. The reason that the 'Complying with the organizational value' behavior is not sufficiently related to performance is that the motivation of participants is more related to intrinsic pleasure or altruism than external reward. Also, the 'Protection' behavior has no significant relationship with performance, which means that the high-performing participants have little concern about the problems in the community.

• Journal of Korean Neurosurgical Society
• /
• 제30권10호
• /
• pp.1200-1209
• /
• 2001

Objective : A thorough understanding of the related venous structure is mandatory for successful removal of the petroclival meningiomas. This study was planned to investigate the guideline for safe ligation and incision of transverse or sigmoid sinuses and the importance of drainage pattern of vein of $Labb{\acute{e}}$ in surgical removal of petroclival meningiomas. Patients and Methods : The authors reviewed the venogram of the consecutive 37 cases of petroclival meningiomas and retrospectively analyzed their surgical findings. The drainage pattern of confluence of Herophili was classified as Type A(confluent & equal on both sides), Type B(confluent & non-dominant on tumor side), Type C(confluent & dominant on tumor side) and Type D(unilateral drainage only) as these findings gave the information on safe ligation and resection of the sinus. Usefulness of intraoperative test clamping of sinus for safe ligation was also reviewed. The vein of $Labb{\acute{e}}$ was analyzed with respect to its draining point and its collaterals to other superficial veins. Results : Contraindications of the sinus ligation and resection according to the drainage pattern at the confluence of Herophili were Type C(n=10, 27%)and Type D(n=4, 11%). Patients with Type A(n=12, 32%)and Type B(n=11, 30%) were tolerable to sinus ligation ipsilateral to tumor, if the test clamping proved to be safe. Identification of no brain swelling, after intraoperative test clamping of the sinus for more than 30 minutes performed in 7 out of 11 cases, was a reliable indicator of safe sinus ligation. The drainage pattern of the vein of $Labb{\acute{e}}$, especially low-lying type, could predict the possibility of postoperative hemorrhage and infarction. Its drainage into tentorium or superior petrosal sinus, however, made the transtentorial approach impossible, leading to restricted operative field. Conclusion : For a successful removal of the petroclival meningiomas preoperative venogram should be examined carefully. The extent of exposure in a planned approach can be estimated by analyzing the variation of sinuses and the drainage pattern of vein of $Labb{\acute{e}}$.