• Korean Journal of Forensic Psychology
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• v.11 no.1
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• pp.89-115
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• 2020

Traditional deception detection methods had examined the difference of one's autonomic physiological responses through asking crime-related and crime-unrelated questions. There has been a continuing controversy regarding the accuracy and validity of the test, and thus, many researchers were motivated to explore and develop alternative efficient methods of detection in which one of them is known as P300-based Complex Trial Protocol (CTP). The P300-based CTP detects deception through comparing the P300 amplitudes between probe and irrelevant stimuli and is known as a counterstrategy of countermeasures. However, many previous studies have used countermeasures created from Rosenfeld et al.'s work (2008). The present study initially conducted a survey asking open-ended questions about the countermeasure use to acquire participant-oriented countermeasures for the main experiment. Then, the study aimed to evaluate whether the CTP can accurately detect deception even in the use of survey-based countermeasures. We firstly selected a set of participant-oriented countermeasures through survey questions. Then, a total of 50 participants were divided into three groups (innocent, guilty, and countermeasures) and performed the CTP. Those assigned to the countermeasures group covertly performed mental countermeasures during the CTP. The results of P300 amplitude analysis revealed that the guilty group's P300 amplitude of probe stimuli was significantly larger than that of irrelevant stimuli. Countermeasures group also had a significantly larger P300 amplitude for probe stimuli compared to irrelevant stimuli, even in the use of countermeasures. The results of bootstrapped amplitude difference (BAD) showed a detection accuracy rate of 81.25%, 82.35%, 82.35% for the innocent, guilty, and countermeasures groups, respectively. These findings demonstrate that the CTP can obtain a high detection rate in participant-oriented countermeasures and suggest the potential use of the CTP in the field.

• Korean Journal of Forensic Psychology
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• v.11 no.2
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• pp.173-190
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• 2020

The purpose of this study is to verify whether it is possible for participants to discriminate between innocent and guilty suspects when they are exposed to criminal information utilizing an autobiographical implicit association test (aIAT). A total of 49 college students were randomly assigned to guilty group, innocent-aware group, or innocent-unaware group. Participants performed an aIAT to detect suspects after performing either mock crime or control task. It was verified that innocent suspect and guilty suspect exposed with crime information could be distinguished through D-score and reaction time, converted to symbolize strength of the association between guilty sentences, innocent sentences, and truth sentences. As a result of the analysis, guilty group showed significantly higher D-score than both innocent-aware group and innocent-unaware group. guilty group also showed faster response time in true-guilty condition than true-innocent condition. This shows that the association of true-guilty conditions is stronger than that of true-innocent conditions. On the other hand, the innocent-aware group showed a faster response time in the true-innocent condition than the true-guilty condition, and innocent-unaware group showed no significant difference between the two conditions. Through this, it was confirmed that innocent suspects exposed to criminal information can be discriminated according to the aIAT pattern, which has a faster reaction rate to the truth and innocence union than the guilty group. This study confirmed that suspects exposed to criminal information can be effectively discriminated using aIAT, and further suggests the usefulness and potential of aIAT in the field of lie detection.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.33 no.2
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• pp.295-303
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• 2023

As the cloud computing market grows, a variety of cloud services are now reliably delivered. Administrative agencies and public institutions of South Korea are transferring all their information systems to cloud systems. It is essential to develop security solutions in advance in order to safely operate cloud services, as protecting cloud services from misuse and malicious access by insiders and outsiders over the Internet is challenging. In this paper, we propose a zero trust model for cloud storage services that store sensitive data. We then verify the effectiveness of the proposed model by operating a cloud storage service. Memory, web, and network forensics are also performed to track access and usage of cloud users depending on the adoption of the zero trust model. As a cloud storage service, we use Amazon S3(Simple Storage Service) and deploy zero trust techniques such as access control lists and key management systems. In order to consider the different types of access to S3, furthermore, we generate service requests inside and outside AWS(Amazon Web Services) and then analyze the results of the zero trust techniques depending on the location of the service request.

• Journal of Korean Society of Forest Science
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• v.112 no.4
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• pp.554-560
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• 2023

To prevent illegal timber distribution, DNA markers have been used to identify the species and origin. However, extracting high-quality DNA from timber is difficult because of its physical and chemical properties. In this study, we investigated whether the age of timber tissue influences the yield of DNA extraction and the success rate of polymerase chain reaction (PCR) to understand the relationship between the establishment time of the wood annual ring and the extracted DNA concentration (ng/μl), purity (A260/A280), and PCR success rate (%) from pinewood, a major Korean domestic species. According to the results, it was observed that as the distance from the cambium increased, indicating that the tissue was older, the concentration and purity of the extracted DNA decreased significantly. For the trnM-trnV (285 bp) and rpoC1 (298 bp) regions, the PCR success rate was 100%. However, for the rbcL (1.3 kb) region, the PCR success rate was 66.67%. Moreover, PCR amplification of the rbcL region failed at all points older than 30 years. Thus, it is deduced that as time passes, along with the decay of timber cells, DNA is degraded, leading to a decrease in DNA concentration, purity, and PCR success rate. The results of this study are expected to be beneficial for future applications, such as the species identification of timber, providing valuable insights and potential utilization in this field.

• Korean Chemical Engineering Research
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• v.57 no.5
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• pp.637-651
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• 2019

In the event of a major accident such as an explosion in a refinery or a petrochemical plant, it has caused a serious loss of life and property and has had a great impact on the insurance market. In the case of catastrophic incidents occurring in process industries such as refinery and petrochemical plants, only the proximate causes of loss have been drawn and studied from inspectors or claims adjustors responsible for claims of property insurers, incident cause investigators, and national forensic service workers. However, it has not been done well for conducting root cause analysis (RCA) and identifying the factors that contributed to the failure and establishing preventive measures before leading to chemical plant's catastrophic incidents. In this study, the criteria of warning signs on CCPS catastrophic incident waning sign self-assessment tool which was derived through the RCA method and the contribution factor analysis method using the swiss cheese model principle has been reviewed first. Secondly, in order to determine the major incident warning signs in an actual chemical plant, 614 recommendations which have been issued during last the 17 years by loss control engineers of global reinsurers were analyzed. Finally, in order to facilitate the assessment index for catastrophic incident warning signs, the criteria for the catastrophic incident warning sign index at chemical plants were grouped by type and classified into upper category and lower category. Then, a catastrophic incident warning sign index for a chemical plant was developed using the weighted values of each category derived by applying the analytic hierarchy process (pairwise comparison method) through a questionnaire answered by relevant experts of the chemical plant. It is expected that the final 'assessment index for catastrophic incident warning signs' can be utilized by the refinery and petrochemical plant's internal as well as external auditors to assess vulnerability levels related to incident warning signs, and identify the elements of incident warning signs that need to be tracked and managed to prevent the occurrence of serious incidents in the future.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.4
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• pp.579-585
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• 2015

The objective of this study was to investigate the quality characteristics of coffee soaked in Morus bombycis extract. Green coffee beans were soaked in M. bombycis extract for 2, 4, and 6 hours (sample codes: 2H, 4H, and 6H) at $4^{\circ}C$. Soaked green beans were dried and roasted for coffee extraction. Two controls, roasted with the same amount of heat (C1) and showed the same weight after roasting (C2), were used. Physicochemical characteristics (pH, total acidity, color, browning index, and total soluble solids), DPPH free radical scavenging activity (DPPH), ferric-reducing antioxidant power (FRAP), oxygen radical absorbance capacity (ORAC), total polyphenol content (TPC), and total flavonoid content (TFC) were investigated. Lower pH and higher total acidity were observed in 2H, 4H, and 6H (P<0.05), supporting evidence of sour taste. There were significant differences in DPPH between the controls (45.51~47.02%) and samples (50.67~55.25%, P<0.05), although 2H and 6H did not show significantly higher DPPH than the controls. 2H, 4H, and 6H showed significantly higher FRAP values ($0.320{\sim}0.331\;FeSO_4{\cdot}7H_2O\;mM\;FeSO_4/g$) than controls ($0.265{\sim}0.271\;mM\;FeSO_4/g$). ORAC values of samples [1,062.86~1,153.68 mM trolox equivalent (TE)/g] were significantly higher than those of controls (689.40~942.12 mM TE/g). 2H, 4H, and 6H showed significantly higher TPC [24.27~26.07 mg gallic acid equivalent (GAE)/g] and TFC [3.75~4.28 mg quercetin equivalent (QE)/g] than controls (19.79~22.77 mg GAE/g and 1.07~1.95 mg QE/g, respectively) (P<0.05). M. bombycis extracts soaked into green coffee beans showed polyphenol compounds from green coffee beans. Consumer acceptance of 4H (5.12) was the highest, followed by C2 (4.92). C1 (4.14) showed the lowest consumer acceptance. Consumers were segmented into two groups, those who preferred M. bombycis extract-soaked coffee (approximately 61%) and controls (approximately 39%).

• Tuberculosis and Respiratory Diseases
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• v.58 no.4
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• pp.352-358
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• 2005

Microsatellites are short tandem repeated nucleotide sequences that are present throughout the human genome. Variations in the repeat number or a loss of heterozygosity around the microsatellites have been termed a microsatellite alteration (MA). A MA reflects the genetic instability caused by an impairment in the DNA mismatch repair system and is suggested to be a novel tumorigenic mechanism. A number of studies have reported that MA in the DNA extracted from the plasma occurs at varying frequencies among patients with a non-small cell lung carcinoma (NSCLC). The genomic DNA from 9 subjects with a non-small cell lung cancer (squamous cell cancer 6, adenocarcinoma 2, non-small cell lung cancer1) and 9 age matched non-cancer control subjects (AMC: tuberculosis 3, other inflammatory lung disease 6) and 12 normal control subjects (NC) were extracted from the peripheral blood leukocytes and plasma. Three microsatellite loci were amplified with the primers targeting the Gene Bank sequence D21S1245, D3S1300, and D3S1234. MA in the form of an allelic loss or a band shift was examined with 6% polyacrylamide gel electrophoresis and silver staining. None (0/12) of the NC subjects less than 40 years of age showed a MA in any of the three markers, while 88.9%(8/9) of the AMC above 40 showed a MA in at least one of the three markers (p<0.05). Sixty percent(6/10) of the control subjects with a smoking history showed a MA in one of the three markers, while 9.1%(1/11) of the control subjects without smoking history showed a MA (p<0.05). However, not only did 66.7%(6/9) of lung cancer patients show a MA in at least one of the three markers but so did 88.9%(8/21) of the AMC patients (p>0.05). In conclusion, a MA in the D21S1245, D3S1300, and D3S1234 loci using DNA extracted from the plasma was detected in 66.7% of lung cancer while no MA was found in the young non-smoking control subjects. However, many of the non-cancer control subjects (aged smokers) also showed a MA, which compromised the specificity of the MA analysis as a screening test. Therefore, a further study with a larger sample size will be needed.

• Korean Journal of Forensic Psychology
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• v.13 no.2
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• pp.121-145
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• 2022

The current study applied the random forest algorithm to Korean crime victim survey data collected biennially between 2010 and 2018 to explore the relationship between crime/victim characteristics and the victim's criminal damages. A total of 3,080 cases including gender, age (life cycle stage), type of crime, perpetrator acquisition, repeated victimization, psychological damage (depression, isolation, extreme fear, somatic symptoms, interpersonal problems, moving out to avoid people, suicidal impulses, suicide attempts), and emotional changes after victimization (changes in self-protection confidence, self-esteem, confidence in others, confidence in legal institutions, and respect for Korean legal system/law) were analyzed. Considering the features of data that are difficult to apply traditional statistical techniques, this study implemented random forest algorithms to predict crime and victim characteristics using the victim's criminal damages (psychological damage and emotional change) and selected good predictors using VSURF function in VSURF package for R. As a result of the analysis, it was confirmed that the relationship between the type of crime and depression, extreme fear, somatic symptoms, and interpersonal problems, between perpetrator acquisition and somatic symptoms and interpersonal problems, and between repeated victimization and changes in respect for Korean legal system/law. Gender and life cycle stage (youth/adult/elderly) were found to be related to extreme fear and changes in self-protection confidence, respectively. However, more empirical evidence should be aggregated to explain the results as meaningful. The results of this study suggest that it is necessary to enhance the experts' knowledge and educate them on cases about the relationship between crime/victim characteristics and criminal damage. Strengthening their interview strategy and knowledge about law/rules were also needed to increase the effectiveness of the Korean victim assessment system.

• Journal of Oral Medicine and Pain
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• v.31 no.1
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• pp.1-16
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• 2006

The most important progress in diagnostic sciences is the increased sensitivity and specificity in diagnostic procedures due to the development of micromethodologies and increasing availability of immunological and molecular biological reagents. The technological advances led to consider the diagnostic use of saliva for an array of analytes and DNA source. The purpose of the present study was to compare DNA from saliva with those from blood and buccal swab, to evaluate diagnostic and forensic application of saliva, to investigate the changes of genomic DNA in saliva according to the storage temperature and period of saliva samples, and to evaluate the integrity of the DNA from saliva stored under various storage conditions by PCR analysis. Peripheral venous blood, unstimulated whole saliva, stimulated whole saliva, and buccal swab were obtained from healthy 10 subjects (mean age: $29.9{\pm}9.8$ years) and genomic DNA was extracted using commercial kit. For the study of effects of various storage conditions on genomic DNA from saliva, stimulated whole saliva were obtained from healthy 20 subjects (mean age: $32.3{\pm}6.6$ years). After making aliquots from fresh saliva, they were stored at room temperature, $4^{\circ}C$, $-20^{\circ}C$, and $-70^{\circ}C$. Saliva samples after lyophilization and dry-out procedure were stored at room temperature. After 1, 3, and 5 months, the same experiment was performed to investigate the changes in genomic DNA in saliva samples. In case of saliva aliquots stored at room temperature and dry-out samples, the results in 2 weeks were also included. Integrity of DNA from saliva stored under various storage conditions was also evaluated by PCR amplification analysis of $\beta$-globin gene fragments (989-bp). The results were as follows: 1. Concentration of genomic DNA extracted from saliva was lower than that from blood (p<0.05), but there were no significant differences among various types of saliva samples. Purities of genomic DNA extracted from stimulated whole saliva and lyophilized one were significantly higher than that from blood (p<0.05). Purity of genomic DNA extracted from buccal swab was lower than those from various types of saliva samples (p<0.05). 2. Concentration of genomic DNA from saliva stored at room temperature showed gradual reduction after 1 month, and decreased significantly in 3 and 5 months (p<0.05, p<0.01, respectively). Purities of DNA from saliva stored for 3 and 5 months showed significant differences with those of fresh saliva and stored saliva for 1 month (p<0.05). 3. In the case of saliva stored at $4^{\circ}C$ and $-20^{\circ}C$, there were no significant changes of concentration of genomic DNA in 3 months. Concentration of DNA decreased significantly in 5 months (p<0.05). 4. There were no significant differences of concentration of genomic DNA from saliva stored at $-70^{\circ}C$ and from lyophilized one according to storage period. Concentration of DNA showed decreasing tendency in 5 months. 5. Concentration of genomic DNA immediately extracted from saliva dried on Petri dish were 60% compared with that of fresh saliva. Concentration of DNA from saliva stored at room temperature after dry-out showed rapid reduction within 2 weeks (p<0.05). 6. Amplification of $\beta$-globin gene using PCR was successful in all lyophilized saliva stored for 5 months. At the time of 1 month, $\beta$-globin gene was successfully amplified in all saliva samples stored at $-20^{\circ}C$ and $-70^{\circ}C$, and in some saliva samples stored at $4^{\circ}C$. $\beta$-globin gene was failed to amplify in saliva stored at room temperature and dry-out saliva.