• The Journal of Engineering Geology
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• v.21 no.2
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• pp.163-178
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• 2011

A test borehole was drilled in the Cheongwon area to investigate the relationship between geochemical environment and the natural occurrence of radioactive materials (uranium and Rn-222) in borehole groundwater. The borehole encountered mainly biotite schist and biotite granite, with minor porphyritic granite and basic dykes. Six groundwater samples were collected at different depths in the borehole using the double-packed system. The groundwater pH ranges from 5.66 to 8.34, and the chemical type of the groundwater is Ca-$HCO_3$. The contents of uranium and Rn-222 in the groundwater are 0.03-683 ppb and 1,290-7,600 pCi/L, respectively. The contents of uranium and thorium in the rocks within the borehole are 0.51-23.4 ppm and 0.89-62.6 ppm, respectively. Microscope observations of the rock core and analyses by electron probe microanalyzer (EPMA) show that most of the radioactive elements occur in the biotite schist, within accessory minerals such as monazite and limenite in biotite, and in feldspar and quartz. The high uranium content of groundwater at depths of -50 to -70 m is due to groundwater chemistry (weakly alkaline pH, an oxidizing environment, and high concentrations of bicarbonate). The origin of Rn-222 could be determined by analyzing noble gas isotopes (e.g., $^3He/^4He$ and $^4He/^{20}Ne$).

• Applied Microscopy
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• v.40 no.3
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• pp.125-132
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• 2010

Captured specimens of the lesser white-toothed shrew, Crocidura suaveolens were classified into three age classes by tooth wear and seasonal variations of reproductive organs were investigated. Molars of juveniles had not tooth wear and the height of the third molars were lower than the first and second molars, young adults had smooth tooth wear and the third molars reached to the first and second molars, and old adults had heavy tooth wear and the third molars also reached to the first and second molars. On the basis of histological examination, seasonal variation of breeding was confirmed that breeding season of adult males was from early February to early October, having a peak of the breeding in April and July, and non-breeding season was from in the middle of October to late January. Young and old adult males of the breeding season had large testes with enlarged seminiferous tubules filling with numerous germ cells and expanded caudal epididymides with a vast number of spermatozoa, Young and old adult males of the non-breeding season had the small testes with the extremely slender seminiferous tubules filling with only spermatogonia and the reduced caudal epididymides without spermatozoa. Males weighing more than 3.9 g in the body weight and 0.013 g in the testis and epididymis weight reached sexual maturation in breeding season, and the females weighing more than 3.8 g in body weight of the breeding season were pregnant condition having 5~6 litters or had the Graafian follicles and the corpus lutea in the ovary.

• Journal of Science Education
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• v.38 no.3
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• pp.670-690
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• 2014

The purpose of this study was to analyze paper and pencil test items of life science I in high school to diagnose problems of the test items developed by teachers, and to provide some implication for better assessment. 690 selection-type items and 162 supply-type items in life science I were collected from 10 general high schools. In the analysis of test items, the ratio of the selection-type item and the supply-type item was 81:19 in the number of items based on item type, while the ratio was 74.4:25.6 in the distribution of marks, indicating that the distribution of marks compared to the number of items was higher in the supply-type items. In the analysis by the Bloom's revised taxonomy of educational objectives, the items of 'conceptual knowledge' in the knowledge and those of 'understanding' in the cognition process were shown most in both the selection-type item and the supply-type item. In the analysis by the science assessment frameworks of NAEA, the items of 'knowledge' were shown 9 times more than those of 'inquiry'. When compared to the level of difficulty presented in the two-way specification table and the percentage of correct answers in the selection-type item, the concurrence was 41.5%. When compared to the ratio of number of items based on the item type of the supply-type items, the short-answer items were 34.0%, the descriptive items were 61.1%, and the drawing items were 4.9%. The drawing items were mainly developed in the unit of 'Cells and Continuity of Life'. When the descriptive items were classified by the acceptance of response, all the items were 'response restricted' type, and the items of 'restricted in content range' type among them were highest. When the items were classified by presentation of data, the items of 'presentation of data' type were highest(65.4%), and when classified by type of question, the items of 'knowledge description' type were highest(80.4%). In conclusion, it is needed to develop items belonging to 'inquiry' area more in the school, and to increase the ratio of the descriptive items, presenting various types of items.

• Journal of Science Education
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• v.38 no.3
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• pp.641-656
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• 2014

This study aimed at analyzing visual materials included in school science textbooks, specifically the textbooks for first semester courses of 3rd to 6th graders. The purpose was to provide directions for future textbooks by understanding the functions of the images in both pedagogical and social perspectives as well. The study was conducted by investigating the types, roles and socio-semiotic features of the images in science textbooks. The results were as follows. Firstly, the most used types of images in 2007 curriculum textbooks were photographs and drawn pictures. Uses of other visual aids than above were extremely rare. It was also found that as the educational level rises, the use of images for decorative functions drastically declined. The majority of the images were used in providing supplementary explanations or examples. This implies that the images effectively play the role of helping science education. In addition, more use of worksheets images was found, indicating that as educational level increases, students participate more actively in research sessions or data analysis. In socio-semiotic perspective, visual images showed high accessibility to students in 'Type of visual image', 'Function of visual image', 'Distance of shot', 'Horizontal angle of shot', 'Color moduation'. It was implied that there will a close correlation between the type, role and the socio-semiotic characteristics of visual images in textbooks. For example, photograph-type visuals were mostly used as supplementary references. And when applying the socio-semiotic analysis to photograph-type visuals, they showed 'real type', 'narrative-metaphor type', and 'shadow effect' among socio-semiotic features. Such correlations implied that knowing the type of the visual image may help determining the role of the image in the textbook to some extent, and also corresponding socio-semiotic characteristics. As a result, it was possible to infer how accessible certain visual images are to students. The above results have implications for the effective use of visual images in future textbooks.

• Proceedings of the Korean Statistical Society Conference
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• 2005.11a
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• pp.117-120
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• 2005

인구주택총조사는 국가통계의 가장 기본이 되는 자료를 생산하는 조사로 거의 대부분의 나라에서 전수조사방식으로 정기적으로 시행해왔다. 그러나 최근 들어 일부 국가, 특히 선진국에서 응답거부가 늘고, 조사대상을 접촉하기 어려운 등 조사환경이 나빠지고 있다. 아울러 조사비용이 급격하게 증가하고 있다. 이에 각 국의 통계청에서는 이러한 상황을 인구센서스에 대한 '근본적인 도전'으로 간주하고 있다(Jensen, 2000). 심지어 독일이나 네델란드에서는 조사환경의 악화로 1990년대 이후 인구센서스를 중단한 상태이다(Bierau, 2000). 조사환경의 악화는 조사의 포괄성과 신뢰성에 대한 문제를 야기한다. 선진국들과 마찬가지로 우리나라에서도 조사환경이 빠른 속도로 악화되고 있다. 더욱이 우리의 경우 읍면동사무소 기능축소로 말미암아 과거 인구주택총조사에서 실제 조사에 도움을 주었던 행정지원이 없어짐에 따라 앞으로 조사의 어려움은 더욱 커질 것으로 보인다. 이렇듯 악화되는 조사환경변화에 대응하여 선진 국가에서는 다양한 형태의 인구센서스방식들이 모색되고 있다. 많은 나라들이 순환형 센서스보다는 행정자료를 인구주택총조사에 활용하는 방안을 모색하고 있으며, 덴마크나 핀란드 등 일부 국가에서는 이미 전혀 조사를 하지 않고 행정자료로 대부분의 인구센서스 통계를 생산하고 있다(Harala, 1996; Gaasemyr, 1999; Laihonen, 1999), 많은 나라들이 행정자료를 활용한 인구센서스 방식을 선호하는 데는 또 다른 이유가 있다. 자료의 측면에서 보면, 행정자료를 활용할 경우 매년 인구센서스 통계를 생산할 수 있다. 실제로 현재 덴마크와 핀란드는 인구센서스에 준하는 통계를 매년 생산하고 있다. 또한 이러한 자료를 바탕으로 지역통계 수요에 즉각 대처할 수 있다. 더 나아가 이와 같은 통계는 전 국민에 대한 패널자료이기 때문에 통계적 활용의 범위가 방대하다. 특히 개인, 가구, 사업체 등 사회 활동의 주체들이 어떻게 변화하는지를 추적할 수 있는 자료를 생산함으로써 다양한 인과적 통계분석을 할 수 있다. 행정자료를 활용한 인구센서스의 이러한 특징은 국가의 교육정책, 노동정책, 복지정책 등 다양한 정책을 정확한 자료를 근거로 수립할 수 있는 기반을 제공한다(Gaasemyr, 1999). 이와 더불어 행정자료 기반의 인구센서스는 비용이 적게 드는 장점이 있다. 예를 들어 덴마크나 핀란드에서는 조사로 자료를 생산하던 때의 1/20 정도 비용으로 행정자료로 인구센서스의 모든 자료를 생산하고 있다. 특히, 최근 모든 행정자료들이 정보통신기술에 의해 데이터베이스 형태로 바뀌고, 인터넷을 근간으로 한 컴퓨터네트워크가 발달함에 따라 각 부처별로 행정을 위해 축적한 자료를 정보통신기술로 연계${cdot}$통합하면 막대한 조사비용을 들이지 않더라도 인구센서스자료를 적은 비용으로 생산할 수 있는 근간이 마련되었다. 이렇듯 행정자료 기반의 인구센서스가 많은 장점을 가졌지만, 그렇다고 모든 국가가 당장 행정자료로 인구센서스를 대체할 수 있는 것은 아니다. 행정자료로 인구센서스통계를 생산하기 위해서는 각 행정부서별로 사용하는 행정자료들을 연계${cdot}$통합할 수 있도록 국가사회전반에 걸쳐 행정 체제가 갖추어져야 하기 때문이다. 특히 모든 국민 개개인에 관한 기본정보, 개인들이 거주하며 생활하는 단위인 개별 주거단위에 관한 정보가 행정부에 등록되어 있고, 잘 정비되어 있어야 하며, 정보의 형태 또한 서로 연계가 가능하도록 표준화되어있어야 한다. 이와 더불어, 현재 인구센서스에서 표본조사를 통해 부가적으로 생산하는 경제활동통계를 생산하기 위해서는 개인이 속한 사업체를 파악할 수 있도록 모든 사업체가 등록되어 있고, 개인의 경제활동과 관련된 각종 정보들이 사업체에 잘 기록 및 정비되어 있어야 한다. 따라서 행정자료 기반의 인구센서스통계생산은 단지 국가의 통계뿐만 아니라 행정조직과 행정체계를 정비하고, 개인과 사업체의 등록체계를 정비하며, 사업체의 개인에 관한 정보를 정비하여 표준화하는 막대한 작업을 수반한다. 이런 이유에서 대부분의 국가들은 장래에 행정자료 기반의 인구센서스통계생산을 목표로 하되, 당장은 행정자료를 인구센서스에 보조적 수단을 사용하는 데 노력을 기울이고 있다. 우리나라의 경우 행정자료를 인구주택총조사에 활용할 수 있는 몇 가지 중요한 기반을 갖추고 있다. 첫째, 1962년부터 시행한 주민등록제도가 있다. 주민등록제도는 모든 국민 개개인을 파악할 수 있는 주민등록번호를 갖추고 있으며 40년 이상 제도화되어 오류가 거의 없는 편이다. 둘째, 세계 10위권 내에 들 정도로 높은 우리나라의 정보화 수준과 2000년부터 시작된 전자정부사업으로 행정자료를 연계${cdot}$통합할 수 있는 기반이 잘 갖추어져 있다. 반면, 우리나라 행정자료 가운데 주거(생활)단위와 사업체를 파악할 수 있는 자료는 매우불완전하다. 대표적으로 인구센서스통계의 주요한 단위인 가구를 파악할 수 있는 수준으로 주소체계가 정비되어 있지 않으며, 많은 사업체, 특히 소규모 사업 가운데 등록되어 있지 않거나 등록오류가 많은 편이다. 이외에도 과세대장, 토지대장 등 많은 행정자료가 아직은 불완전하여 이들을 직접 연계하기에 어렵다. 행정자료를 연계하기 위해서는 모든 자료를 정비하고 표준화하여 실제 행정에 활용하여야 하기 때문에 행정적으로 많은 노력과 시간이필요하다. 따라서 현재는 손쉬운 부분에서부터 인구주택총조사에 행정자료를 활용하고, 앞으로 활용 과정을 거치면서 행정자료를 정비하고 표준화하는 장기적인 방안을 마련할 필요가 있다.

• Korean Security Journal
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• no.60
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• pp.33-61
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• 2019

It is quite difficult to actually prove the effectiveness of so-called target-hardening, one of the various strategies used to reduce crime, one of the serious problems in society recently. In particular, three to five minutes is often used as golden time for intruders to give up or stop, which is based on foreign and some indirect research cases in Korea, but there were no studies that more directly identified the average break-in operation time or the abandonment time based on the elapsed time when the shield hardware resists intruders. This study was the first of its kind in Korea to investigate and verify samples of 90 inmates of break-in burglars who were imprisoned in August 2018 by profiling the average criminal experience, education level, age, height and weight of typical Korean professional break-in thieves, and specific criminal methods, average break-in operation time, and the criteria for giving up if not breached. According to the analysis results, in the survey on the number of pre-invasion theft crimes by intruders, many of the respondents who participated in the survey were criminals of professional invasions, and by their physical characteristics, there was not much difference from ordinary adult men. Residential facilities were the highest in the world, followed by commercial and educational facilities. According to the survey on the types of facilities that committed intrusion into residential facilities, it was not safe to say that single-family housing accounted for the largest portion of single-family housing, multi-family housing, apartment high-rise (more than three stories), and apartment low-rise (more than one to three stories) among residential facilities, and that the ratio of apartment high-rise was higher than expected. Based on the average time required to break into a place for an intrusion crime, it is assumed that the psychological time worked in a place where the break-in was difficult, since the break-in was not performed while measuring the time of the break-in operation. In the case of time to give up a crime, more than half of the respondents said they would give up the crime even in less than four minutes, suggesting that a significant number of intrusive crimes can be prevented even if the facility has four minutes of intrusion resistance. This proves that most intruders will give up the break-in if the break-in resistance performance of the security facility is exercised for more than five minutes.

• Radiation Oncology Journal
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• v.11 no.1
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• pp.51-58
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• 1993

We tried to establish the theoretical basis of clinical use of combined modality of hyperthermia and radiation therapy. For this purpose, we made an in vitro experiment in order to get the synergistic and/or additive effects on the cell killing of hyperthermia combined with radiation therapy by using the microwave-hyperthermia machine already installed at our department. In our experiment, we use two human cell lines: MKN-45 (adenocarcinoma of stomach) and K-562 (leukemia cell lines). In cases of combined treatments of hyperthermia and gamma-irradiation, the therapeutic effect was the highest in the simultaneous trial. Hyperthermia after gamma irradiation showed slightly higher therapeutic effect than that before irradiation without significant difference, but its effect was the same in the interval of 6 hours between hyperthermia and irradiation. The higher temperature and the longer treatment time were applied, the higher therapeutic effects were observed. We could observe the thermoresistance by time elapse at $43^{\circ}C$. When hyperthermia was done for 30 minutes at the same temperature, thermal enhancement ratio (TER) at DO. 01 (dose required surviving fraction of 0.01) were $2.5{\pm}0.08,\;3.75{\pm}0.18$, and $5.0{\pm}0.15\;at\;436{\circ}C,\;44^{\circ}C,\;and\;45^{\circ}C$ respectively in K-562 leukemia cell lines. Our experimental data showed that more cell killing effect can be obtained in the leukemia cell lines, although they usually are known to be radiosensitive, when treated with combined hyperthermia and radiation therapy. Furthermore, our data show that leukemia cell lines may have various intrinsic radiosensitivity, especially in vitro experiments. The magnitude of cell killing effect, however, will be less than that of MKN-45.

• Radiation Oncology Journal
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• v.18 no.1
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• pp.51-58
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• 2000

Purpose :The effect of PTK inhibitors (herbimycin A and genistein) on the induction of radiation-induced apoptosis in Ph-positive KS62 leukemia cell line was investigated. Materials and Methods :K562 cells in exponential growth phase were irradiated with a linear accelerator at room temperature. For 6 MV X-ray irradiation and drug treatment, cultures were initiated at 2×106 cells/mL. The cells were irradiated with 10 Gy. Stock solutions of herbimycin A and genistein were prepared in dimethyl sulphoxide (DMSO). After incubation at 37$^{\circ}C$ for 0$\~$48 h, the extent of apoptosis was determined using agarose gel electrophoresis and TUNEL assay. The progression of cells through the cell cycle after irradiation and drug treatment was also determined with flow cytometry. Western blot analysis was used to monitor bel-2, bel-X$_{L}$ and bax protein levels. Results :Treatment with 10 Gy X-irradiation did not result in the induction of apoptosis. The HMA alone (500 nM) also failed to induce apoptosis. By contrast, incubation of K562 cells with HMA after irradiation resulted in a substantial induction of nuclear condensation and fragmentation by agarose gel electro-phoresis and TUNEL assay. Genistein failed to enhance the ability of X-irradiation to induce DNA fragmentation. Enhancement of apoptosis by HMA was not attributable to downregulation of the bel-2 or bel-X$_{L}$ anti-apoptotic proteins. When the cells were irradiated and maintained with HMA, the percentage of cells in G2/M phase decreased to 30$\~$40$\%$ at 48 h. On the other hand, cells exposed to 10 Gy X-irradiation alone or maintained with genistein did not show marked cell cycle redistribution. Conclusion : We have shown that nanomolar concentrations of the PTK inhibitor HMA synergize with X-irradiation in inducing the apoptosis in Ph (+) K562 leukemia cell line. While, genistein, a PTK inhibitor which is not selective for p210$^{bcr/abl}$ failed to enhance the radiation induced apoptosis in KS62 cells. It is unlikely that the ability of HMA to enhance apoptosis in K562 cells is attributable to bel-2 family. It is plausible that the relationship between cell cycle delays and cell death is essential for drug development based on molecular targeting designed to modify radiation-induced apoptosis.

• Radiation Oncology Journal
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• v.27 no.3
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• pp.120-125
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• 2009

Purpose: We wanted to present the preliminary results of intensity-modulated radiotherapy (IMRT) for the treatment of tonsillar cancer. Materials and Methods: We retrospectively analyzed 12 patients who underwent IMRT for tonsillar cancer at Asan Medical Center between November 2002 and February 2007. Seven patients (58%) received definitive treatment, and five (42%) were treated in the postoperative setting. Among the definitively treated patients, 6 patients received cisplatin-based chemotherapy regimens. Simultaneous modulated accelerated radiation therapy (SMART) was used in nine patients. The prescribed dose was 72 Gy at 2.4 Gy/fraction for the definitively treated cases and 61.6 Gy at 2.2 Gy/fraction for the postoperative cases. The median follow-up period was 34 months. Results: All twelve patients completed treatment without interruption, and eleven showed a complete response. One patient had persistent loco-regional disease after treatment. The three-year estimates of loco-regional control, disease-free survival and overall survival were 91.7%, 91.7%, and 100%. The worst acute mucositis was Grade 1 in four patients, Grade 2 in five patients, Grade 3 in two patients and Grade 4 in one patient. Grade 3 xerostomia was observed in six patients. Conclusion: Intensity-modulated radiotherapy was shown to be a safe and effective treatment modality for tonsillar cancer. Further studies with a larger number of patients and a longer follow-up period are needed to evaluate the ultimate tumor control and late toxicity of IMRT for treating tonsillar cancer.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.3 no.2
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• pp.59-70
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• 1998

Two-dimensional trend-vector model of sediment transport is first tested in the tidal flat of Garolim Bay, mid-western coast of the Korean Peninsula. Three major parameters of surface sediment, i.e., mean grain size, sorting and skewness, are used for defining the best-fitting transport trend-vector on the sand ridge and muddy sand flat. These trend vectors are compared with the real transport directions determined from morphology, field observation and bedforms. The 15 possible cases of trend vectors are calculated from total sediments. In order to find the role of coarse sediments, trend vectors from sediments coarser than < 4.5 ${\phi}$, (sand size) are separately calculated from those of total sediments. As compared with the real directions, the best-fitting transport-vector model is the "case M" of coarse sediments which is the combined trend vectors of two cases: (1) finer, better sorted and more negatively skewed and (2) coarser, better sorted and more positively skewed. This indicates sand-size grains are formed by simpler hydrodynamic processes than total sediments. Transported sediment grains are better sorted than the source sediment grains. This indicates that consistent hydrodynamic energy can make sediment grains better sorted, regardless of complicated mechanisms of sediment transport. Consequently, both transported vector model and real transported direction show that the source of sediments are located outside of bay (offshore Yellow Sea) and in the baymouth. These source sediments are transported through the East Main Tidal Channel adjacent the baymouth. Some are transported from the subtidal zone to the upper tidal flat, but others are transported farther to the south, reaching the south tidal channel in the study area. Also, coarse sediment grains on the sand ridge are originally from the baymouth, and transported through the subtidal zone to the south tidal channel. These coarse sediments are moved to the northeast, but could not pass the small north tidal channel. It is interpreted that the great amount of coarse sediments is returned back to the outside of the bay (Yellow Sea) again through the baymouth during the ebb tide. The distribution of muddy sand in the northeastern part of study area may result from the mixing of two sediment transport mechanisms, i.e., suspension and bedload processes. The landward movement of sand ridge and the formation of the north tidal channel are formed either by the supply of coarse sediments originating from the baymouth and outside of the bay (subaqueous sand ridges including Jang-An-Tae) or by the recent relative sea-level rise.