• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.8
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• pp.2052-2063
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• 1998

Various full-scale radio location systems have been developed since ground-based radio navigation systems appeared during World War II, and more recently global positioning systems (GPS) have been widely used as a representative location system. In addition, radio location systems based on cellular systems are intensively being studied as cellular services become more and more popular. However, these studies have been focused mainly on macrocellular systems of which based stations are mutually synchronized. There has been no study about systems of which based stations are asynchronous. In this paper, we proposed two radio location algorithms in microcellular CDMA systems of which base stations are asychronous. The one is to estimate the position of a personal station at the center of rectangular shaped area which approximates the realistic common area. The other, as a method based on road map, is to first find candidate positions, the centers of roads pseudo-range-distant from the base station which the personal station belongs to and then is to estimate the position by monitoring the pilot signal strengths of neighboring base stations. We compare these two algorithms with three wide-spread algorithms through computer simulations and investigate interference effect on measuring pseudo ranges. The proposed algorithms require no recursive calculations and yield smaller position error than the existing algorithms because of less affection of non-line-of-signt propagation in microcellular environments.

• Korea journal of population studies
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• v.30 no.2
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• pp.71-95
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• 2007

This paper attempts to identify the principle of family succession and family patterns of yangban in the late Chosun period through an analysis of male adaptation cases found in family registration records. The primary source of analysis is the family registration documents of Uiseong Kim's from the late 17th century to the early 20th century. As a result, it is found that there is a substantial change in the patterns of family from the early and mid Chosun period to the late Chosun period. The change is the strengthening of the principle of patriarchy succession through male adoption. Looking at the data as a whole, the average number of household members is increased and the membership of kinship also expanded. In contrast to the family patterns of the early Chosun period, not only the patterns of Uiseong Kim's family are predominately immediate family or collateral family but also the majority is extended family in the 18th and 19th centuries. The male adoption cases recorded in Uiseong Kim's family registration documents take up 33.8% of the male adoption cases in the entire family registration documents. This goes to show that the strengthening of the principle of primogeniture succession at a time when child mortality rate is very high resulted in the increase of male adoption. In conclusion, the late Chosun society was a society where the seat of primogeniture was much more important than immediate hereditary members in the family succession.

• Nuclear Medicine and Molecular Imaging
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• v.41 no.6
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• pp.546-552
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• 2007

Purpose: In the breast cancer patient, lymphatic mapping and sentinel lymph node biopsy are the most important procedure for axillary lymph node staging. We aimed to compare the three radiocolloids [$^{99m}Tc$-antimony trisulfide colloid (ASC), $^{99m}Tc$-tin colloid (TC), and $^{99m}Tc$-human serum albumin (HSA)] for sentinel lymph node mapping. Subjects and Methods: Totally, 397 patients with clinically N0 stage were enrolled. $^{99m}Tc$-ASC was injected in 202 out of 397 patients, $^{99m}Tc$-TC was injected in 120 patients, and $^{99m}Tc$-HSA was injected in the remaining 75 patients. The sentinel lymph nodes were localized by lymphoscintigraphy and selected using intraoperative gamma probe. All sentinel lymph nodes were investigated by intraoperative pathologic consultation. The axillary lymph nodes which were harvested by the lymph node dissection were also investigated. Results: The patients of each group showed similar clinical characteristics. There were no significant differences (p>0.05) in the identification rate of sentinel lymph nodes (IR), false negative rate (FNR), and negative predictive value (NPV). The axillary lymphadenectomy revealed axillary lymph node metastases in those three groups (ASC-33.2%, TC-31.7%, HSA-22.7%). The IR, FNR, and NPV were not significantly different among those groups. Conclusion: Those three $^{99m}Tc$-labeled radiocolloids showed equivalent results in sentinel lymph node mapping of breast cancer.

• Restorative Dentistry and Endodontics
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• v.32 no.4
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• pp.385-396
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• 2007

The aims of this study were to compare the shaping effect and safety between single length technique recommended by manufacturer and crown-down technique using Mtwo rotary file and to present a modified method in use of Mtwo file. Sixty simulated root canal resin blocks were used. The canals were divided into three groups according to instrument and the manner of using methods. Each group had 20 specimens. Group MT was instrumented with single length technique of Mtwo, group MC was instrumented with crown-down technique of Mtwo and group PT was instrumented with crown-down technique of ProTaper. All of the rotary files used in this study were operated by an electric motor. The scanned canal images of before and after preparation were superimposed. These superimposed images were evaluated at apical 1 to 8 mm levels Angle changes were calculated. The preparation time, weight loss, instrument failure and binding, canal aberrations, and centering ratio were measured. Statistical analysis of the three experimental groups was performed with ANOVA and Duncan's multiple range tests for post-hoc comparison and Fisher's exact test was done for the frequency comparison. In total preparation time, group MT and group MC were less than group PT. In the aberrations, group MT had more elbows than those of group MC and group PT. The binding of group MC was least and group MT was less than group PT (P < 0.05). Under the condition of this study, crown-down technique using Mtwo rotary file is better and safer method than single length technique recommended by the manufacturer.

• Journal of Chest Surgery
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• v.34 no.4
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• pp.329-337
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• 2001

배경: 승포판 전엽이나 교련 또는 여러 판엽에 걸쳐 광범위한 병변으로 인한 승모판 역류의 경우 수술수기에 대한 뚜렷한 정립이 되어 있지 않은 실정이다. 최근 이러한 병변의 승모판 역류의 경우 PTEE(Polytetrafluro-ethylene)을 이용한 신건삭 형성술의 시행이 점차 늘고 있다. 이에 저자들은 PTEE를 이용한 신건삭 형성술이 승모판 성형술에 어떠한 영향을 미치는지 알아보고자 하였다. 대상 및 방법: 1994년 1월부터 1999년 12월까지 승모판막 성형술을 시행 받은 322명의 환자 중에서 신건삭 형성술을 이용하여 승모판 성형술을 시행한 144례(I군)과 신건삭 형성술 이외의 방법으로 승모판 성형술을 시행한 178례(II군)를 대상으로 하였다. 두 군에서 수술 직후ㅘ 수술 후 6개월, 1년 및 1년 단위로 주기적인 심초음파를 시행하였고 이를 통계적 검정하였다. 결과: 같은 기간 승모판 성형술은 승모판막 폐쇄 부전증으로 내원한 환자의 95%(306)에서 추적 관찰이 가능하였다. 두 구난에 수술 전 혈류 역학적인 차이를 보이지 않았고, 수술 전 평균 승모판막 폐쇄 부전의 정도는 I군이 3.8$\pm$0.4, II군이 3.6$\pm$0.3였으나 수술 후 추적 관찰에서 각각 1.3$\pm$0.9와 1.1$\pm$0.7 정도의 양호한 판막 성형술의 결과를 보였고 승모판막 면적의변화나 승모판막에서의 평균 압력차이 등 혈류 역학적인 결과에도 차이를 보이고 있지 않았다. 술 후 3명(0.9%)의 조기 사망과 4명 (1.2%)의 후기 사망이 있었으나 두 군간의 차이는 보이지 않았다. 만기 생존율( 93.7$\pm$3.3 vs 88.0$\pm$1.95) 및 판막살패가 발생하기 않을 확률( 93.7$\pm$3.6 vs 93.3$\pm$3.4%) 과 재수술이 필요치 않을 활률(99.3$\pm$0.7 vs 96.0$\pm$1.9%), 색전증, 감염성 심내막염, 판막과 관련된 합병증 발생률 등에서 두 군간에 의미 있는 차이는 없었다. 전엽과 후엽에서 신건삭 형성술을 시행한 환자에서는 통계학적인 차이가 없었다(p=0.29) 결론: 신건삭 형성술을 이용한 승모판 성형술은 승모판 성형술의 증가(r=0.98, p<0.01)를 가져 왔을 뿐만 아니라 내구성과 안정성에 있어 기존의 안전화된 수술 수기와 견줄만하다. 특히 이러한 신건삭 형성술은 승모판 전엽에 병변이 있는 경우와 교련부 및 여러 엽에 광범위한 병변으로 인하여 재건술이 어려운 경우에도 승모판 재건을 가능하게 하는 우수한 수술 수리가 사료된다.

• Journal of Chest Surgery
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• v.32 no.3
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• pp.237-248
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• 1999

Background: The late results of repair of tetralogy of Fallot(TOF) are favorable in most patients. Some portion of the patients with tetralogy, however, require reoperation for residual lesions or result in late death. The outcome of patients after tetralogy repair performed during the past 13 years was studied, with an emphasis on postrepair survival and problems including reoperations. Material and Method: A retrospective review of clinical, echocardiographic and catheterization data was performed in 569 of 775 patients with TOF who underwent corrective repair between 1983 and 1995 at Sejong General Hospital, Buchon, Korea. Result: Of 28(4.9%) early deaths(defined as 30 days postrepair), 12 deaths(42.9%) were <1 year of age, with an operative mortality of 15.4%. The surviving 541 patients(age 2.8 months to 43.4 years, median 23 months) have been followed up from 1 month to 12.6 years(median 35 months) postoperatively. Most patients were in good functional class and had normal right ventricular(RV) function. Postrepair results were compared between the transatrial-transpulmonary approach and the conventional right ventriculotomy. The former technique provided a lesser incidence of significant pulmonary regurgitation(P<0.001) and alesser degree of RV dysfunction(P<0.05) compared with those in the latter. There were 10(1.8%) late deaths during the follow-up period and 6 of the deaths were directly related to reoperation or ventricular dysfunction. The 10-year actuarial survival rate was 96.7%. There were 44 reoperations(8.1%) in 39 patients(7.2%), with an operative mortality of 10.3%. The main indications or reoperation included residual ventricular septal defect(VSD) (n=6), pulmonary stenosis(PS) (n=11), VSD with PS(n=17), pulmonary regurgitation(n=7), and tricuspid regurgitation(n=2). The 5- and 10-year freedom from reoperation were 89.4% and 76.1%, respectively. Conclusion: Although the majority of patients with repaired TOF are clinically well, with a high rate of survival, approximately 7% of patients have residual lesions that require surgical therapy. Therefore, the timely and meticulous corrective repair is mandatory to avoid reoperation, and continued close surveillance is also needed for the early detection of residual problems.

• Journal of Technology Innovation
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• v.17 no.2
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• pp.1-23
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• 2009

The Survey on the Industrial Research and Development(R&D) is the primary source of information on R&D performed by Korea industrial sector. The results of the survey are used to assess trends in R&D expenditures. Government agencies, corporations, and research organizations use the data to investigate productivity determinants, formulate tax policy, and compare individual company performance with industry averages. Recently, Korea Industrial Technology Association(KOITA) has collected the data by complete enumeration. Koita has, currently, considered sample survey because the number of R&D institutions in industry has been dramatically increased. This study develops survey design for the industrial research and development(R&D) statistics by introducing a sample survey. Companies are divided into 8 groups according to the amount of R&D expenditures and firm size or type. We collect the sample from 24 or 8 sampling strata and compare the results with those of complete enumeration survey. The estimates from 24 sampling strata are not significantly different to the results of complete enumeration survey. We propose the survey design as follows: Companies are divided into 11 groups including the companies of which R&D expenditures are unknown. All large companies are included in the survey and medium and small companies are sampled from 70% and 3%. Simple random sampling (SRS) is applied to the small company partition since they show uniform distribution in R&D expenditures. The independent probability proportionate to size (PPS) sampling procedure may be applied to those companies identified as 'not R&D performers'. When respondents do not provide the requested information, estimates for the missing data are made using imputation algorithms. In the future study, new key variables should be developed in survey questionnaires.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.64 no.2
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• pp.127-136
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• 2019

Sweet sorghum (Sorghum bicolor L. Moench), compared to traditional crops, has been evaluated as a useful crop with high adaptability to the environment and various uses, but cultivation has not expanded owing to a lack of related research and information in Korea. This study was conducted to estimate heading date in 'Chorong' sweet sorghum based on climate data of the last 30 years (1989 - 2018) from six regions (Jeonju, Buan, Jeongup, Imsil, Namwon, and Jangsu) in Jellabuk Province. In addition, we compared the growth and quality factors by sowing date (April 10, April 25, May 10, May 25, June 10, June 25, and July 10) in 2018. Days from sowing to heading (DSH) increased to 107, 96, 83, 70, 59, 64, and 65 days in order of the sowing dates, respectively, and the average was 77.7 days. The effective accumulated temperature for heading date was $1,120.3^{\circ}C$. The mean annual temperature was the highest in Jeonju, followed in descending order by Jeongup, Buan, Namwon, Imsil, and Jangsu. The DSH based on effective accumulated temperature gradually decreased in all sowing date treatments in the six regions during the last 30 years. DSH of the six regions showed a negative relationship with mean temperature (sowing date to heading date) and predicted DSH ($R^2=0.9987**$) calculated by mean temperature was explained with a probability of 89% of observed DSH in 2017 and 2018. At harvest, fresh stem weight and soluble solids content were higher in the April and July sowings, but sugar content was higher in the May 10 ($3.4Mg{\cdot}ha^{-1}$) and May 25 ($3.1Mg{\cdot}ha^{-1}$) sowings. Overall, the April and July sowings were of low quality and yield, and there is a risk of frost damage; thus, we found May sowings to be the most effective. Additionally, sowing dates must be considered in terms of proper harvest stage, harvesting target (juice or grain), cultivation altitude, and microclimate.

• 한국노년학
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• v.36 no.4
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• pp.1003-1024
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• 2016

The human rights of older people have gotten more attention recently in South Korea, a country that is in transition to a super-aged society. This study aimed to systematically review studies on elder abuse and related factors among community-dwelling older adults in South Korea over twenty years (1994-2016). We searched major databases (Riss, DBpia, KISS, KMbase, and PubMed) and identified published studies relevant to the topic. Based on inclusion and exclusion criteria related to study quality, a total of 31 studies were selected for this review. We examined types, measurements, and risk factors of elder abuse as well as study designs in the selected studies, guided by Johannesen's theoretical framework on elder abuse. All of the reviewed studies on elder abuse in Korea were cross-sectional studies, most of which focused on older people living in urban areas, using a non-random sampling method. All of the studies focused on certain types of elder abuse only. Some adopted elder-abuse instruments that were not validated, and others used self-developed instruments without psychometric tests. As for the risk factors of elder abuse in South Korea, the physical and mental health of the victims and aggressors impacted the risk of elder abuse, but general sociodemographic factors such as age, sex, and education were less likely to be related to the risk. In addition, decreasing caregiver burden and building elder-friendly communities are important for the prevention of elder abuse. Needed are further empirical studies on elder abuse with a theoretical framework that gives consideration to the unique sociocultural contexts of Korea. It is also recommended to develop instruments to measure elder abuse reflecting the sociocultural contexts of Korea, and to examine the multi-dimensional risk factors of elder abuse.

• The Korean Journal of Nuclear Medicine Technology
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• v.25 no.1
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• pp.21-28
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• 2021

Purpose Brown fat, or brown adipose tissue (BAT), is involved in non-shivering thermogenesis and creates heat through glucose metabolism. BAT activation occurs stochastically by internal factors such as age, sex, and body mass index (BMI) and external factors such as temperature and environment. In this study, as a retrospective, electronic medical record (EMR) observation study, statistical analysis is conducted to confirm BAT activation and various factors. Materials and Methods From January 2018 to December 2019, EMR of patients who underwent PET/CT scan at the National Cancer Center for two years were collected, a total of 9155 patients were extracted, and 13442 case data including duplicate scan were targeted. After performing a univariable logistic regression analysis to determine whether BAT activation is affected by the environment (outdoor temperature) and the patient's condition (BMI, cancer type, sex, and age), A multivariable regression model that affects BAT activation was finally analyzed by selecting univariable factors with P<0.1. Results BAT activation occurred in 93 cases (0.7%). According to the results of univariable logistic regression analysis, the likelihood of BAT activation was increased in patients under 50 years old (P<0.001), in females (P<0.001), in lower outdoor temperature below 14.5℃ (P<0.001), in lower BMI (P<0.001) and in patients who had a injection before 12:30 PM (P<0.001). It decreased in higher BMI (P<0.001) and in patients diagnosed with lung cancer (P<0.05) In multivariable results, BAT activation was significantly increased in patients under 50 years (P<0.001), in females (P<0.001) and in lower outdoor temperature below 14.5℃ (P<0.001). It was significantly decreased in higher BMI (P<0.05). Conclusion A retrospective study of factors affecting BAT activation in patients who underwent PET/CT scan for 2 years at the National Cancer Center was conducted. The results confirmed that BAT was significantly activated in normal-weight women under 50 years old who underwent PET/CT scan in weather with an outdoor temperature of less than 14.5℃. Based on this result, the patient applied to the factor can be identified in advance, and it is thought that it will help to reduce BAT activation through several studies in the future.