공명현상과 파워도플러를 이용한 유방조직 팬텀의 미세 석회화 병변 진단

김정구,하명진,Kim, Jeong-Koo,Ha, Myeung-Jin 한국음향학회 2008 韓國音響學會誌 Vol.27 No.2

유방초음파 검사는 유방암 검사에 있어 유방촬영술에 비하여 많은 장점이 있으나, 미세석회화 발견에는 적합하지 않은 단점이 있다. 이에 유방초음파 검사에서 기존의 7.5 MHz 선형 탐촉자를 사용하여 파워도플러와 매질의 공명현상을 이용한 유방조직 석회화 병변을 관측할 수 있는 방법을 연구하였다. 먼저 gelatin을 이용하여 유방조직 팬텀을 제작하였으며, 외부 진동을 변화시켜 가며 석회화 병변을 관측하였다. 유방조직 팬텀 안에 주입된 석회화는 주변 조직과 다른 공명을 일으키면서 외부진동에 따라 음향공명의 정도가 파워도플러의 ROI 영역 내의 색상의 밝기와 영역의 차이로 나타내었다. 낮은 주파수 영역에는 음향공명이 거의 나타나지 않았으며, 약 $300{\sim}600\;Hz$ 사이에서 일정한 플래토우 영역을 나타내었으며, 이후 주파수가 증가함에 따라 색상이 사라짐을 확인하였다. Breast ultrasound has many advantages over mammography but suffers from a shortcoming of being not suitable in detecting microcalcification. We studied on a method based on acoustic resonance and power Doppler to detect calcification of breast tissue using a typical 7.5 MHz linear probe used in breast ultrasound examination. We first constructed a breast tissue phantom made of gelatin and then observed calcified legions as external vibrations varied. Calcification injected to the breast tissue phantom being resonated different from the surrounding medium, and its acoustic resonance driven by external vibrations was visualized by differences for color brightness and area in ROI of power doppler. In low frequency regions, the acoustic resonance almost not appeared and showed a plateau in $300{\sim}600\;Hz$ and the color vanished as the frequency further increased.

휴먼 브랜드에 대한 강한 애착의 선행 요인과 삶의 만족에 미치는 영향

김정구 ( Chung Koo Kim ),전미나 ( Mi Na Jun ),김미예 ( Mi Yea Kim ),한정수 ( Jeong Soo Han ) 한국소비자학회 2010 소비자학연구 Vol.21 No.4

현대의 유명인은 단순히 유명한 연예인이나 스포츠 스타가 아니라 그 자체로 하나의 휴먼브랜드로써 대중들의 마음속에 자리 잡고 있다. 이런 휴먼브랜드의 역할이 확대되고 중요해지면서 많은 사람들이 이들에게 사랑과 관심을 보내고 또 강한 애착을 형성하기도 한다. 따라서 본 연구는 휴먼브랜드에 대해서 사람들이 가지는 강한 애착의 선행요인은 무엇인지, 그리고 이러한 애착이 삶에 어떻게 영향을 미치는지를 실증분석하기 위해 연구 1과 연구 2로 나누어서 진행하였다. 연구 1에서는 휴먼브랜드에 대한 강한 애착의 선행요인으로써 A-R-C(자율성, 관계성, 유능감) 욕구 충족이 애착 형성에 미치는 영향과 휴먼브랜드에 대한 애착의 사람들의 삶의 만족에 미치는 영향을 알아보았다. 연구 2에서는 기존연구를 기반으로 휴먼브랜드를 일반 유명인(Celebrity)과 영웅적 유명인(Hero)로 분류하였다. 그리고 A-R-C 욕구충족이 각각의 휴먼브랜드에 대한 강한 애착에 어떻게 영향을 미치는지, 각각의 휴먼브랜드에 대한 애착이 사람들의 삶의 만족에 어떻게 차별적으로 영향을 미치는지 알아보았다. 본 연구의 결과를 간단히 요약하면, 첫째, A-R-C (자율성, 관계성, 유능감)욕구 충족이 휴먼브랜드애착에 긍정적인 영향을 끼친다는 것으로 나타났다. 둘째, 모든 휴먼브랜드에 대한 애착은 삶의 만족에 영향을 미치는 것은 아니지만, 휴먼브랜드를 분류하였을 때 일반 유명인에 대한 애착은 삶의 만족에 영향을 끼치지 못하고 영웅적 유명인은 삶의 만족에 긍정적인 영향을 끼친다는 것으로 나타났다. 본 연구의 학문적 공헌이 있다면, 첫째, A-R-C 욕구 충족이 휴먼브랜드에 대한 애착에 모두 유의한 영향을 끼친다는 것을 처음으로 증명한 연구라고 할 수 있다. 둘째, 휴먼브랜드에 대한 애착이 개인적 차원의 삶의 질에 긍정적인 영향을 끼친다는 것을 처음으로 검증하였다. 셋째, 휴먼브랜드를 분류함으로써 영향력의 차이를 증명하고 영웅적 유명인의 역할의 중요성을 시사한다. TIME and FORBES which are well-known worldwide media announce most influential and popular 100 people every year. Every time they announce the list, world shows interest in who would be in the list every year. This new social phenomenon indicates that people perceive well-known persona like TV stars or sports stars etc. as human brands. As the role of these human brands is getting more important, people tend to develop strong attachment toward them. Another notable social phenomenon in these days is people`s pursuit of satisfaction with life or social well-being. People want to increase quality of life by having quality time with family and friends, and also attachment with celebrities, sports stars, and so on. Thus, the central purposes of this article are to address why people develop attachments toward human brands and how the attachment toward human brands affects quality of life. In order to achieve these goals, we conducted 2 studies. In study 1, we examined how the A-R-C needs (autonomy, relatedness and competence needs) fulfillment as antecedents affects strong attachment toward human brands and how the attachment toward human brands affects life satisfaction. In study 2, based on previous researches we divided human brands into two types which are heroes and celebrities. Heroes are defined as people who have considerable and lasting importance at both society and individual level and celebrities are defined as people who are well-known but who have less or no impact at both society and individual level for a shorter period time, Afterward we examined how A-R-C needs fulfillment affects attachment toward each types of human brands and how attachment toward each types of human brands affects life satisfaction. Major findings from study 1 are that A-R-C needs fulfillment has positive impact on developing strong attachment toward human brands and the attachment toward human brands also has positive impact on life satisfaction in general. That is, more human brands fulfill people`s A-R-C needs, stronger attachment people develop toward human brands and stronger attachment people develop toward human brands, more satisfaction people feel about life. Major findings from study 2 are that A-R-C needs fulfillment has positive impact on developing attachment toward both heroes and celebrities. However, only the attachment toward heroes has positive impact on life satisfaction while the attachment toward celebrities has no impact on life satisfaction. This result suggests the difference between heroes and celebrities and emphasizes importance of role heroes play in increasing quality of life. In terms of major findings combined from study 1 and 2, the present research has three contributions. First, in contrast to previous research on strong attachment toward human brands that had revealed only autonomy and relatedness needs fulfillment positively affects forming strong attachment toward human brands(Thomson 2006, Ahn and Lee 2010), our research empirically proved that all of the A-fl-C needs fulfillment has positive impact on developing strong attachment toward human brands for the first time. Second, our research empirically analyzed life satisfaction at personal level as the outcome variables of attachment toward human brands. In contrast to most researches on brand attachment that focused on brand commitment, brand loyalty and so on at corporate or products level, our research showed meaningful results by focusing on quality of life rather than products. Third, our research emphasized role of heroes by dividing human brands into celebrities and heroes. The result of study 2 showed that the attachment toward heroes increases quality of life by having people feel more satisfaction about life while the attachment toward celebrities doesn`t. Thus, heroes who have considerable and lasting importance at both society and individual level can play very important role to increase quality of life. Although the present research gives considerable contributions, there are some limitations and further researches we would like to address. First, while our research shows that competence need fulfillment positively affects to develop strong attachment toward human brands, other studies showed different results. Therefore, more study would be necessary to find out the role of competence need fulfillment in forming attachment. Second, while heroes positively affect life satisfaction, celebrities does not. According to Frankl(1997), people pursue three types of value, entertainment, power, meaning. Of these three values Frankl(1997) suggested, entertainment and power values may represent short- term value that celebrities have while meaning value may represent long-term value that heroes have. Hence, further research should empirically study if there is relationship between values Frankl suggested and values that heroes and celebrities have. Third, although the present research assessed life satisfaction level as the outcome of attachment toward human brands, further research should adopt more comprehensive wellbeing index which is more detailed multidimensional scale to assess Quality of life as the outcome of attachment toward human brands.

현장교육 성공사례 : DIGITAL IC 의 실험 장치의 제작

김정구(Jeong Koo Kim) 대한공업교육학회 1979 대한공업교육학회지 Vol.4 No.1

단백질 알부민 수용액의 광대역 초음파 스펙트로스코피

김정구(Jeong-Koo Kim),배종림(Jong-Rim Bae) 대한방사선과학회(구 대한방사선기술학회) 2007 방사선기술과학 Vol.30 No.2

  알부민 수용액(pH 7)에 대한 초음파 흡수 메카니즘을 규명하기 위해 주파수 0.2~1,000㎒에 걸쳐 흡수특성측정을 하였다. 관측된 단백질 알부민 수용액의 흡수스펙트럼은 David-Cole함수의 거울상으로 가정한 완화시간의 분포함수와 일치하였다. 이 분포함수는 BSA분자의 수화평형에 의한 것이고 수화평형에 의해 넓은 주파수영역에 걸쳐 완화현상이 일어난다.   Ultrasonic absorption spectrum in bovine serum albumin aqueous solutions have been measured at 20℃ over the broad frequency range 0.2~1,000㎒ at pH 7. The absorption spectrum observed at neutral pH was successfully analyzed with the distribution of relaxation time assuming a mirror-image curve of the Davidson-Cole function. This distribution function suggests that hydration of BSA molecules is responsible for the absorption.

액정의 상전이 측정에 대한 초음파 spectroscopy 시스템의 적용

김정구(Jeong-Koo Kim),임청환(Cheong-Hwan Lim) 대한방사선과학회(구 대한방사선기술학회) 2004 방사선기술과학 Vol.27 No.4

A new measuring system for ultrasonic spectioscopy was constructed, utilizing PVDF [poly(vinylidene fluoride)] polymer films as wideband transducers In a test of its performance, this measuring system was successfully applied to study of the nematic-isotropic phase transition in MBBA(p-methoxybenzyli-dene-p-n-butylan iline) liquid crystal. We could be could that the phase transition in MBBA is 47℃, which is agree with the exciting optical method, The dependence of frequency on the phase transition was not observed, and but Maximum ultrasonic amplitude is measured for the resonance frequency 2㎒ in PVDF transducers, These results shows that the spectroscopy with PVDF transducers takes advantage of studying the transient phenomena When our apparatus is applied in medical purposes, It will be possible diagnostic for sickle-cell anemia and arterial sclerosis PVDF(poly(vinylidene fluoride)] 압전소자로 제작된 초음파 변환기를 이용하여 초음파 spectroscopy 측정시스템을 제작하였다. 이 장치를 이용하여 MBBA(p-methoxy benzylidene-p-n-butylaniline) 액정의 nematic-isotropic 상전이 현생을 관측한 결과 상전이 온도가 47℃임을 확인하였으며, 기존의 광학적 방법에 의해 관측된 값과 잘 일치하였다. 한편으로 상전이 정의 주파수 의존성을 확인하였으나 이는 관측되지 않았으며, 단지 PVDF 압전소자의 공진주피수인 2 ㎒에서 초음파의 진폭이 최대로 나타났으며, 다른 주파수에서는 진폭이 감소함을 알 수 있었다. 이와 같이 온도의 변화에 따른 액정의 상전이 현상을 초음파 감쇠의 변화로 확인하여 보았다. 이것은 액정의 상전이 메카니즘을 해석함에 있어 PVDF 초음파 변환기를 이용한 spectroscopy 측정 시스템은 매우 유용한 도구로 이용될 수 있음을 확인하였으며, 의료용으로 이용할 경우 겸상세포 빈혈증이나 동맥 경화증과 같은 질병 진단에 이용 가능하리라 여겨진다.

소아암 환자의 양성자치료 시 DIPS 촬영에 따른 피폭선량

김정수(Jeong-Soo Kim),김정구(Jeong-Koo Kim) 대한방사선과학회(구 대한방사선기술학회) 2011 방사선기술과학 Vol.34 No.1

소아암 환자에 대한 양성자치료 시 정밀한 자세재현 확인 및 종양의 위치파악을 위한 DIPS 촬영으로 인하여 발생하는 방사선 피폭에 관하여 확인하여 보았다. 2007년 3월부터 2009년 10월까지 일산의 K 암전문병원에서 양성자치료를 받은 50명의 소아암 환자를 대상으로 DIPS의 촬영조건을 비교 분석하였으며, 1회 DIPS 촬영 시 피폭선량은 전후 측면촬영에서 0.09~1.57 mGy로 측정 되었으며, 1일 DIPS 촬영이 가장 많은 소아암 환자는 뇌척수조사 환자로 23.55 mGy로 측정되었다. 전뇌조사 환자에서 1일 DIPS 촬영 시 피폭선량이 1.13 mGy로 1일 처방선량을 가장 많이 초과하였으며, 권고선량의 2%를 초과하지 않았다. 치료기간 중 DIPS 피폭선량이 가장 많은 환자는 전뇌조사 환자로 632.71 mGy로 이는 처방선량의 1.13%로 권고선량의 2%를 초과하지 않는 합당한 선량으로 나타났다. 소아암 환자에 대한 DIPS 촬영 시 피폭선량은 처방선량에 대하여 2%를 초과하지 않는 피폭선량으로 나타났지만, 방사선감수성이 높고 평균 잔여 수명이 긴 소아암 환자에게는 유전적 영향 등의 확률적 영향과 관련된 방사선 장해를 초래할 수 있음을 인식하여 소아암 환자의 DIPS 촬영에 대한 가이드라인 제시로 방사선 피폭을 최소화할 수 있는 방안을 마련해야 할 것으로 사료된다. We investigated the radiation exposure caused by DIPS, which is used to identify accurate repositioning and tumor location in pediatric cancer patients proton therapy. To compare and analyze DIPS condition, 50 pediatric cancer patients who underwent proton therapy were selected in Ilsan K cancer-specialized hospital from March 2007 to October 2009. For DIP exposure, 0.09~1.57 mGy is measured in AP and lateral directions and 23.55 mGy is measured in CSI patients. In whole brain patient, the amount of a day DIP exposure dose was 1.13 mGy. During treatment period, who exposed the biggest DIP dose are whole brain patients, 632.71 mGy is exposed. It is 1.13% of prescribed dose, represented dose is adequate because it is not exceeded 2% of recommended dose. Even though the exposed dose is not exceeded more than 2% of prescribed in DIP exposure, we should recognize the radiation damage and genetic influences to pediatric cancer patients, who is much sensitive to radiation and has longer mean residual life time. Therefore, DIPS guideline for pediatric cancer patients should be indicated to minimize the radiation exposure.

중재 시술용 기능성 기관-기관지 팬텀의 유용성

김태형(Tae-Hyung Kim),임청환(Cheong-Hwan Lim),김정구(Jeong-Koo Kim),김명수(Myeong-Soo Kim),최원찬(Won-Chan Choi),임진오(Jin-Oh Lim),이광종(Kwang-Jong Lee),박인애(In-Ae Park),김미옥(Mi-Ok Kim),정은미(Eun-Mi Jung),신령미(Ryung-Mi Shin) 대한방사선과학회(구 대한방사선기술학회) 2003 방사선기술과학 Vol.26 No.4

중재 시술용 기능성 기관-기관지 팬텀을 제작하고, 스텐트 삽입술을 시행하여 그 유용성을 평가하고자 한다. 중재 시술용 기능성 기관-기관지 팬텀은 실리콘으로 제작하였으며, 기관을 통하여 스텐트 삽입술이 가능하도록 삽입구를 제작하였다. 팬텀은 지점토를 이용하여 인체와 동일한 형태로 기관, 기관지 분지부와 양쪽 상부 기관지를 재현하였고, 사각형의 틀에 지점토를 고정시킨 후 액상의 실리콘을 채워 건조시킨 후 지점토를 제거하여 제작하였다. 인체, 동물, 팬텀에서 기관지스텐트 삽입 후 흉부 촬영 필름의 농도와 기관지 분지부의 각도를 측정하여 비교하였다. 기관지스텐트는 세선의 교차가 다른 2가지(X-type, Y-type) 형태를 삽입하였으며, 스텐트 삽입술 후 기관 상부, 기관 분지부, 좌기관지, 우기관지, 스텐트 삽입부의 필름농도를 측정하였다. 필름농도는 기관 상부의 경우, 인체 0.76(±0.011), 동물 0.97(±0.015), 팬텀 0.45(±0.016)이었고, 기관 분지부의 경우는 인체 0.51(±0.006), 동물 0.65(±0.005), 팬텀 0.65(±0.OO8)이었고, 우기관지의 경우는 인체 0.14(±0.OO8), 동물 0.59(±0.014), 팬텀 0.04(±0.007)이었고, 좌기관지의 경우는 인체 0.54(±0.004), 동물 0.54(±O.008)로 팬텀 0.08(±0.OO8)이었고, 스텐트 삽입부의 경우는 인체 0.54(±0.004), 동물 0.59(±0.011), 팬텀 0.04(±0.007)이었다. 기관 분지부가 이루는 각도는 인체의 좌기관지에서 42.6(±2.07)˚, 우기관지에시 32.8(±2.77)˚이었으며, 동물에서 각각 43.4(±2.40)˚, 34.6(±1.94)˚, 팬텀에서 각각 35(±2.00)˚, 50.2(±1.30)˚이었다. 본 연구팀이 제작한 기관-기관지 팬텀은 기관지 스텐트 삽입술의 재현이 가능하여 중재시술의 술기연습용이나 스텐트를 평가하기 위한 체외실험에 사용이 가능할 것으로 사료된다. To evaluate usefulness of a functional tracheobronchial phantom for interventional procedure. The functional phantom was made as a actual size with human normal anatomy used silicone and a paper clay mold. A tracheobronchial-shape clay mold was placed inside a square box and liquid silicone was poured. After the silicone was formed, the clay was removed. We measured film density and tracheobronchial angle at the human, animal and phantom, respectively. The film density of trachea part were O.76(±O.O11) in human, O.97(±O.015) in animal, O.45(±O.O16) in phantom. The tracheobronchial bifurcation part measured O.51(±O.OO6) in human, O.65(±O.OO5) in animal, O.65(±O.008) in phantom. The right bronchus part measured O.14(±0.008) in human, O.59(±0.014) in animal and O.O4(±O.OO7) in phantom. The left bronchus were O.54(±O.004) in human, O.54 (±0.008) in animal and O.08(±0.008) in phantom. At the stent part were O.54(±O.004) in human, O.59(±0.011) in animal and O.04(±0.007) in phantom, respectively. The tracheobronchial angle of the left bronchus site were 42.6(± 2.07)˚ in human, 43.4(±2.4O)˚ in animal and 35(±2.00)˚ in phantom, respectively. The right bronchus site were 32.8(±2.77)˚ in human, 34.6(±1.94)˚ in animal and 50.2(±1.30)˚ in phantom, respectively. The phantom was useful for in-vitro testing of tracheobronchial interventional procedure, since it was easy to reproduce.

DR 시스템에서 모드 변화에 따른 구리필터의 유용성 평가

김재겸(Kim Jae-Kyeom),김정구(Kim Jeong-Koo) 대한방사선과학회(구 대한방사선기술학회) 2021 방사선기술과학 Vol.44 No.1

This study confirmed the usefulness of the copper filter according to the mode change by comparing and analyzing the energy change according to the application of the copper filter and the change in effective dose and image quality according to the distance to the subject in the DR(Digital Radiography) system. The average energy increased when the copper filter was applied and the reduction rate by 50% of mAs was increased as the thickness of the copper filter increased according to the application of the 10 kVp rule in AEC mode. The effective dose decreased as the thickness increased when the copper filter was applied in AEC(Automatic Exposure Control) mode and manual mode according to the application of the 10 kVp rule, and the decrease rate decreased with increasing 10 kVp increments. As a result of analyzing the dicom images for AEC mode and manual mode with Image J. the PSNR(Peak Signal to Noise Ratio) values were approximate values of less than 30 dB for each mode and for each copper filter thickness. When the copper filter was applied, the average energy increased, so when the 10 kVp rule was applied, the mAs for each mode could be reduced, and the effective dose could also be reduced. However, as the distance and tube voltage increased, the reduction rate of mAs decreased, and the quality of the image was found to decrease when the copper filter was applied, but there was no difference in quality of the image when the copper filter thickness increased.

ATP meter를 이용한 초음파 탐촉자의 오염도 분류

하명진,김정구,Ha, Myeong-Jin,Kim, Jeong-Koo 대한방사선과학회 2020 방사선기술과학 Vol. No.

In this study, the contamination level was measured using an ATP meter using adenosine triphosphate bioluminescent material to find effective infection control to compensate for the disadvantages of the microbial culture method used for hygiene control of ultrasound probe. The convex probes were selected from six ultrasound probe in the hospital, and the samples were taken in real time before and after cleaning to check the contamination of the probe. In order to classify the pollution degree using the APT meter was classified by category. A total of 78 samples were collected from the ultrasound probe. When the pollution levels before and after cleaning were classified by category, 76.6% of the samples were classified into category 3·4 before cleaning, but they decreased to 23.3% after cleaning. 13.3% before cleaning was in category 1, but increased to 43.3% after cleaning. By classifying the pollution level, it was confirmed that the pollution level was significantly reduced by category. Until now, there was no suitable criterion for determining the contamination level by using ATP meter in medical machines where sample area is small and reused. In this study, criteria for each category were set to measure the contamination level of ATP meter suitable for small sample area such as ultrasound probe, so that contamination level could be determined in real time at the site. Therefore, it is considered that hygiene management for ultrasound probe can be more actively performed.

Manufacturing a Functional Bolus Using a 3D printer in Radiation Therapy

이이성,김정구,Lee, Yi-Seong,Kim, Jeong-Koo Korean Society of Radiological Science 2020 방사선기술과학 Vol. No.

Commercial plate bolus is generally used for treatment of surface tumor and required surface dose. We fabricated 3D-printed bolus by using 3D printing technology and usability of 3D-printed bolus was evaluated. RT-structure of contoured plate bolus in the TPS was exported to DICOM files and converted to STL file by using converting program. The 3D-printed bolus was manufactured with rubber-like translucent materials using a 3D printer. The dose distribution calculated in the TPS and compared the characteristics of the plate bolus and the 3D printed bolus. The absolute dose was measured inserting an ion chamber to the depth of 5 cm and 10 cm from the surface of the blue water phantom. HU and ED were measured to compare the material characteristics. 100% dose was distributed at Dmax of 1.5 cm below the surface when was applied without bolus. When the plate bolus and 3D-plate bolus were applied, dose distributed at 0.9 cm and 0.8 cm below the surface of the bolus. After the comparative analysis of the radiation dose at the reference depth, differences in radiation dose of 0.1 ~ 0.3% were found, but there was no difference dose. The usability of the 3D-printed bolus was thus confirmed and it is considered that the 3D-printed bolus can be applied in radiation therapy.